GARNet Research Roundup: June 26th 2020

This edition of the GARNet Research Roundup begins with a study from Nottingham and Leeds that looks at the much-neglected subject of the control of floral arrest. The second paper from Edinburgh identifies a signaling role for the co-opted transposable elements ALP1 and ALP2 in Arabidopsis. Hans-Wilhelm Nützmann from the University of Bath leads the next study that looks at the co-regulation of clustered biosynthetic pathway genes. The fourth paper is from Cambridge and looks at the role of the ASY1 protein during meiotic recombination. The next paper is from Durham and looks at the role of GA-regulated DELLA proteins in the regulation of stomatal aperature.

The next five papers have a methods-type application that should be useful to other researchers. Firstly a research team led from Oxford highlights an improved protocol for the proteome-analysis technique of RNA interactome capture. Secondly researchers from UEA introduce the NATpare tool, which is a pipeline for high-throughput prediction and functional analysis of nat-siRNAs. The third ‘methods’ paper is from the University of Warwick where they have developed novel markers for protoplast-based analyses of hormone signaling. The fourth paper is a protocol for using CRISPR-Cas9 gene editing in Brachypodium. The final ‘methods-type’ paper is from Alison Smith’s group in Cambridge and has developed a riboswitch-based resource for use in the model alga Chlamydomonas reinhardtii.

The eleventh paper is led from the University of Glasgow and looks at the activity of the circadian clock in Arabidopsis roots. The next paper introduces genes from the parasitic plant Striga hermonthica into Arabidopsis to show that strigolactone signaling can replace GA signaling in the control of seed germination. The final two papers are focused on research in wheat, first led from the University of Leicester that looks at recombination in durum wheat and secondly from Rothamsted in which they have identified a whole family of NPF membrane transporter genes.


Ware A, Walker CH, Šimura J, et al (2020) Auxin export from proximal fruits drives arrest in temporally competent inflorescences Nat Plants. 2020;10.1038/s41477-020-0661-z. doi:10.1038/s41477-020-0661-z

Open Access with this link rdcu.be/b4rmT

Al Ware and Catriona Walker are co-first authors on this study from the Universities of Nottingham and Leeds. They have looked at the factors that control the timing of floral arrest in Arabidopsis. They discover that there is a minimum number and optimal positioning of fruits that is necessary for floral arrest, as well as looking into the role of auxin transport in this process.


Velanis CN, Perera P, Thomson B, et al (2020) The domesticated transposase ALP2 mediates formation of a novel Polycomb protein complex by direct interaction with MSI1, a core subunit of Polycomb Repressive Complex 2 (PRC2) PLoS Genet. 2020;16(5):e1008681. doi:10.1371/journal.pgen.1008681

Open Access

Christos Velanis is first author on this research led by the Goodrich group at the University of Edinburgh that looked at the function of the Arabidopsis ANTAGONIST OF LIKE HETEROCHROMATIN PROTEIN 1 (ALP1) gene, which has arose by domestication of the Harbinger class of transposable elements (TEs). ALP1 is a component of the POLYCOMB REPRESSIVE COMPLEX 2 (PRC2) but yet its functional significance is not yet known. They also identify the related ALP2 gene and find that it interacts with MULTICOPY SUPPRESSOR OF IRA1 (MSI1) as part of the PRC2.


Nützmann HW, Doerr D, Ramírez-Colmenero A, et al (2020) Active and repressed biosynthetic gene clusters have spatially distinct chromosome states Proc Natl Acad Sci U S A. 2020;201920474. doi:10.1073/pnas.1920474117

Hans-Wilhelm Nützmann is a now a member of faculty at the University of Bath but led this research as a member of the Osbourn group at the John Innes Centre. They use Hi-C and related techniques to study the control of expression of clustered biosynthetic pathway genes in Arabidopsis. This study reveals potential mechanisms that suggest gene clustering in the one-dimensional chromosome is accompanied by compartmentalization of the 3D chromosome.


Lambing C, Kuo PC, Tock AJ, Topp SD, Henderson IR (2020) ASY1 acts as a dosage-dependent antagonist of telomere-led recombination and mediates crossover interference in Arabidopsis Proc Natl Acad Sci U S A. 2020;201921055. doi:10.1073/pnas.1921055117

Open Access

Christophe Lambing is first author on this study from the Henderson lab at the University of Cambridge that investigates the role of the ASY1 protein in the control of recombination frequency during meiosis. ASY1 is localized in an ascending telomere-to-centromere gradient and this informs the role that it plays to antagonize telomere-recombination to ensure this occurs in more gene-rich regions of the chromosomes.


Sukiran NA, Steel PG, Knight MR (2020) Basal stomatal aperture is regulated by GA-DELLAs in Arabidopsis J Plant Physiol. 2020;250:153182. doi:10.1016/j.jplph.2020.153182

Nur Afiqah Sukiran is the first author of this study from the Durham University that investigates the role of DELLA proteins in the regulation of stomatal aperature. They also find that the GID1 gibberellin receptor is necessary for optimal basal stomatal aperture.

Professor Marc Knight will be discussing his labs work on the #GARNetPresents webinar on June 30th 2020


Bach-Pages M, Homma F, Kourelis J, et al (2020) Discovering the RNA-Binding Proteome of Plant Leaves with an Improved RNA Interactome Capture Method. Biomolecules. 2020;10(4):661 doi:10.3390/biom10040661

Open Access

Marcel Bach-Pages is first author on this research led from the University of Oxford that has improved the proteome-analysis technique of RNA interactome capture (RIC) to identify 717 RNA Binding Proteins (RBP) from Arabidopsis. Many of these RBPs exhibit unconventional modes of RNA binding and uncovered greater diversity in the number of proteins for which RNA binding is an important part of their function.


Thody J, Folkes L, Moulton V (2020) NATpare: a pipeline for high-throughput prediction and functional analysis of nat-siRNAs Nucleic Acids Res. 2020;gkaa448. doi:10.1093/nar/gkaa448

Joshua Thody leads this work from the University of East Anglia in which the authors present a new software pipeline, called NATpare, for prediction and functional analysis of Natural antisense transcript-derived small interfering RNAs (nat-siRNAs) using sRNA and degradome sequencing data. Although this tool could be used to analyse data from different experimental systems it is benchmarked using Arabidopsis data and the authors show that it could rapidly identify a comprehensive set of nat-siRNAs from different tissues and that are produced in response to different stresses.


Lehmann S, Dominguez-Ferreras A, Huang WJ, Denby K, Ntoukakis V, Schäfer P (2020) Novel markers for high-throughput protoplast-based analyses of phytohormone signaling. PLoS One. 2020;15(6):e0234154. doi:10.1371/journal.pone.0234154

Open Access

Silke Lehmann leads this work from the University of Warwick that has generated a community-resource of 18 promoter::luciferase constructs that respond to different phytohormones. In addition they suggest an experimental setup for high-throughput analyses in which these new reporter constructs might be used to screen for biological and environmental stimuli that effect hormone-mediated gene expression.


Hus K, Betekhtin A, Pinski A, et al (2020) A CRISPR/Cas9-Based Mutagenesis Protocol for Brachypodium distachyon and Its Allopolyploid Relative, Brachypodium hybridum. Front Plant Sci. 2020;11:614. doi:10.3389/fpls.2020.00614 Open Access

This Polish project is led by Karolina Hus and includes co-authors from Cambridge and Aberystwyth. They have developed a protocols for CRISPR-Cas9 gene editing in Brachypodia species. As proof of concept they target two cyclin-dependent kinases (CDKG1 and CDKG2) that are involved in DNA recombination.


Mehrshahi P, Nguyen GTDT, Gorchs Rovira A, et al (2020) Development of Novel Riboswitches for Synthetic Biology in the Green Alga Chlamydomonas ACS Synth Biol. 2020;10.1021/acssynbio.0c00082. doi:10.1021/acssynbio.0c00082

Open Access

Payam Mehrshahi is the first author on this Academia-Industry collaboration led from the University of Cambrige. They have used a synthetic biology approach to assess the effectiveness of riboswitchs (RNA regulatory elements) in the control of gene expression in the model alga Chlamydomonas reinhardtii.


Nimmo HG, Laird J, Bindbeutel R, Nusinow DA (2020) The evening complex is central to the difference between the circadian clocks of Arabidopsis thaliana shoots and roots Physiol Plant. 2020;10.1111/ppl.13108. doi:10.1111/ppl.13108 Open Access

Hugh Nimmo from the University of Glasgow is lead author on this UK-USA collaboration that has looked at the operation of the circadian clock in root tissues and in particularly how it responds to light quality. They found that plants with mutations in certain genes that make up the circadian clock evening complex have root-specific effects, confirming that the shoot and root clocks response to differently to light signals.


Bunsick M, Toh S, Wong C, et al (2020) SMAX1-dependent seed germination bypasses GA signalling in Arabidopsis and Striga Nat Plants. 2020;10.1038/s41477-020-0653-z. doi:10.1038/s41477-020-0653-z

Michael Bunsick is first author of this Canadian-led study that includes Julie Scholes from the University of Sheffield as a co-author. Leading from a curiosity about the relationship between host root exudates and the parasitic plant Striga hermonthica, they were led to find that expression of Striga strigolactone-hormone receptor proteins in Arabidopsis is able to bypass the requirement for GA in seed germination. This demonstrates both how the Striga might sense host signals and that there is no absolute requirement for GA-during seed germination.


Desjardins SD, Ogle DE, Ayoub MA, et al (2020) MutS homologue 4 and MutS homologue 5 maintain the obligate crossover in wheat despite stepwise gene loss following polyploidization Plant Physiol. 2020;pp.00534.2020. doi:10.1104/pp.20.00534

Open Access

Stuart Desjardins is first author on his research led from the University of Leicester. They work with allotetraploid (AABB) durum wheat and show that this plant undergoes two pathways of meiotic recombination. They show that the class I pathway requires the MSH4 and MSH5 (MutSγ) proteins and the authors show that these genes are absent in hexaploid (AABBDD) wheat. These findings enable the authors to speculate about the function of these proteins in allopolyploid wheat.


Wang H, Wan Y, Buchner P, King R, Ma H, Hawkesford MJ (2020) Phylogeny and gene expression of the complete NITRATE TRANSPORTER 1/PEPTIDE TRANSPORTER FAMILY (NPF) in Triticum aestivum L J Exp Bot. 2020;eraa210. doi:10.1093/jxb/eraa210 Open Access

Huadun Wang is first author on this manuscript that is led from Rothamsted Research and includes Chinese collaborators. They investigate the 331 member family of wheat NPF genes that encode membrane transporters that transport a diverse range of substrates. Phylogenetically these wheat NPF genes are closely clustered with Arabidopsis, Brachypodium and rice orthologs and this study and lays the foundation for their further functional analysis in wheat.

GARNet Research Roundup: May 29th 2020

This bumper GARNet Research Roundup begins with two sets of papers in related areas. First are three papers that investigate the biology of plasmodesmatata. These include work from the Faulkner lab at the JIC, the Band lab at Nottingham and a broad European collaboration that includes co-authors from Durham, Cambridge and St Andrews.

The second set of two papers features work on different species of Kalanchoë, which is a key model for the study of CAM. This research is from the Hartwell lab in Liverpool and the Borland lab in Newcastle.

The fifth paper is from RHUL and looks at the relationship between nucleus and chloroplast signaling. The sixth paper is from QMUL and introduces research suggesting that a rethink is needed in our understanding of the relationship between chloroplast movement and photoprotection.

The next paper is from the University of the West of England and looks at the effect of ionising radiation on multiple generation of Arabidopsis growth whilst the eighth paper investigates the relationship between starch degradation and stomatal movements in guard cells and includes co-authors from Essex and Glasgow.

The next two papers include research undertaken in Cambridge; firstly looking at the integration of signalling between karrikin and strigolactone signaling in rice and secondly identifying a novel mRNA thermoswitch that controls thermomorphogenesis.

The next paper is a pan-European project led from Nottingham that has characterised the role of the CEP5 peptide during regulation of osmostic stress, drought and auxin signaling.

The twelveth paper is from the University of Warwick and also looks at the auxin response, this time during senescence. The next paper as well includes co-authors from Warwick in a study that investigates the global regulatory role for the histone acetyltransferase GCN5.

The penultimate paper includes co-authors from Norwich Research Park looks at the evolution of immune NLR signaling between closely related species. The final paper includes Patrick Hussey from Durham as a co-author in a Spanish study that identifies an uncharacterized compartment of the plant vacuolar trafficking pathway.


Cheval C, Samwald S, Johnston MG, de Keijzer J, Breakspear A, Liu X, Bellandi A, Kadota Y, Zipfel C, Faulkner C (2020) Chitin perception in plasmodesmata characterizes submembrane immune-signaling specificity in plants. Proc Natl Acad Sci U S A. 2020 Apr 28;117(17):9621-9629. doi: 10.1073/pnas.1907799117 Open Access

Cecilia Cheval, Sebastian Samwald and Matthew Johnston are co-first authors on this work from the Faulkner lab at the John Innes Centre. They looked at a plasmodesmata-localised plasma membrane microdomain, which hosts specific receptors and responses. They showed that immune chitin signalling requires the plasmodesmal PM localised LYM2 and LYK4 proteins. Overall this demonstrates that distinct membrane domains can integrate common signals to produce a localized response.

https://www.pnas.org/content/117/17/9621.long

Brault ML, Petit JD, Immel F, Nicolas WJ, Glavier M, Brocard L, Gaston A, Fouché M, Hawkins TJ, Crowet JM, Grison MS, Germain V, Rocher M, Kraner M, Alva V, Claverol S, Paterlini A, Helariutta Y, Deleu M, Lins L, Tilsner J, Bayer EM (2020) Multiple C2 domains and transmembrane region proteins (MCTPs) tether membranes at plasmodesmata. EMBO Rep. 2019 Aug;20(8):e47182. doi: 10.15252/embr.201847182 Open Access

Marie Brault works with Emmualle Bayer is first author on this French-led pan-European study that includes co-authors from Durham, Cambridge and St Andrews. They investigate the plasmodesmal plasma membrane and show that Multiple C2 domains and transmembrane region proteins (MCTP) are needed to tether ER-PM linkages at this location. They show Atmctp3/Atmctp4 loss of function double mutants have plant developmental defects demonstrating that MCTPs also play a significant role in cell-to-cell signalling.

https://www.embopress.org/doi/full/10.15252/embr.201847182#.XSRrrlB2xG0.twitter

Mellor NL, Voß U, Janes G, Bennett MJ, Wells DM, Band LR (2020) Auxin fluxes through plasmodesmata modify root-tip auxin distribution. Development. doi: 10.1242/dev.181669 Open Access

Nathan Mellor leads this research from the University of Nottingham that has developed a model to explain auxin movement around the Arabidopsis root tip. They propose that carrier mediated movement is not sufficient foir this and that there must be a symplastic route via plasmodesmata. This introduces plasmodesmata as playing a key role in hormone signaling.

https://dev.biologists.org/content/147/6/dev181669

GARNet committee member Yoselin Benitez-Alfonso discusses her labs work on plasmodesmata in the first #GARNetPresents webinar


Boxall SF, Kadu N, Dever LV, Kneřová J, Waller JL, Gould PJD, Hartwell J (2020) Kalanchoë PPC1 Is Essential for Crassulacean Acid Metabolism and the Regulation of Core Circadian Clock and Guard Cell Signaling Genes. Plant Cell. doi: 10.1105/tpc.19.00481

Susie Boxall leads this study from the Hartwell lab at the University of Liverpool in which they investigate the role of the phosphoenolpyruvate carboxylase gene in the CAM-plant Kalanchoë laxiflora. They use RNA interference to silence the PPC1 gene and show that these transgenic plants have defects in guard cell signaling and regulation of the circadian clock. These findings provide direct evidence that the regulatory patterns of key guard cell signaling genes are linked with the characteristic inverse pattern of stomatal opening and closing during CAM.

http://www.plantcell.org/content/32/4/1136.long

Abraham PE, Hurtado Castano N, Cowan-Turner D, Barnes J, Poudel S, Hettich R, Flütsch S, Santelia D, Borland AM (2020) Peeling back the layers of Crassulacean acid metabolism: functional differentiation between Kalanchoë fedtschenkoi epidermis and mesophyll proteomes. Plant J. doi: 10.1111/tpj.14757 Open Access

Paul Abraham is first author on this work from the Borland lab at the University of Newcastle. They are working with the CAM species Kalanchoë fedtschenkoi and here perform a large-scale proteomics analysis of the epidermis and mesophyll cell layers. This reveals that different proteins and biological processes are enriched in each layer, showing how plants adapt to hot and dry environments by modifying leaf physiology for improved plant sustainability.


Loudya N, Okunola T, He J, Jarvis P, López-Juez E (2020) Retrograde signalling in a virescent mutant triggers an anterograde delay of chloroplast biogenesis that requires GUN1 and is essential for survival Philos Trans R Soc Lond B Biol Sci. 2020;375(1801):20190400. doi:10.1098/rstb.2019.0400 Open Access

Naresh Loudya from Royal Hollaway University of London is first author on this work that investigates the relationship between nucleus and chloroplast gene expression in the control of chloroplast biogenesis. They analyse the cue8 mutant that shows differential changes in the activity of plastid-encoded and nucleus-encoded polymerases.

Naresh discussed this paper on the GARNet Community podcast.


Wilson S, Ruban AV (2020) Rethinking the influence of chloroplast movements on non-photochemical quenching and photoprotection. Plant Physiol. 2020 May 13. pii: pp.00549.2020. doi: 10.1104/pp.20.00549 Open Access

Sam Wilson is first author on this work from the Ruban lab at the Queen Mary University of London. In this study they have assessed the relationship between blue light induced chloroplast relocation and high-light tolerance. Their data argues against the existence of a chloroplast movement-dependent component of the non-photochemical quenching (NPQ) respose. Therefore the authors suggest that thinking on the influence of chloroplast movements on photoprotection should be reevaluated.


Caplin NM, Halliday A, Willey NJ (2020) Developmental, Morphological and Physiological Traits in Plants Exposed for Five Generations to Chronic Low-Level Ionising Radiation. Front Plant Sci. doi: 10.3389/fpls.2020.00389 Open Access

Nicol Caplin is first author on this research from the University of the West of England that looked at the effects of ionising radiation (IR) on seven generations of Arabidopsis growth. They found that although chronic exposure to IR caused some individual trait changes, these are not carried across generations at the population level but still call for more research in this area to be sure of the current regulations provided by the International Commission for Radiological Protection (ICRP).

https://www.frontiersin.org/articles/10.3389/fpls.2020.00389/full

Flütsch S, Wang Y, Takemiya A, Vialet-Chabrand SR, Klejchova M, Nigro A, Hills A, Lawson T, Blatt MR, Santelia D (2020) Guard Cell Starch Degradation Yields Glucose for Rapid Stomatal Opening in Arabidopsis. Plant Cell. doi: 10.1105/tpc.18.00802

This Swiss-led study has Sabrina Flütsch as first author and co-authors from Essex and Glasgow. They looked at the integration of starch degradation in guard cells with the kinetics of stomatal reopening. The timing of rapid stomatal unopening was unchanged in starch degrading mutants but there were alterations in slower responses, most likely due to alterations in the composition of guard cell starch metabolites.


Choi J, Lee T, Cho J, Servante EK, Pucker B, Summers W, Bowden S, Rahimi M, An K, An G, Bouwmeester HJ, Wallington EJ, Oldroyd G, Paszkowski U (2020) The negative regulator SMAX1 controls mycorrhizal symbiosis and strigolactone biosynthesis in rice. Nat Commun. doi: 10.1038/s41467-020-16021-1 Open Access

This research is led from the Paszkowski lab at the University of Cambridge by Jeongmin Choi. They have found that the rice ortholog of Arabidopsis Suppressor of MAX2-1 plays a novel role to link the pre-symbiotic perception of arbuscular mycorrhizal fungi with karrikin and strigolactone signaling. This response functions through a modification of the D14L signalling pathway.


Chung BYW, Balcerowicz M, Di Antonio M, Jaeger KE, Geng F, Franaszek K, Marriott P, Brierley I, Firth AE, Wigge PA (2020) An RNA thermoswitch regulates daytime growth in Arabidopsis. Nat Plants. doi: 10.1038/s41477-020-0633-3

This Wigge lab-led collaboration includes Betty Chung as first author and investigate the role of the PIF7 messenger RNA as a thermoswitch that activates the thermomorphogenesis pathway. This is controlled by the formation of an RNA hairpin within the mRNA and they show that this mechanism is conserved so controls translation of other mRNAs, enabling the plant to respond and adapt rapidly to high temperatures.


Smith S, Zhu S, Joos L, Roberts I, Nikonorova N, Vu LD, Stes E, Cho H, Larrieu A, Xuan W, Goodall B, van de Cotte B, Waite JM, Rigal A, R Harborough SR, Persiau G, Vanneste S, Kirschner GK, Vandermarliere E, Martens L, Stahl Y, Audenaert D, Friml J, Felix G, Simon R, Bennett M, Bishopp A, De Jaeger G, Ljung K, Kepinski S, Robert S, Nemhauser J, Hwang I, Gevaert K, Beeckman T, De Smet I (2020) The CEP5 peptide promotes abiotic stress tolerance, as revealed by quantitative proteomics, and attenuates the AUX/IAA equilibrium in Arabidopsis. Mol Cell Proteomics. 2020 May 13. pii: mcp.RA119.001826. doi: 10.1074/mcp.RA119.001826 Open Access

Stephanie Smith at the University of Nottingham is first author on this collaboration between researchers in 8 different countries. They use quantitative proteomics to assess the role of the CEP8 peptide in the response to osmotic and drought stress and in the control of auxin signaling.


Gören-Sağlam N, Harrison E, Breeze E, Öz G, Buchanan-Wollaston V (2020) Analysis of the impact of indole-3-acetic acid (IAA) on gene expression during leaf senescence in Arabidopsis thaliana. Physiol Mol Biol Plants. doi: 10.1007/s12298-019-00752-7

Nihal Gören-Sağlam is first author on this study from the University of Warwick in which they investigate the role of externally applied auxin on senescence in Arabidopsis thaliana. They show that PSII activity, as a determinant of chlorophyll fluorescence, declined after auxin treatment and that this response changed across different leaves.


Kim S, Piquerez SJM, Ramirez-Prado JS, Mastorakis E, Veluchamy A, Latrasse D, Manza-Mianza D, Brik-Chaouche R, Huang Y, Rodriguez-Granados NY, Concia L, Blein T, Citerne S, Bendahmane A, Bergounioux C, Crespi M, Mahfouz MM, Raynaud C, Hirt H, Ntoukakis V, Benhamed M (2020) GCN5 modulates salicylic acid homeostasis by regulating H3K14ac levels at the 5′ and 3′ ends of its target genes. Nucleic Acids Res. doi: 10.1093/nar/gkaa369 Open Access

This French-led study includes Soonkap Kim as first author and co-authors from the University of Warwick. They analysed the role of the histone acetyltransferase GCN5 in global control of gene expression. They used several methodologies (ATAC-seq, ChIP-seq and RNA-seq) to assess the effect of GCN5 loss-of-function on the expression and epigenetic regulation of its target genes.


Baggs E, Monroe JG, Thanki AS, O’Grady R, Schudoma C, Haerty W, Krasileva KV (2020) Convergent Loss of an EDS1/PAD4 Signaling Pathway in Several Plant Lineages Reveals Co-evolved Components of Plant Immunity and Drought Response. Plant Cell. doi: 10.1105/tpc.19.00903 Open Access

This research is led by Erin Baggs in the Krasileva lab at the University of California Berkeley and includes co-authors from Norwich Research Park. They assessed the variation in nucleotide-binding leucine-rich repeat receptors (NLRs) involved in plant immunity, focusing on closely related species that have different NLR compositions. Loss of NLRs corresponds to other changes in downstream immune signaling complexes. This excellent extensive multi-omic analysis provides evolutionary evidence for the rewiring of immunity in some plant lineages.

http://www.plantcell.org/content/early/2020/05/14/tpc.19.00903.long

Delgadillo MO, Ruano G, Zouhar J, Sauer M, Shen J, Lazarova A, Sanmartín M, Lai LTF, Deng C, Wang P, Hussey PJ, Sánchez-Serrano JJ, Jiang L, Rojo E (2020) MTV proteins unveil ER- and microtubule-associated compartments in the plant vacuolar trafficking pathway. Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1919820117

María Otilia Delgadillo is first author on this Spanish-led study that includes Patrick Hussey from Durham as a co-author. The study identifies 13 components of the vacuolar trafficking machinery through a genetic screen for mutants that abnormally secrete the synthetic vacuolar cargo VAC2. Eight of these components localize at the interface between the trans-Golgi network (TGN) and the multivesicular bodies (MVBs), which excitingly reveals a previously uncharacterized compartment of the plant vacuolar trafficking pathway.

https://www.pnas.org/content/117/20/10623

GARNet Research Roundup: November 1st 2019

This edition of the GARNet Research Roundup begins with a pan-UK study that has identified a gene involved in starch granule formation in polyploid wheat. Second is a study from Canterbury that identifies Arabidopsis QTLs involved in alternative splicing. Third is research from Cambridge that investigates the role of the nuclear circadian oscillator on sub-cellular calcium fluctuations. The fourth paper describes the development of a computer-vision tool designed for automated measurements of wheat spikes in the field. The fifth paper is a Korean-led study that has identified a transcription factor involved in pollen development and includes co-authors from Leicester. Last is a study from the University of Warwick that has looked into light-regulated gene expression during bulb initiation in onion.


Chia T, Chirico M, King R, Ramirez-Gonzalez R, Saccomanno B, Seung D, Simmonds J, Trick M, Uauy C, Verhoeven T, Trafford K (2019) A carbohydrate-binding protein, B-GRANULE CONTENT 1, influences starch granule size distribution in a dose-dependent manner in polyploid wheat. J Exp Bot. doi: 10.1093/jxb/erz405
Open Access

Tansy Chia is lead author on this study that brings together three of the UKs major plant breeding research centres; NIAB, Rothamsted and the JIC. They take advantage of the new genomic tools and mutant populations available in wheat to characterize the complex role of the BGC1 (B-GRANULE CONTENT 1) gene during formation of B-type starch granules.


Khokhar W, Hassan MA, Reddy ASN, Chaudhary S, Jabre I, Byrne LJ, Syed NH (2019) Genome-Wide Identification of Splicing Quantitative Trait Loci (sQTLs) in Diverse Ecotypes of Arabidopsis thaliana Front Plant Sci. doi: 10.3389/fpls.2019.01160
Open Access

This work from Canterbury Christ Church University is led by Waqas Khokhar and Naeem Syed. They analysed 666 diverse Arabidopsis ecotypes to look for splicing quantitative trait loci (sQTLs)] that alter rates of alternative splicing. They identified a number of trans-sQTLs hotspots that align with known functional SNPs. This study provides the first sQTL resource across diverse ecotypes that can be used to compliment other available genome and transcriptome datasets.


Martí Ruiz MC, Jung HJ, Webb AAR (2019) Circadian gating of dark-induced increases in chloroplast- and cytosolic-free calcium in Arabidopsis. New Phytol. doi: 10.1111/nph.16280

María Carmen Martí Ruiz is lead author on this research undertaken in Alex Webb’s lab in Cambridge. They have looked at the role of the circadian clock in the control of calcium fluctuations in both cytoplasm and chloroplast stroma. They show the extent these changes are dependent on a nuclear-encoded circadian oscillator, adding a new role in sub-cellular Ca2+ signaling to the circadian machinery.


Sadeghi-Tehran P, Virlet N, Ampe EM, Reyns P, Hawkesford MJ (2019) DeepCount: In-Field Automatic Quantification of Wheat Spikes Using Simple Linear Iterative Clustering and Deep Convolutional Neural Networks. Front Plant Sci. doi: 10.3389/fpls.2019.01176
Open Access

Pouria Sadeghi-Tehran leads this theorectical study from Rothamsted Research that has developed an automated ‘DeepCount’ system for quantifying wheat spikes in the field. They use a deep convolutional neural network to test their program on field images and compare this method to other automated systems based on edge detection techniques and morphological analysis. Overall they show that this method has potential toward development of a portable and smartphone-assisted wheat-ear counting systems, that will have the associated benefits of counting accuracy and reduced labour.

https://www.frontiersin.org/articles/10.3389/fpls.2019.01176/full

Oh SA, Hoai TNT, Park HJ, Zhao M, Twell D, Honys D, Park SK (2019) MYB81, a microspore-specific GAMYB transcription factor, promotes pollen mitosis I and cell lineage formation in Arabidopsis. Plant J. doi: 10.1111/tpj.14564

Mingmin Zhao and David Twell are co-authors on this project led by Sung‐Aeong Oh and Korean colleagues. After screening pollen cell patterning mutants they have identified a role for the GAMYB transcription factor MYB81 during a narrow window prior to pollen mitosis I. They demonstrate that this protein is essential for establishing the male cell lineage in Arabidopsis pollen.


Rashid MHA, Cheng W, Thomas B (2019) Temporal and Spatial Expression of Arabidopsis Gene Homologs Control Daylength Adaptation and Bulb Formation in Onion (Allium cepa L.). Sci Rep. doi: 10.1038/s41598-019-51262-1 Open Access

This collaboration between the University of Warwick and Bangladesh Agricultural University is led by Harun Ar Rashid. They look at genetic regulation of light-dependent onion bulb initiation by growing plants under short and long days and testing the expression of known regulators of flowering time; AcFT, Ac LFY and AcGA3ox1. They also performed tissue-specific analysis to demonstrate differences in expression patterns that begin to suggest how these genes are involved in bulb initiation.

https://www.nature.com/articles/s41598-019-51262-1

GARNet Research Roundup: September 24th 2019

Due to a significant delay this GARNet Research Roundup is a bumper overview of recent(ish) publications across discovery-led plant science, which have at least one contributor from a UK institution.

These can be (very) loosely separated into the following categories:

Circadian Clock: Greenwood et al, PloS Biology. Belbin et al, Nature Communications.

Environmental responses: Rodríguez-Celma et al, PNAS. Walker and Bennett, Nature Plants. Conn et al, PLoS Comput Biology. de Jong et al,PLoS Genetics. Molina-Contreras et al,The Plant Cell.

Defence signaling: Van de Weyer et al, Cell.Hurst et al, Scientific Reports. Xiao et al, Nature. Wong et al, PNAS.

Cell Biology: Miller et al, The Plant Cell. Coudert et al, Current Biology. Burgess et al,The Plant Cell. Harrington et al, BMC Plant Biology.

Metabolism: Jia et al, J Biol Chem. Perdomo et al, Biochem J. Gurrieri et al, Frontiers in Plant Science. Mucha et al, The Plant Cell. Atkinson et al, JXBot.

Cell Wall Composition: Wightman et al, Micron. Milhinhos et al, PNAS.

Signaling: Hartman et al, Nature Communications. Dittrich et al, Nature Plants. Villaécija-Aguilar et al, PLoS Genetics


Greenwood M, Domijan M, Gould PD, Hall AJW, Locke JCW (2019) Coordinated circadian timing through the integration of local inputs in Arabidopsis thaliana. PLoS Biol. 17(8):e3000407. doi: 10.1371/journal.pbio.300040 Open Access

Lead author is Mark Greenwood. UK contribution from The Sainsbury lab University of Cambridge, University of Liverpool and Earlham Institute. Using a mixture of experimental and modeling this paper shows that individual organs have circadian clocks that runs at different speeds.


Belbin FE, Hall GJ, Jackson AB, Schanschieff FE, Archibald G, Formstone C, Dodd AN (2019) Plant circadian rhythms regulate the effectiveness of a glyphosate-based herbicide. Nat Commun. 2019 Aug 16;10(1):3704. doi: 10.1038/s41467-019-11709-5 Open Access

Lead author is Fiona Belbin. UK contribution from University of Bristol and Syngenta Jealott’s Hill. Activity of the circadian clock determines that the plant response to the herbicide glyphosate is lessened at dusk, promoting the idea of agricultural chronotherapy. Fiona discusses this paper on the GARNet Community Podcast.


Rodríguez-Celma J, Connorton JM, Kruse I, Green RT, Franceschetti M, Chen YT, Cui Y, Ling HQ, Yeh KC, Balk J (2019) Arabidopsis BRUTUS-LIKE E3 ligases negatively regulate iron uptake by targeting transcription factor FIT for recycling. Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1907971116 Open Access

Lead author is Jorge Rodríguez-Celma. UK contribution from John Innes Centre, University of East Anglia.The Arabidopsis E3 ubiquitin ligases, BRUTUS-LIKE1 (BTSL1) and BTSL2 target the FIT transcription factor for degradation, altering the plant response to harmful level of iron.


Walker CH, Bennett T (2019) A distributive ‘50% rule’ determines floral initiation rates in the Brassicaceae. Nat Plants. doi: 10.1038/s41477-019-0503-z
Lead author Catriona Walker. UK contribution from the University of Leeds. The authors introduce the 50%-rule that defines the relationshop between the total number of flowers the number of secondary inflorescences


Conn A, Chandrasekhar A, Rongen MV, Leyser O, Chory J, Navlakha S (2019) Network trade-offs and homeostasis in Arabidopsis shoot architectures. PLoS Comput Biol. doi: 10.1371/journal.pcbi.100732 Open Access

Lead author is Adam Conn. UK contribution from Sainsbury Laboratory, University of Cambridge. This study performed 3D scanning of 152 Arabidopsis shoot architectures to investigate how plants make trade-offs between competing objectives.


de Jong M, Tavares H, Pasam RK, Butler R, Ward S, George G, Melnyk CW, Challis R, Kover PX, Leyser O (2019) Natural variation in Arabidopsis shoot branching plasticity in response to nitrate supply affects fitness. PLoS Genet. doi: 10.1371/journal.pgen.1008366 Open Access

Lead author is Maaike de Jong. UK contribution from the Sainsbury Laboratory, University of Cambridge, the University of York and the University of Bath. This study looks at phenotypic plasticity of shoot branching in Arabidopsis diversity panels grown until different nitrate concentrations.


Molina-Contreras MJ, Paulišić S, Then C, Moreno-Romero J, Pastor-Andreu P, Morelli L, Roig-Villanova I, Jenkins H, Hallab A, Gan X, Gómez-Cadenas A, Tsiantis M, Rodriguez-Concepcion M, Martinez-Garcia JF (2019) Photoreceptor Activity Contributes to Contrasting Responses to Shade in Cardamine and Arabidopsis Seedlings. Plant Cell. doi: 10.1105/tpc.19.00275 Open Access

Lead author is Maria Jose Molina-Contreras. UK contribution from the University of Oxford. The authors looks at the response to different light conditions and how they contribute to phenotypic determination in Cardamine and Arabidopsis seedlings.


Van de Weyer AL, Monteiro F, Furzer OJ, Nishimura MT, Cevik V, Witek K, Jones JDG, Dangl JL, Weigel D, Bemm F (2019) A Species-Wide Inventory of NLR Genes and Alleles in Arabidopsis thaliana. Cell. doi: 10.1016/j.cell.2019.07.038 Open Access

Lead author is Anna-Lena Van de Weyer. UK contribution from The Sainsbury Laboratory, Norwich. Using sequence enrichment and long-read sequencing the authors present the pan-NLRome constructed from 40 Arabidopsis accessions.


Hurst CH, Wright KM, Turnbull D, Leslie K, Jones S, Hemsley PA (2019) Juxta-membrane S-acylation of plant receptor-like kinases is likely fortuitous and does not necessarily impact upon function. Sci Rep. doi: 10.1038/s41598-019-49302-x Open Access

Lead author is Charlotte Hurst. UK contribution from the James Hutton Institute and the University of Dundee. They look at the functional role of post-translational modification S-acylation with a focus on the plant pathogen perceiving receptor-like kinase FLS2.


Xiao Y, Stegmann M, Han Z, DeFalco TA, Parys K, Xu L, Belkhadir Y, Zipfel C, Chai J (2019) Mechanisms of RALF peptide perception by a heterotypic receptor complex. Nature. doi: 10.1038/s41586-019-1409-7
Lead author is Yu Xiao. UK contribution from The Sainsbury Laboratory, Norwich. This study investigates how RAPID ALKALINIZATION FACTOR (RALF) peptides induce receptor complex formation to regulate immune signaling.


Wong JEMM, Nadzieja M, Madsen LH, Bücherl CA, Dam S, Sandal NN, Couto D, Derbyshire P, Uldum-Berentsen M, Schroeder S, Schwämmle V, Nogueira FCS, Asmussen MH, Thirup S, Radutoiu S, Blaise M, Andersen KR, Menke FLH, Zipfel C, Stougaard J (2019). A Lotus japonicus cytoplasmic kinase connects Nod factor perception by the NFR5 LysM receptor to nodulation. Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1815425116
Open Access

Lead author is Jaslyn Wong. UK contribution from The Sainsbury Laboratory, University of East Anglia. This work was conducted in the legume Lotus and after a proteomic screen, the authors identified NFR5-interacting cytoplasmic kinase 4 that is involved in control of Nod factor perception.


Miller C, Wells R, McKenzie N, Trick M, Ball J, Fatihi A, Dubreucq B, Chardot T, Lepiniec L, Bevan MW (2019) Variation in expression of the HECT E3 ligase UPL3 modulates LEC2 levels, seed size and crop yield in Brassica napus. Plant Cell. doi: 10.1105/tpc.18.00577
Open Access

Lead author in Charlotte Miller. UK contribution from the John Innes Centre. Activity of the Brassica napus HECT E3 ligase gene BnaUPL3 controls seed weight per pod through degradation of LEC2, a master transcriptional regulator of seed maturation and reveals a potential target for crop improvement


Coudert Y, Novák O, Harrison CJ (2019) A KNOX-Cytokinin Regulatory Module Predates the Origin of Indeterminate Vascular Plants. Curr Biol. 2019 Aug 19;29(16):2743-2750.e5. doi: 10.1016/j.cub.2019.06.083

Lead author is Yoan Coudert. UK contribution from the University of Cambridge and University of Bristol. Class I KNOX gene activity is shown to be necessary for axis extension from an intercalary region of determinate moss shoots, in part through promotion of cytokinin biosynthesis.


Burgess SJ, Reyna-Llorens I, Stevenson SR, Singh P, Jaeger K, Hibberd JM (2019) Genome-wide transcription factor binding in leaves from C3 and C4 grasses Plant Cell.  doi: 10.1105/tpc.19.00078 Open Access

Lead author is Steven Burgess. UK contribution from University of Cambridge, The Sainsbury lab University of Cambridge, University of Leeds The authors use DNaseI-SEQ to assess the similarities and differences in transcription factor binding sites in the leaves across a set of four C3 and C4 grasses.


Harrington SA, Overend LE, Cobo N, Borrill P, Uauy C (2019) Conserved residues in the wheat (Triticum aestivum) NAM-A1 NAC domain are required for protein binding and when mutated lead to delayed peduncle and flag leaf senescence. BMC Plant Biol. doi: 10.1186/s12870-019-2022-
Lead author is Sophie Harrington. UK contributions from the John Innes Centre and University of Birmingham. The authors used a wheat TILLING resource to investigate mutrant allele with the NAC domain of the NAM-A1 transcription factor and their contribution to phenotypes in lab and field.


Jia Y, Burbidge CA, Sweetman C, Schutz E, Soole K, Jenkins C, Hancock RD, Bruning JB, Ford CM (2019) An aldo-keto reductase with 2-keto- L-gulonate reductase activity functions in L-tartaric acid biosynthesis from vitamin C in Vitis vinifera. J Biol Chem. doi: 10.1074/jbc.RA119.010196 Open Access

Lead author Yong Jia. UK contribution from the James Hutton Institute. This work conducted in grape reveals the mechanism by which an aldo-keto reductase functions in tartaric acid biosynthesis.


Perdomo JA, Degen GE, Worrall D, Carmo-Silva E (2019) Rubisco activation by wheat Rubisco activase isoform 2β is insensitive to inhibition by ADP. Biochem J. doi: 10.1042/BCJ2019011 Open Access

Lead author is Juan Alejandro Perdomo. UK contribution from Lancaster University. They show through analysis of site-directed mutations across three isoforms of wheat Rubisco activase that these isoforms have different sensitivities to ADP.


Gurrieri L, Distefano L, Pirone C, Horrer D, Seung D, Zaffagnini M, Rouhier N, Trost P, Santelia D, Sparla F (2019) The Thioredoxin-Regulated α-Amylase 3 of Arabidopsis thaliana Is a Target of S-Glutathionylation. Front Plant Sci. doi: 10.3389/fpls.2019.00993 Open Access

Lead author is Libero Gurrieri. UK contribution from John Innes Centre. The chloroplastic α-Amylases, AtAMY3 is post-translationally modified by S-glutathionylation in response to oxidative stress.


Mucha S, Heinzlmeir S, Kriechbaumer V, Strickland B, Kirchhelle C, Choudhary M, Kowalski N, Eichmann R, Hueckelhoven R, Grill E, Kuster B, Glawischnig E (2019) The formation of a camalexin-biosynthetic metabolon. Plant Cell. doi: 10.1105/tpc.19.00403 Open Access

Lead author is Stefanie Mucha. UK contribution from Oxford Brookes University and University of Warwick. The authors performed two independent untargeted co-immunoprecipitations to identify components involved in biosynthesis of the antifungal phytoalexin camalexin.


Atkinson N, Velanis CN, Wunder T, Clarke DJ, Mueller-Cajar O, McCormick AJ (2019) The pyrenoidal linker protein EPYC1 phase separates with hybrid Arabidopsis-Chlamydomonas Rubisco through interactions with the algal Rubisco small subunit. J Exp Bot. doi: 10.1093/jxb/erz275
Open Access

Lead author is Nicky Atkinson. UK contribution from the University of Edinburgh. This study uses Arabidopsis-Chlamydomonas to investigate the protein-protein interaction between Rubisco and essential pyrenoid component 1 (EPYC1).


Wightman R, Busse-Wicher M, Dupree P (2019) Correlative FLIM-confocal-Raman mapping applied to plant lignin composition and autofluorescence. Micron. doi: 10.1016/j.micron.2019.102733
Lead author Raymond Wightman. UK contribution from the Sainsbury Laboratory, University of Cambridge and the University of Cambridge. This study uses applies a novelmethod of correlative FLIM-confocal-Raman imaging to analyse lignin composition in Arabidopsis stems.


Milhinhos A, Vera-Sirera F, Blanco-Touriñán N, Mari-Carmona C, Carrió-Seguí À, Forment J, Champion C, Thamm A, Urbez C, Prescott H, Agustí J (2019) SOBIR1/EVR prevents precocious initiation of fiber differentiation during wood development through a mechanism involving BP and ERECTA. Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1807863116
Lead author is Ana Milhinho. UK contribution from the University of Oxford. The authors used GWAS in Arabidopsis to identify the SOBIR1/EVR as an important regulator of the control of secondary growth in xylem fibers.


Hartman S, Liu Z, van Veen H, Vicente J, Reinen E, Martopawiro S, Zhang H, van Dongen N, Bosman F, Bassel GW, Visser EJW, Bailey-Serres J, Theodoulou FL, Hebelstrup KH, Gibbs DJ, Holdsworth MJ, Sasidharan R, Voesenek LACJ (2019) Ethylene-mediated nitric oxide depletion pre-adapts plants to hypoxia stress. Nat Commun. doi: 10.1038/s41467-019-12045-4 Open Access

Lead author is Sjon Hartman. UK contribution from the University of Nottingham, Rothamsted Research and the University of Birmingham. This multinational collaboration looks into the relationship of how ethylene mediated nitric-oxide signaling responds to environmental signals.


Dittrich M, Mueller HM, Bauer H, Peirats-Llobet M, Rodriguez PL, Geilfus CM, Carpentier SC, Al Rasheid KAS, Kollist H, Merilo E, Herrmann J, Müller T, Ache P, Hetherington AM, Hedrich R (2019) The role of Arabidopsis ABA receptors from the PYR/PYL/RCAR family in stomatal acclimation and closure signal integration. Nat Plants. doi: 10.1038/s41477-019-0490-0
Lead author Marcus Dittrich. UK contribution from the University of Bristol. This work looks at the role of ABA signaling in stomatal responses and that the multiple ABA receptors can be modulated differentially in a stimulus-specific manner.


Villaécija-Aguilar JA, Hamon-Josse M, Carbonnel S, Kretschmar A, Schmid C, Dawid C, Bennett T, Gutjahr C (2019). SMAX1/SMXL2 regulate root and root hair development downstream of KAI2-mediated signalling in Arabidopsis. PLoS Genet. doi: 10.1371/journal.pgen.1008327 Open Access

Lead author Jose Antonio Villaécija-Aguilar. UK contribution from the University of Leeds and The Sainsbury lab, University of Cambridge. This demonstrates that KAI2 signalling through SMAX1/SMXL2 , is an important new regulator of root hair and root development in Arabidopsis.

GARNet Research Roundup: August 16th 2019

This holiday-time edition of the GARNet research roundup begins with two papers that include the late Ian Moore from the University of Oxford as a co-author. The first looks at the role of RAB-A5c in the control of cellular growth anisotropy whilst the second characterises the Transport Protein Particle II (TRAPPII) complex.

The third paper is a UK-wide collaboration that assesses the role of UVA signaling on stomatal development. Next is a paper from Cambridge and the JIC that has identified the TAF4b protein as a novel regulator of meiotic crossovers.

The fifth paper is from the University of York and characterizes a role for cis-12-oxo-phytodienoic acid (OPDA) during seed germination.

The next three papers feature scientists from the University of Leeds in research that investigates 1, a peroxisomal ABC transporter; 2, the role of LRR-RLKs in plasmodesmata development and 3, the cell wall characteristics of banana and mango fruit.

The ninth paper is from the University of Edinburgh and investigates the role of S-nitrosylation in the control of SUMO conjugation.

The next two papers include Steve Penfield at the JIC as a corresponding author; the first looks at the role of endosperm-expressed transcriptional factors during seed dormancy and the second, in collaboration with researchers at the University of Warwick, identifies novel QTLs involved in seed dormancy.

The penultimate study is from Lancaster and presents a surprising outcome resulting from the overexpression of the wheat CA1Pase gene. The final paper includes Alison Tidy and Zoe Wilson from University of Nottingham as co-authors on a study that looks at male fertility in Arabidopsis.


Kirchhelle C, Garcia-Gonzalez D, Irani NG, Jérusalem A, Moore I (2019) Two mechanisms regulate directional cell growth in Arabidopsis lateral roots. Elife. pii: e47988. doi: 10.7554/eLife.47988

Open Access

Charlotte Kirchhelle leads this work that was conducted in the lab of the late Ian Moore at the University of Oxford. She investigates the role of the plant-specific small GTPase RAB-A5c during growth anisotropy in lateral roots, which involves coordinated orientations of cellulose microfibrils (CMFs) and by cortical microtubules (CMTs). They identify RAB-A5c dependent and independent mechanisms to control cellular growth anisotropy in this growing tissue.

From https://elifesciences.org/articles/47988

Kalde M, Elliott L, Ravikumar R, Rybak K, Altmann M, Klaeger S, Wiese C, Abele M, Al B, Kalbfuß N, Qi X, Steiner A, Meng C, Zheng H, Kuster B, Falter-Braun P, Ludwig C, Moore I, Assaad FF (2019) Interactions between Transport Protein Particle (TRAPP) complexes and Rab GTPases in Arabidopsis. Plant J. doi: 10.1111/tpj.14442

This German-led study includes Monika Kalde from the University of Oxford as first author as well Ian Moore as co-author. They characterize the components and function of the Transport Protein Particle II (TRAPPII) complex. TRAPPII plays multiple roles in intra-cellular transport and this study identified 13 subunits, including several that were previously uncharacterised.


Isner JC, Olteanu VA, Hetherington AJ, Coupel-Ledru A, Sun P, Pridgeon AJ, Jones GS, Oates M, Williams TA, Maathuis FJM, Kift R, Webb AR, Gough J, Franklin KA, Hetherington AM (2019). Short- and Long-Term Effects of UVA on Arabidopsis Are Mediated by a Novel cGMP Phosphodiesterase. Curr Biol.29(15):2580-2585.e4. doi: 10.1016/j.cub.2019.06.071

Open Access

Jean-Charles Isner is the first author on this collaboration between labs in Bristol, York, Oxford and Cambridge. They show that UVA radiation (which represents 95% of the UV radiation reaching earth) inhibits stomatal opening through a process that involves a reduction in the cytosolic level of cGMP. The AtCN-PDE1 gene (a cGMP-activated phosphodiesterase) is needed to decrease cGMP levels in Arabidopsis. This response is present across the tree of life except in metazoans. They show AtCN-PDE1 is needed for the UVA response and that prolonged UVA exposure causes increased growth yet reduced water use efficiency.


Lawrence EJ, Gao H, Tock AJ, Lambing C, Blackwell AR, Feng X, Henderson IR (2019) Natural Variation in TBP-ASSOCIATED FACTOR 4b Controls Meiotic Crossover and Germline Transcription in Arabidopsis. Curr Biol. pii: S0960-9822(19)30844-9. doi: 10.1016/j.cub.2019.06.084

Open Access

This work from Ian Henderson’s lab in Cambridge and Xiaoqi Feng’s lab at the JIC is led by Emma Lawrence and isolates a novel modifier of meiotic crossover frequency, TBP-ASSOCIATED FACTOR 4b (TAF4b), which encodes a subunit of the RNA polymerase II general transcription factor TFIID. They show TAF4b expression is enriched in meiocytes, compared to the more general expression of its paralog TAF4. Ultimately they reveal TAF4b drives a novel mode of meiotic recombination control through its activity as a general transcription factor.


Barros-Galvão T, Dave A, Cole A, Harvey D, Langer S, Larson TR, Vaistij FE, Graham IA (2019) cis-12-oxo-phytodienoic acid represses Arabidopsis thaliana seed germination in shade light conditions. J Exp Bot. pii: erz337. doi: 10.1093/jxb/erz337

Open Access

Thiago Barros-Galvão is first author on this study from Ian Graham’s lab at the University of York. They investigate how the jasmonic acid pre-cursor cis-12-oxo-phytodienoic acid (OPDA) contributes to control of seed germination, particularly under shade conditions. OPDA acts through the activity of the transcription factor MOTHER-OF-FT-AND-TFL1 (MFT).

From https://academic.oup.com/jxb/advance-article/doi/10.1093/jxb/erz337/5536641

Carrier DJ, van Roermund CWT, Schaedler TA, Rong HL, IJlst L, Wanders RJA, Baldwin SA, Waterham HR, Theodoulou FL, Baker A (2019) Mutagenesis separates ATPase and thioesterase activities of the peroxisomal ABC transporter, Comatose. Sci Rep. 9(1):10502. doi: 10.1038/s41598-019-46685-9

Open Access

Alison Baker at the University of Leeds is the corresponding author of this UK, Dutch collaboration that includes David Carrier as first author. They characterise the peroxisomal ABC transporter, Comatose (CTS) through mutagenesis of key residues responsible for the proteins intrinsic acyl-CoA thioesterase (ACOT) activity. Ultimately they show that ACOT activity depends of endogenous ATPase activity but that these activities could be functional separated by mutagenesis of key residues.


Grison M, Kirk P, Brault M, Wu XN, Schulze WX, Benitez-Alfonso Y, Immel F, Bayer EMF (2019). Plasma membrane-associated receptor like kinases relocalize to plasmodesmata in response to osmotic stress. Plant Physiol. pii: pp.00473.2019. doi: 10.1104/pp.19.00473

Open Access

GARNet advisory committee member Yoselin Benitez-Alfonso and members of her research group are co-authors on the next two studies. This work is led by Magali Grison in Emmanuelle Bayer’s lab in Bordeaux. They show that the PM-localised Leucine-Rich-Repeat Receptor-Like-Kinases (LRR-RLKs), QSK1 and IMK2 relocate and cluster to the plasmodesmata under osmotic stress conditions. Through a variety of assays that focuses on QSK1 the authors show that reorganisation of RLKs can be important for the regulation of callose deposition at plasmodesmata and under osmotic stress this can have a functional effect on lateral root development.


Rongkaumpan G, Amsbury S, Andablo-Reyes E, Linford H, Connell S, Knox JP, Sarkar A, Benitez-Alfonso Y, Orfila C (2019) Cell Wall Polymer Composition and Spatial Distribution in Ripe Banana and Mango Fruit: Implications for Cell Adhesion and Texture Perception. Front Plant Sci. 10:858. doi: 10.3389/fpls.2019.00858

Open Access

Ganittha Rongkaumpan is first author on this interdisciplinary collaborative research from multiple departments at the University of Leeds. They characterise the composition of the cell wall in two fruits, banana and mango, which soften during ripening. The authors compared structural information, obtained using Atomic Force Microscopy and biochemical analysis, with data from rheology and tribology assays to understand why these fruits feel different in the mouth during ingestion.


Skelly MJ, Malik SI, Le Bihan T, Bo Y, Jiang J, Spoel SH, Loake GJ (2019) A role for S-nitrosylation of the SUMO-conjugating enzyme SCE1 in plant immunity Proc Natl Acad Sci U S A. pii: 201900052. doi: 10.1073/pnas.1900052116

Michael Skelly from the University of Edinburgh is the lead author of this study from the labs of Gary Loake and GARNet chairman Steven Spoel. They investigate the mechanism through which nitric oxide signaling after pathogen recognition stimulates inhibitory S-nitrosylation of the Arabidopsis SUMO E2 enzyme, SCE1. S-nitrosylation occurs on the evolutionary conserved Cys139 of SCE1 and they investigate the wider significant of this residue in the control of immune responses across eukaryotes.


MacGregor DR, Zhang N, Iwasaki M, Chen M, Dave A, Lopez-Molina L, Penfield S (2019) ICE1 and ZOU determine the depth of primary seed dormancy in Arabidopsis independently of their role in endosperm development. Plant J. 98(2):277-290. doi: 10.1111/tpj.14211

Open Access

Dana MacGregor (now at Rothamsted Research) leads this work from the lab of Steve Penfield at the JIC that investigates the extent of control on depth of primary dormancy that is mediated by the endosperm-expressed transcription factors ZHOUPI (ZOU) and INDUCER OF CBF EXPRESSION1 (ICE1). These effects are additive and independent of their role in endosperm development since the dormancy defect in ice1 and zou mutants can be ameliorated without altering seed morphology. They show that ICE1 acts primarily through control of ABA INSENSITIVE 3 (ABI3).


Footitt S, Walley PG, Lynn JR, Hambidge AJ, Penfield S, Finch-Savage WE (2019) Trait analysis reveals DOG1 determines initial depth of seed dormancy, but not changes during dormancy cycling that result in seedling emergence timing. New Phytol. doi: 10.1111/nph.16081

This research is a collaboration between the John Innes Centre and the Universities Liverpool and Warwick, from which Steven Footitt is first author. They used two Arabidopsis ecotypes that have differences in the timing of seedling emergence to identify new QTLs involved in depth of seed dormancy and Seedling Emergence Timing (SET). They revealed that DOG1 is important for determining depth of dormancy. In addition they identified three new SET QTLs, which are each physically close to DOG1, that play a role in the control of SET in the field.


Lobo AKM, Orr D, Gutierrez MO, Andralojc J, Sparks C, Parry MAJ, Carmo-Silva E (2019) Overexpression of ca1pase decreases Rubisco abundance and grain yield in wheat. Plant Physiol. pii: pp.00693.2019. doi: 10.1104/pp.19.00693

Open Access

This research from Lancaster Environmental Centre and their Brazilian collaborators is led by Ana Karla Lobo and demonstrates that overexpression of 2-carboxy-D-arabinitol-1-phosphate phosphatase (CA1Pase) in wheat causes a reduction in above ground biomass and compromises wheat grain yields. As CA1Pase is involved in removing inhibitors of Rubisco activity this result is contrary to the anticipated outcome. This suggests that Rubisco inhibitors might actually protect enzyme activity, thus maintaining the number of active sites that the enzyme is able to support.


Zhao SQ, Li WC, Zhang Y, Tidy AC, Wilson ZA (2019) Knockdown of Arabidopsis ROOT UVB SENSITIVE4 Disrupts Anther Dehiscence by Suppressing Secondary Thickening in the Endothecium. Plant Cell Physiol. doi: 10.1093/pcp/pcz127

Shu-Qing Zhao is the lead author on this China-UK collaboration that includes Alison Tidy and Zoe Wilson from the University of Nottingham. They show that using an artificial microRNA to reduce levels of the RUS4 gene in Arabidopsis causes a decline in male fertility. They perform a detailed analysis of the RUS4 expression module and how it impacts fertility.

GARNet Research Roundup: June 12th 2019

In another big edition of the GARNet Research Roundup we cover many different areas of research that utilise a varied group of experimental organisms!

The first paper from the Feng lab at the John Innes Centre performs an assessment of the factors influencing heterochromatin activity in sperm companion cells. Second is work from the JIC and Cardiff University that looks at the role of an auxin minima during fruit valve margin differentiation.

The next two papers have authors from Edinburgh. Firstly the McCormick lab has developed a stereo-based 3D imaging system for plants while Steven Spoel is a co-author on a study that looks at the pathogen responsive gene NPR1.

Coming from across the M8 is a paper from the Christie lab in Glasgow that looks into using phototropin genes as potential targets for crop improvement.

The next paper is from Oxford Brookes University where they visualise the movement of protein nanodomain clusters within the plasma membrane. Elsewhere in Oxford is a paper from the van der Hoorn group that characterises the effect of a novel triazine herbicide.

Two papers from the University of Durham also identify and characterise the role of novel herbicides, in this case on the activity of inositol phosphorylceramide synthases.

The final five papers feature research that each use different experimental organisms. Firstly a paper from the Earlham Institute uses delayed fluorescence to investigate the circadian clock in wheat and OSR. Second is a paper from Warwick that assesses the role of nodulation during nitrogen uptake in Medicago. The next paper features the Yant lab at University of Nottingham looks at growth of two species of Arabidopsis in challenging environments.

The penultimate paper includes authors from the University of Oxford and provides a detailed analysis of the factors controlling leaf shape in Cardamine and Arabidopsis thaliana. The final paper uses the imaging facility at the Hounsfield facility in Nottingham to image the roots of date palms.


He S, Vickers M, Zhang J, Feng X (2019) Natural depletion of H1 in sex cells causes DNA demethylation, heterochromatin decondensation and transposon activation. Elife. doi: 10.7554/eLife.42530

Open Access

Lead author on his paper is Shengbo He from Xiaoqi Feng’s lab at the John Innes Centre. This work looks at activation of Transposable elements (TEs) in the sperm companion cell of Arabidopsis. This is catalyzed by the DEMETER-catalyzed DNA demethylation in regions depleted of histone H1, demonstrating a key role for H1 in determining heterochromatin activity.

https://elifesciences.org/articles/42530

Li XR, Vroomans RMA, Fox S, Grieneisen VA, Østergaard L, Marée AFM (2019) Systems Biology Approach Pinpoints Minimum Requirements for Auxin Distribution during Fruit Opening. Mol Plant. doi: 10.1016/j.molp.2019.05.003

Open Access

Xin-Ran Li and Renske Vroomans are co-lead authors on this work from the Ostergaard, Grieneisen and Maree labs from the John Innes Centre and (now) Cardiff University.They look at the role of an auxin minima in the control of valve margin differentiation in Arabidopsis fruit. They used a cycle of experimental-modeling to develop a model that predicts the maturation of the auxin minimum to ensure timely fruit opening and seed dispersal.


Bernotas G, Scorza LCT, Hansen MF, Hales IJ, Halliday KJ, Smith LN, Smith ML, McCormick AJ (2019) A photometric stereo-based 3D imaging system using computer vision and deep learning for tracking plant growth. Gigascience. doi: 10.1093/gigascience/giz056

Open Access

Gytis Bernotas from UWE and Livia Scorza from the McCormick lab at the University of Edinburgh lead this work that is the result of a 2+ year collaboration with the Melvyn Smith and others at the Computer Machine Vision (CMV) facility at UWE. The authors have developed hardware and software (including a deep neural network) to automate the 3D imaging and segmentation of rosettes and individual leaves using a photometric stereo approach.

https://academic.oup.com/gigascience/article/8/5/giz056/5498634

Chen J, Mohan R, Zhang Y, Li M, Chen H, Palmer IA, Chang M, Qi G, Spoel SH, Mengiste T, Wang D, Liu F, Fu ZQ (2019) NPR1 promotes its own and target gene expression in plant defense by recruiting CDK8. Plant Physiol. doi: 10.1104/pp.19.00124

GARNet chairman Steven Spoel is a co-author on this US-led study with Jian Chen as lead author. The paper investigates the interacting partners of NPR1 (NONEXPRESSER OF PR GENES 1), which is a master regulator of salicyclic signaling and therefore an important regulation of plant defense response.


Hart JE, Sullivan S, Hermanowicz P, Petersen J, Diaz-Ramos LA, Hoey DJ, Łabuz J, Christie JM (2019) Engineering the phototropin photocycle improves photoreceptor performance and plant biomass production. Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1902915116

Open Access

Jaynee Hart is first author on this research from Christie lab at the University of Glasgow in which they target the phototropin blue light receptor as a candidate for crop improvement. They showed plants that engineered to have a slow-photocycling version of PHOT1 or PHOT2 had increased biomass under low light conditions, due to their increased sensitivity to low light.


McKenna JF, Rolfe DJ, Webb SED, Tolmie AF, Botchway SW, Martin-Fernandez ML, Hawes C, Runions J (2019) The cell wall regulates dynamics and size of plasma-membrane nanodomains in Arabidopsis. Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1819077116

Open Access

Joe McKenna from Oxford Brookes University leads this work that takes advantage of their superb imaging facilities to assess the dynamic regulation of specific protein clusters in the Arabidopsis plasma membrane. They show that the cytoskeleton (both actin and microtubule) and the cell wall play roles in the control of intra-PM moment of the pathogen receptor FLS2 and the auxin transporter PIN3.

https://www.pnas.org/content/early/2019/06/07/1819077116

Morimoto K, Cole KS, Kourelis J, Witt CH, Brown D, Krahn D, Stegmann M, Kaschani F, Kaiser M, Burton J, Mohammed S, Yamaguchi-Shinozaki K, Weerapana E, van der Hoorn RAL (2019) Triazine probes targeting ascorbate peroxidases in plants. Plant Physiol. doi: 10.1104/pp.19.00481

Open Access

Kyoko Morimoto is first author on this UK-German-Japanese collaboration led from the lab of GARNet committee member Renier van der Hoorn. They characterise the herbicidal effect of the small 1,3,5-triazine KSC-3 on ascorbate peroxidases (APXs) across a range of plant species.


Pinneh EC, Stoppel R, Knight H, Knight MR, Steel PG, Denny PW (2019) Expression levels of inositol phosphorylceramide synthase modulate plant responses to biotic and abiotic stress in Arabidopsis thaliana. PLoS One. doi: 10.1371/journal.pone.0217087

Open Access

Pinneh EC, Mina JG, Stark MJR, Lindell SD, Luemmen P, Knight MR, Steel PG, Denny PW (2019) The identification of small molecule inhibitors of the plant inositol phosphorylceramide synthase which demonstrate herbicidal activity. Sci Rep. doi: 10.1038/s41598-019-44544-1

Open Access

Elizabeth Pinneh leads these two papers from the Denny lab in Durham. In the first paper they use RNAseq data and analysis of overexpression transgenic lines to define the role of inositol phosphorylceramide synthase (IPCS) during abiotic and biotic stress responses.

Secondly they screened a panel of 11000 compounds for their activity against the AtIPCS2 in a yeast two-hybrid assay. Successful hits from the screen were confirmed with in vitro enzyme assays and in planta against Arabidopsis.


Rees H, Duncan S, Gould P, Wells R, Greenwood M, Brabbs T, Hall A (2019) A high-throughput delayed fluorescence method reveals underlying differences in the control of circadian rhythms in Triticum aestivum and Brassica napus. Plant Methods. doi: 10.1186/s13007-019-0436-6

Open Access

Hannah Rees from Anthony Hall’s lab at the Earlham Institute leads this methods paper that introduces the use of delayed fluorescence to investigate the circadian rhythms in wheat and oil seed rape.

https://plantmethods.biomedcentral.com/articles/10.1186/s13007-019-0436-6

Lagunas B, Achom M, Bonyadi-Pour R, Pardal AJ, Richmond BL, Sergaki C, Vázquez S, Schäfer P, Ott S, Hammond J, Gifford ML (2019) Regulation of Resource Partitioning Coordinates Nitrogen and Rhizobia Responses and Autoregulation of Nodulation in Medicago truncatula. Mol Plant. doi: 10.1016/j.molp.2019.03.014

Open Access

Beatriz Lagunas is lead author on this paper from the University of Warwick that investigates the role of nodulation in actual nitrogen uptake by the roots of Medicago truncatula. They use integrated molecular and phenotypic analysis to determine that the respond to nitrogen flux are processed on a whole plant level through multiple developmental processes.

https://www.cell.com/molecular-plant/fulltext/S1674-2052(19)30127-3?

Preite V, Sailer C, Syllwasschy L, Bray S, Ahmadi H, Krämer U, Yant L (2019) Convergent evolution in Arabidopsis halleri and Arabidopsis arenosa on calamine metalliferous soils Philos Trans R Soc Lond B Biol Sci. doi: 10.1098/rstb.2018.0243

Open Access

Veronica Preite is first author on this UK-German collaboration led by Ute Kraemer and Levi Yant in Nottingham. They performed whole genome resequenced of 64 individuals of two Arabidopsis species that grow on calamine metalliferous sites (which have toxic levels of the zinc and cadmium). They revealed a modest amount of gene and network convergence in plants that have colonised these challenging environments.


Kierzkowski D, Runions A, Vuolo F, Strauss S, Lymbouridou R, Routier-Kierzkowska AL, Wilson-Sánchez D, Jenke H, Galinha C, Mosca G, Zhang Z, Canales C, Dello Ioio R, Huijser P, Smith RS, Tsiantis M (2019) A Growth-Based Framework for Leaf Shape Development and Diversity. doi: 10.1016/j.cell.2019.05.011

Open Access

Claudia Canales and Carla Galinha from Oxford are co-authors on this German-led study from Miltos Tsiantis’ lab that performs a detailed dissection of the growth parameters that control differences in leaf-shape in Cardamine and Arabidopsis. They show critical roles for the SHOOTMERISTEMLESS and REDUCED COMPLEXITY homeobox proteins to define differences in shape determination.


Xiao T, Raygoza AA, Pérez JC, Kirschner G, Deng Y, Atkinson B, Sturrock C, Lube V, Wang JY, Lubineau G, Al-Babili S, Ramírez LAC, Bennett MJ, Blilou I (2019) Emergent Protective Organogenesis in Date Palms: A Morpho-devo-dynamic Adaptive Strategy During Early Development. Plant Cell. doi: 10.1105/tpc.19.00008

Open Access

Members of the Hounsfield CT Imaging Facility 
at the University of Nottingham are co-authors on this paper that is led by Tingting Xiao from KAUST in Saudi Arabia. The paper takes a detailed look at root morphology in Date Palm.

GARNet Research Roundup: May 27th 2019

This bumper edition of the GARNet research roundup begins with a set of papers from the John Innes Centre. Anne Osbourn’s group is involved with two papers; firstly they discover how altering metabolic networks in the Arabidopsis root can cause changes in the associated microbiota. Second they characterise the role of a light-induced transcription factor in Artemisia. Next Caroline Dean’s group leads a global consortium that investigates the role of liquid-liquid phase separation in the formation of nuclear bodies. The final paper from the JIC is from Philippa Borrill and Cristobal Uauy, in which they identify novel transcription factors in wheat.

The fourth paper is led by Peter Etchells at Durham and characterises receptor kinase activity involved in vascular patterning in Arabidopsis.

The next two papers focus on stomatal patterning; firstly Julie Gray’s group at Sheffield looks at the stomatal responses to long-term pathogen infections. The second paper is from Glasgow and describes improvements in the OnGuard2 software, which models the factors controlling stomatal density.

Jose Gutierrez-Marcos is a co-author on a paper that uses FACS/ATAC-seq to define chromatin changes within cells of the shoot apical meristem. Richard Harrison leads the next paper that is also method-focused; describing use of CRISPR-Cas9 gene editing in Strawberry.

Andrew Miller at the University of Edinburgh is the corresponding author of the penultimate paper, which presents a whole-life-cycle, multi-model Framework that links many aspects of the Arabidopsis life cycle. The final paper is Seth Davies’s group at York and investigates the role of sucrose in the control of the circadian clock.


Huang AC, Jiang T, Liu YX, Bai YC, Reed J, Qu B, Goossens A, Nützmann HW, Bai Y, Osbourn A (2019) A specialized metabolic network selectively modulates Arabidopsis root microbiota. Science. doi: 10.1126/science.aau6389

Ancheng Huang and Ting Jiang are first authors on this UK, Chinese and Belgian collaboration led by Anne Osbourn at the John Innes Centre. They reconstitute three biosynthesic pathways in the Arabidopsis roots and show how this affects the associated microbiota.


Hao X, Zhong Y, Nützmann HW, Fu X, Yan T, Shen Q, Chen M, Ma Y, Zhao J, Osbourn A, Li L, Tang K (2019) Light-induced artemisinin biosynthesis is regulated by the bZIP transcription factor AaHY5 in Artemisia annua. Plant Cell Physiol. doi: 10.1093/pcp/pcz084

Anne Osbourn is a co-author on this Chinese-led study that has identified that the basic leucine zipper transcription factor (TF) AaHY5 regulated of light-induced biosynthesis of artemisinin in Artemisia annua.


Fang X, Wang L, Ishikawa R, Li Y, Fiedler M, Liu F, Calder G, Rowan B, Weigel D, Li P, Dean C (2019) Arabidopsis FLL2 promotes liquid-liquid phase separation of polyadenylation complexes. Nature. doi: 10.1038/s41586-019-1165-8

Xiaofeng Fang, Liang Wang and Ryo Ishikawa are first authors of this UK, German and Chinese collaboration led by Caroline Dean’s lab at the John Innes Centre. They characterise the molecular factors that are required for the formation of nuclear bodies through liquid-liquid phase separation (PDF). These proteins are the Arabidopsis RNA-binding protein FCA and the coiled-coil protein FLL2.

From https://www.nature.com/articles/s41586-019-1165-8

Borrill P, Harrington SA, Simmonds J, Uauy C (2019) Identification of transcription factors regulating senescence in wheat through gene regulatory network modelling. Plant Physiol. doi: 10.1104/pp.19.00380

Open Access

Philippa Borrill, now a faculty member at the University of Birmingham, conducted this work with Cristobal Uauy at the John Innes Centre. They have developed a range of research tools for use in wheat and this paper describes the identification of novel transcription factors involved in senescence.


Wang N, Bagdassarian KS, Doherty RE, Kroon JT, Connor KA, Wang XY, Wang W, Jermyn IH, Turner SR, Etchells JP (2019) Organ-specific genetic interactions between paralogues of the PXY and ER receptor kinases enforce radial patterning in Arabidopsis vascular tissue. Development. doi: 10.1242/dev.177105

Ning Wang works with Peter Etchells at Durham University where they have characterised the interactions between the receptor kinase gene families that regulate radial patterning in the development of vascular tissue.


Dutton C, Hõrak H, Hepworth C, Mitchell A, Ton J, Hunt L, Gray JE (2019) Bacterial infection systemically suppresses stomatal density. Plant Cell Environ. doi: 10.1111/pce.13570

Christian Dutton leads this work conducted at the University of Sheffield. They have investigated the longer-term systemic response to the presence of pathogens that involves reducing stomatal density. This process is mediated via salicylic acid signaling and slows disease progression.

From https://onlinelibrary.wiley.com/doi/abs/10.1111/pce.13570

Jezek M, Hills A, Blatt MR, Lew VL (2019) A constraint-relaxation-recovery mechanism for stomatal dynamics. Plant Cell Environ. doi: 10.1111/pce.13568

Mareike Jezek leads this work from the University of Glasgow in which they have updated the OnGuard2 modelling software that has demonstrated substantial predictive power to describe stomatal dynamics. Their improvements allow for the development of models that are more similar to in vivo observations.


Frerichs A, Engelhorn J, Altmüller J, Gutierrez-Marcos J, Werr W (2019) Specific chromatin changes mark lateral organ founder cells in the Arabidopsis thaliana inflorescence meristem. J Exp Bot. doi: 10.1093/jxb/erz181

Jose Gutierrez-Marcos from the University of Warwick is a co-author on this German study led by Anneke Frerichs in which they analysed the chromatin state of lateral organ founder cells (LOFCs) in the peripheral zone of the Arabidopsis inflorescence meristem in wildtype and apetala1-1 cauliflower-1 double mutants. Importantly they showed that the combined application of FACS/ATAC-seq is able to detect chromatin changes in a cell-type specific manner.


Wilson FM, Harrison K, Armitage AD, Simkin AJ, Harrison RJ (2019) CRISPR/Cas9-mediated mutagenesis of phytoene desaturase in diploid and octoploid strawberry. Plant Methods. doi: 10.1186/s13007-019-0428-6. eCollection 2019

Open Access

This paper is lead by Fiona Wilson at NIAB-EMR in which they present their methods to undertake gene editing in the challenging experimental system of diploid and octoploid strawberries.

From https://plantmethods.biomedcentral.com/articles/10.1186/s13007-019-0428-6

Zardilis A, Hume A, Millar AJ (2019) A multi-model framework for the Arabidopsis life cycle. J Exp Bot. doi: 10.1093/jxb/ery394

Open Access

Argyris Zardilis conducted this modeling-focussed research at University of Edinburgh. The authors present a whole-life-cycle, multi-model Framework that links vegetative, inflorescence as fruit growth as well as seed dormancy in Arabidopsis. This Framework allows the authors to simulate at the population level in various genotype × environment scenarios.

From https://academic.oup.com/jxb/article/70/9/2463/5336616

Philippou K, Ronald J, Sánchez-Villarreal A, Davis AM, Davis SJ (2019) Physiological and Genetic Dissection of Sucrose Inputs to the Arabidopsis thaliana Circadian System. Genes (Basel). doi: 10.3390/genes10050334

Open Access

Koumis Philippou from Seth Davis’ research group the University of York leads this work that investigates the role of sucrose into the function of the circadian clock.

GARNet Research Roundup: April 29th 2019

This edition of the GARNet research roundup features fundamental plant science research conducted in a range of experimental organisms. Firstly Liam Dolan’s lab in Oxford looks at the function of bHLHs proteins in cell differentiation across land plant evolution. Secondly Anthony Hall’s group at the Earlham Institute have identified a novel RecQ helicase involved in work exclusively conducted in wheat. Thirdly researchers from Nottingham work with Arabidopsis to characterise an EXPANSIN protein essential for lateral root development.

The fourth paper is the first of two that look at germination and uses a new model, Aethionema arabicum, to study the role of light in seed dormancy. This work includes research from Royal Holloway. The second ‘dormancy’ paper is from Peter Eastmond’s lab at Rothamsted and further characterises the DOG1 gene in Arabidopsis. The penultimate paper includes co-authors from Warwick and Leeds and introduces a novel chemical inhibitor of auxin transport. The final paper from researchers in Birmingham introduces the 3DCellAtlas Meristem, a powerful tool for cellular annotation of the shoot apical meristem.


Bonnot C, Hetherington AJ, Champion C, Breuninger H, Kelly S, Dolan L (2019) Neofunctionalisation of basic helix loop helix proteins occurred when embryophytes colonised the land. New Phytol. doi: 10.1111/nph.15829 https://nph.onlinelibrary.wiley.com/doi/abs/10.1111/nph.15829

Clemence Bonnot is lead author on this study from Liam Dolan’s lab at the University of Oxford in which the authors assess the role of ROOT HAIR DEFECTIVE SIX-LIKE (RSL) genes during evolution of plant development. They look at the function of a member of this bHLH transcription factor family called CbbHLHVIII identified in the charophyceaen alga Chara braunii. This gene is expressed at specific morphologically important regions in the algae and cannot rescue the function of related RSL genes in Marchantia or Arabidopsis. This suggests that the function of RSL proteins in cell differentiation has evolved by neofunctionalisation through land plant lineages.


Gardiner LJ, Wingen LU, Bailey P, Joynson R, Brabbs T, Wright J, Higgins JD, Hall N, Griffiths S, Clavijo BJ, Hall A (2019) Analysis of the recombination landscape of hexaploid bread wheat reveals genes controlling recombination and gene conversion frequency. Genome Biol. 20(1):69. doi: 10.1186/s13059-019-1675-6 https://genomebiology.biomedcentral.com/articles/10.1186/s13059-019-1675-6

Open Access

Laura Gardiner and Anthony Hall lead this work that was conducted at the Earlham Institute and uses a bespoke set of bioinformatic tools that allow fundamental questions to be asked in hexaploid wheat. They looked at crossover and gene conversion frequencies in 13 recombinant inbred mapping populations and were able to identity an important QTL and confirm functionality for a novel RecQ helicase gene. This gene does not exist in Arabidopsis and therefore this discovery-motivated research needed to be conducted in wheat. They hope that this identification will provide future opportunities to tackle the challenge of linkage drag when attempting to develop new crops varieties.


Ramakrishna P, Ruiz Duarte P, Rance GA, Schubert M, Vordermaier V, Vu LD, Murphy E, Vilches Barro A, Swarup K, Moirangthem K, Jørgensen B, van de Cotte B, Goh T, Lin Z, Voβ U, Beeckman T, Bennett MJ, Gevaert K, Maizel A, De Smet I (2019) EXPANSIN A1-mediated radial swelling of pericycle cells positions anticlinal cell divisions during lateral root initiation. Proc Natl Acad Sci U S A. 2019 Apr 3. pii: 201820882. doi: 10.1073/pnas.1820882116 https://www.pnas.org/content/early/2019/04/02/1820882116.long

Open Access

This pan-European study is led by Priya Ramakrishna at the University of Nottingham and includes co-authors from the UK, Belgium, Germany and Denmark. The authors look at the lateral root development and characterise the function of the EXPANSIN A1 protein. This protein influences the physical changes in the cell wall that are needed to enable the asymmetry cell divisions that define the location of a new lateral root. Plants lacking EXPA1 function do not properly form lateral roots and are unable to correctly respond to an inductive auxin signal. This clearly demonstrates an important requirement for the activity of genes that transmit cell signals into the physical relationships that exist between cells.

https://plantmethods.biomedcentral.com/articles/10.1186/s13007-019-0413-0

Mérai Z, Graeber K, Wilhelmsson P, Ullrich KK, Arshad W, Grosche C, Tarkowská D, Turečková V, Strnad M, Rensing SA, Leubner-Metzger G, Scheid OM (2019) Aethionema arabicum: a novel model plant to study the light control of seed germination. J Exp Bot. pii: erz146. doi: 10.1093/jxb/erz146

https://academic.oup.com/jxb/advance-article/doi/10.1093/jxb/erz146/5428144

Open Access

This paper includes authors from the UK, Germany, Austria and the Czech Republic including Kai Graeber and Gerhard Leubner-Metzger at Royal Holloway. They introduce the Brassica Aethionema arabicum as a new model to investigate the mechanism of germination inhibition by light as they have identified accessions that are either light-sensitive or light-neutral. In contrast germination in Arabidopsis is stimulated by light. Transcriptome analysis of Aethionema arabicum accessions reveal expression changes in key hormone-regulated genes. Overall they show that largely the same module of molecular components are involved in control of of seed dormancy irrespective of the effect of light on germination. Therefore any phenotypic changes likely result from changes in the activity organisms-specific of these genes.

https://academic.oup.com/jxb/advance-article/doi/10.1093/jxb/erz146/5428144

Bryant FM, Hughes D, Hassani-Pak K, Eastmond PJ (2019) Basic LEUCINE ZIPPER TRANSCRIPTION FACTOR 67 transactivates DELAY OF GERMINATION 1 to establish primary seed dormancy in Arabidopsis. Plant Cell. pii: tpc.00892.2018. doi: 10.1105/tpc.18.00892 http://www.plantcell.org/content/early/2019/04/08/tpc.18.00892.long

Open Access

http://www.plantcell.org/content/early/2019/04/08/tpc.18.00892.long

Fiona Bryant is lead author on this research from Rothamsted Research that investigates the factors that control expression of the DOG1 gene, which is a key regulator of seed dormancy. They show that LEUCINE ZIPPER TRANSCRIPTION FACTOR67 (bZIP67) regulates DOG1 expression and have uncovered a mechanism that describes the temperature-dependent regulation of DOG1 expression. Finally they identity a molecular change that explains known allelic difference in DOG1 function, which informs different levels of dormancy in different accessions.


Oochi A, Hajny J, Fukui K, Nakao Y, Gallei M, Quareshy M, Takahashi K, Kinoshita T, Harborough SR, Kepinski S, Kasahara H, Napier RM, Friml J, Hayashi KI (2019) Pinstatic acid promotes auxin transport by inhibiting PIN internalization. Plant Physiol. 2019 Apr 1. pii: pp.00201.2019. doi: 10.1104/pp.19.00201 http://www.plantphysiol.org/content/early/2019/04/01/pp.19.00201.long

Open Access

http://www.plantphysiol.org/content/early/2019/04/01/pp.19.00201.long

This Japanese-led study includes co-authors from the Universities of Warwick and Leeds and describes the identification of a novel positive chemical modulator of auxin cellular efflux. This aptly named PInStatic Acid (PISA) prevents PIN protein internalization yet does not impact the SCFTIR1/AFB signaling cascade. Therefore the authors hope that PISA will be a useful tool for unpicking the cellular mechanisms that control auxin transport.


Montenegro-Johnson T, Strauss S, Jackson MDB, Walker L, Smith RS, Bassel GW. (2019) 3D Cell Atlas Meristem: a tool for the global cellular annotation of shoot apical meristems. Plant Methods. 15:33. doi: 10.1186/s13007-019-0413-0

https://plantmethods.biomedcentral.com/articles/10.1186/s13007-019-0413-0

Open Access

Thomas Montenegro-Johnson, Soeren Strauss, Matthew Jackson and Liam Walker lead this methods paper that was prepared following research that took place at the University of Birmingham and the Max Planck Institute for Plant Breeding Research in Cologne. They describe the 3DCellAtlas Meristem, a tool allows the complete cellular annotation of cells within a shoot apical meristem (SAM), which they have successfully tested in both Arabidopsis and tomato. The authors state that ‘this provides a rapid and robust means to perform comprehensive cellular annotation of SAMs and digital single cell analyses, including cell geometry and gene expression’.

https://plantmethods.biomedcentral.com/articles/10.1186/s13007-019-0413-0
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