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

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.

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.

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.

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.

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).

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.

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.

GARNet Research Roundup: March 13th 2020

This edition of the GARNet Research Roundup begins with research from Durham University that links environmental sensing, SUMOylation and BR signaling. The second paper is from the Baulcombe lab in Cambridge and investigates the epigenetic control of transposons. The third paper is from Aberystwyth University and introduces the DeepPod learning framework for the automated counting of Arabidopsis siliques.

The fourth paper includes co-authors from the University of Nottingham in research that conducts a comprehensive analysis of the Arabidopsis auxin receptor gene family. The next paper from the University of Bristol looks at different statistical methods to measure segregation distortion.

The sixth paper is a structural-biology study of an Arabidopsis histone methyltransferase and includes co-authors from King’s College London and the Crick Institute. The penultimate paper includes Brian Forde from Lancaster University as a co-author and analyses the ZmTMM1 transcription factor from maize. The final paper investigates the role of the WRKY6 transcription factor during seed development and includes Ian Bancroft as a co-author.

Srivastava M, Srivastava AK, Orosa-Puente B, Campanaro A, Zhang C, Sadanandom A (2020) SUMO Conjugation to BZR1 Enables Brassinosteroid Signaling to Integrate Environmental Cues to Shape Plant Growth. Curr Biol. doi: 10.1016/j.cub.2020.01.089 Open Access

Moumita Srivastava is first author on this study from Durham University that introduces SUMO regulation of brassinosteroid (BR) signalling through the BZR1 transcription factor. During salt stress Arabidopsis plants arrest growth by upregulating the SUMO protease ULP1a that in turn deSUMOylates BZR1 allowing for its destabilizing interaction with the BIN2 kinase. This study environmental sensing, SUMOylation and the BR response.

Wang Z, Baulcombe DC (2020) Transposon age and non-CG methylation. Nat Commun. doi: 10.1038/s41467-020-14995-6 Open Access

Zhengming Wang and David Baulcombe from the University of Cambridge are authors on this research that assesses the ordering of the mechanisms through which transposon-containing chromatin is silenced. They demonstrate that both RNA-directed DNA methylation (RdDM) and RNA-independent silencing through chromodomain DNA methyltransferases (CMTs) occurs to provide long-term control of transposons and concomitant alterations to the transcriptome.

Hamidinekoo A, Garzón-Martínez GA, Ghahremani M, Corke FMK, Zwiggelaar R, Doonan JH, Lu C (2020) DeepPod: a convolutional neural network based quantification of fruit number in Arabidopsis. Gigascience doi: 10.1093/gigascience/giaa012 Open Access

This research from Aberystwyth University includes Azam Hamidinekoo as first author in which they have developed the DeepPod deep learning framework for the automated identification of Arabidopsis siliques from complex images. They used a training set of over 2400 images to develop prediction software that had comparable success with manual expert human counting. The project code is available on GitHub.

Prigge MJ, Platre M, Kadakia N, Zhang Y, Greenham K, Szutu W, Pandey BK, Bhosale RA, Bennett MJ, Busch W, Estelle M (2020) Genetic analysis of the Arabidopsis TIR1/AFB auxin receptors reveals both overlapping and specialized functions. Elife doi: 10.7554/eLife.54740 Open Access

Mike Prigge from UCSD in California leads this research that includes co-authors from the University of Nottingham. They analyse the phenotypes of all mutant combinations of the six-member TIR1/AFB family of auxin receptors, demonstrating significant functional overlap but that the presence of a functional TIR1 or AFB2 is needed to maintain growth throughout the life cycle. Interestingly they find that the mysterious AFB1 receptor appears to play a specalised role in processes dependent on more rapid auxin-mediated effects.

Coulton A, Przewieslik-Allen AM, Burridge AJ, Shaw DS, Edwards KJ, Barker GLA (2020) Segregation distortion: Utilizing simulated genotyping data to evaluate statistical methods. PLoS One. doi: 10.1371/journal.pone.0228951 Open Access

Alexander Coulton is the first author on this study from the University of Bristol that looks at different statistical tests that are used to confirm segregation distortion in high-density SNP data. In this data they find that the false discovery rate correction best fits the traditional p-value threshold of 0.05 and they perform empirical tests using mapping populations generated between different wheat varieties.

Dobrovolska O, Brilkov M, Madeleine N, Ødegård-Fougner Ø, Strømland Ø, Martin SR, De Marco V, Christodoulou E, Teigen K, Isaksson J, Underhaug J, Reuter N, Aalen RB, Aasland R, Halskau Ø (2020) The Arabidopsis (ASHH2) CW domain binds monomethylated K4 of the histone H3 tail through conformational selection. FEBS J doi: 10.1111/febs.15256

This Norwegian-led study has Olena Dobrovolska as first author and co-authors from King’s College London and the Crick Institute. They have performed a structural analysis using NMR and molecular dynamics of the Arabidopsis Histone lysine methyltransferase ASHH2.

Liu Y, Jia Z, Li X, Wang Z, Chen F, Mi G, Forde B, Takahashi H, Yuan L (2020) Involvement of a truncated MADS-box transcription factor ZmTMM1 in root nitrate foraging. J Exp Bot. doi: 10.1093/jxb/eraa116

Ying Liu leads this Chinese study that includes Brian Forde from Lancaster as a co-author. They show that the maize ZmTMM1 transcription factor is able to rescue the nitrate foraging defect in Arabidopsis anr1agl21 double mutants, demonstrating a link between nitrate-induced transcriptional regulation in grasses and dicots.

Song G, Li X, Munir R, Khan AR, Azhar W, Yasin MU, Jiang Q, Bancroft I, Gan Y (2020) The WRKY6 transcription factor affects seed oil accumulation and alters fatty acid compositions in Arabidopsis thaliana. Physiol Plant. doi: 10.1111/ppl.13082

Ian Bancroft from the University of York is a co-author on this Chinese-led study in which Ge Song is first author. They discovered a high expression level of the WRKY6 transcription factor in developing seeds of Arabidopsis and that wrky6 mutants have larger seeds with altered fatty acid (FA) content and composition. The authors suggest that WRKY6 could be a target for the genetic improvement of FA content in the oil-seed crop of Brassica napus.

GARNet Research Roundup: February 7th 2020

This latest edition of the GARNet Research Roundup begins with two studies that look at different aspects of lateral root formation and include members of Malcolm Bennett’s lab in Nottingham. The first investigates a critical role for hydropatterning in the control of lateral root initiation whilst the second looks at how cell death in overlying tissue layers plays an active role in the control of lateral root emergence.

The third paper is from the John Innes Centre and investigates the mechanism through which a small number of noncoding SNPs can alter chromatin dynamics at the FLC locus. The fourth paper is from Glasgow and assesses a link between auxin signaling and proteins involved in membrane trafficking.

The next paper is from Rothamsted Research and looks at how aerial differences in wheat cultivars can affect the root-associated microbiome. The sixth paper is from the James Hutton Institute and investigates the relationship between phosphate and zinc signaling during the growth of Brassica oleracea.

The final three papers focus on some aspect of plant mechanical strength. The first paper is from Aberystwyth and looks at the how mechanical stress impacts growth of Brachypodium. The next two papers are led from the US and Sweden respectively and include UK co-authors from Leeds, the JIC and York. The first looks at how lignin modifications illicits defence responses whilst the second begins to demonstrate how xyloglucan modifications alter secondary cell wall growth.

von Wangenheim D, Banda J, Schmitz A, Boland J, Bishopp A, Maizel A, Stelzer EHK, Bennett M (2020) Early developmental plasticity of lateral roots in response to asymmetric water availability. Nat Plants. doi: 10.1038/s41477-019-0580-z Open Access with link.

This brief communication is led by Daniel von Wangenheim, who worked with Malcolm Bennett and colleagues at the University of Nottingham. They use light sheet fluorescence microscopy to investigate how the local water environment controls the initiation of lateral root primordia. They show that this response is extremely plastic and that the initiation of pericycle cell files is linked to the external hydrological landscape. This study reveals a potential adaptive advantage when roots forage under heterogeneous soil conditions, which of course exists in all ‘real-world’ situations.

BotanyOne has written a nice blog about this paper and Daniel von Wangenheim has produced a superb explanatory video.

Escamez S, André D, Sztojka B, Bollhöner B, Hall H, Berthet B, Voß U, Lers A, Maizel A, Andersson M, Bennett M, Tuominen H (2020) Cell Death in Cells Overlying Lateral Root Primordia Facilitates Organ Growth in Arabidopsis. Curr Biol. doi: 10.1016/j.cub.2019.11.078 Open Access

Ute Voss and Malcolm Bennett from Nottingham are co-authors on this Finnish-led study in which Sacha Escamez is first author. They show that cell death occuring in advance of emerging lateral roots is an active developmental process rather than a passive effect of lateral root initiation. Plants with a cell-death-deficiency show delayed lateral root development, which is rescued through physical or genetic removal of outer cell files.

Qüesta JI, Antoniou-Kourounioti RL, Rosa S, Li P, Duncan S, Whittaker C, Howard M, Dean C (2020) Noncoding SNPs influence a distinct phase of Polycomb silencing to destabilize long-term epigenetic memory at Arabidopsis FLC. Genes Dev. doi: 10.1101/gad.333245.119 Open Access

This research from the John Innes Centre is led by Julia Qüesta and Rea Antoniou-Kourounioti. They show that four noncoding SNPs in the Lov-1 Arabidopsis accession are responsible for the reactivation of FLC after only a short cold treatment. They combine experimentation and modelling to also propose that the control of FLC reactivation is linked to the extent of DNA replication during the cold period.

Rea discusses this paper on the GARNet Community podcast. Look out for it on February 19th.

Xia L, Marquès-Bueno MM, Karnik RA (2020) Trafficking SNARE SYP132 Partakes in Auxin-associated Root Growth. Plant Physiol. doi: 10.1104/pp.19.01301 Open Access

This short communication is led by Lingfeng Xia in the Karnik lab at the University of Glasgow and looks at the role of auxin in the control of expression of the SNARE protein SYP132 during root growth and the gravitropic response. This linkage is indicative of an important role for membrane trafficking during the auxin response.

Kavamura VN, Robinson RJ, Hughes D, Clark I, Rossmann M, Melo IS, Hirsch PR, Mendes R, Mauchline TH (2020) Wheat dwarfing influences selection of the rhizosphere microbiome. Sci Rep. doi: 10.1038/s41598-020-58402-y
Open Access

Vanessa Kavamura is first author on this study led from Rothamsted Research that looks at how the aerial phenotypes of different wheat cultivars impacts root traits and the soil microbiome. Interestingly they show that taller wheat varieties are predicted to have a more connected bacterial network, which might lead to a more favourably rhizosphere for plant growth.

Pongrac P, Fischer S, Thompson JA, Wright G, White PJ (2020) Early Responses of Brassica oleracea Roots to Zinc Supply Under Sufficient and Sub-Optimal Phosphorus Supply. Front Plant Sci. doi: 10.3389/fpls.2019.01645 Open Access

Paula Pongrac is the first author on this study led from the James Hutton Institute in which they investigate how plants respond to their access to environmental phosphate and zinc. They assess gene expression of Brassica oleracea plants grown under different mineral conditions and reveal important relationships between the response to phosphorous and zinc that will inform future nutrient supply strategies and identification of novel germplasm.

Gladala-Kostarz A, Doonan JH, Bosch M (2020) Mechanical stimulation in Brachypodium distachyon: implications for fitness, productivity and cell wall properties. Plant Cell Environ. doi: 10.1111/pce.13724.

Agnieszka Gladala‐Kostarz who works with Maurice Bosch at Aberystwyth University is the first author on this research that looked at the effect of both wind- and mechanical- treatments on growth of two accessions of Brachypodium distachyon. They catalogue the physical changes that occur in this important base-line study that tracks the relevance of these environmental factors on the multiple growth traits.

Gallego-Giraldo L, Liu C, Pose-Albacete S, Pattathil S, Peralta AG, Young J, Westpheling J, Hahn MG, Rao X, Knox JP, De Meester B, Boerjan W, Dixon RA (2020) ARABIDOPSIS DEHISCENCE ZONE POLYGALACTURONASE 1 (ADPG1) releases latent defense signals in stems with reduced lignin content. Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1914422117 Open Access

Lina Gallego-Giraldo is the first author on the US-led paper that includes Paul Knox and Sara Pose-Albacete from the University of Leeds. In this work they look at the link between lignin modifications and the inappropriate initiation of plant defence responses. They show that cell wall pectin remodeling mediated by the ARABIDOPSIS DEHISCENCE ZONE POLYGALACTURONASE 1 (ADPG1) protein releases defence elicitors and as such provides important information on the link between these processes.

Kushwah S, Banasiak A, Nishikubo N, Derba-Maceluch M, Majda M, Endo S, Kumar V, Gomez L, Gorzsás A, McQueen-Mason S, Braam J, Sundberg B, Mellerowicz EJ (2020) Arabidopsis XTH4 and XTH9 contribute to wood cell expansion and secondary wall formation. Plant Physiol. doi: 10.1104/pp.19.01529 Open Access

Sunita Kushwah leads this Swedish-study that has co-authors from the JIC and York. They investigate a novel role for the XTH4 and XTH9 xyloglucan endo-transglycosylase/ hydrolases during secondary growth in Arabidopsis. The activity of these enzymes has a significant effect on cell wall composition and in the control of wood formation

GARNet Research Roundup: November 22nd 2019

This bumper edition of the GARNet Research Roundup begins with three papers that have a focus on the circadian clock. First is from Cambridge and looks at a novel role for TTG1 in control of the clock. The second paper also includes co-authors from Cambridge and looks at the clock Evening Complex. The final clock paper includes co-authors from York and looks at the new roles for EARLY FLOWERING 3 and GIGANTEA.

The next four papers include researchers from the John Innes Centre. Yiling Ding’s lab lead an exciting study into the role of RNA G-quadruplex to define liquid-liquid phase separations. Next David Seung and Alison Baker look at production of amylose starch across Arabidopsis accessions. The third JIC paper is from the Charpentier lab and looks at nuclear calcium signaling in the root. Finally Lars Ostergaard is a co-author on a paper that identifies a novel biostimulant that controls podshatter in Brassica.

The eighth paper is from Glasgow and describes the bioengineering of plants to express a novel antibiotic bacteriocin.

Next are three papers introduce exciting new research tools. 1. Weibei Yang in the Meyerowitz lab introduces a method for co-labeling of RNAs and protein 2. Researchers in Nottingham introduce RootNav2.0 for the automated measurement of root archtiectures 3. The Haydon Lab has developed a GAL4-GFP luciferase system for tissue-specific gene expression analysis.

Two Photosynthesis-based papers come next with firstly an analysis on the link between metabolism and the light response curve (from Manchester) and secondly a look at the role of aquaporins in control of CO2 conductance (Cambridge and Lancaster).

The fourteenth paper is from Durham and characterises an important protein regulator of the autophagy-dependent degradation pathway whilst the fifteenth is from Cambridge and uses cryo-SEM to analyse cell wall structures.

The penultimate paper is from Birmingham and looks at the role of redox signaling in aphid fecundity and the final paper includes co-authors from RHUL and looks at the interaction between the E2FB and RETINOBLASTOMA-RELATED proteins.

Airoldi CA, Hearn TJ, Brockington SF, Webb AAR, Glover BJ (2019) TTG1 proteins regulate circadian activity as well as epidermal cell fate and pigmentation. Nat Plants. doi: 10.1038/s41477-019-0544-3

This study from the University of Cambridge is led by Chiara Airoldi and introduces a new role for the TRANSPARENT TESTA GLABRA 1 (TTG1) WD-repeat (WDR) subfamily in the regulation of the circadian clock. TTG1 regulates epidermal cell differentiation and pigment production, while LIGHT-REGULATED WD1 and LIGHT-REGULATED WD2A are known to regulate the clock. The triple lwd1 lwd2 ttg1 mutant has no detectable circadian rhythym. This suggests that members of this protein family have undergone subfunctionalization to diverge from their core functions. This paper is of interest to those who research evolution of protein function as well as the to those interested in the control of the circadian clock.

Tong M, Lee K, Ezer D, Cortijo S, Jung J, Charoensawan V, Box MS, Jaeger K, Takahashi N, Mas P, Wigge PA, Seo PJ (2019) The Evening Complex establishes repressive chromatin domains via H2A.Z deposition. Plant Physiol. doi: 10.1104/pp.19.00881

This collaboration between the UK and South Korea is led by Meixuezi Tong and investigates how the Evening Complex (EC) component of the circadian clock interacts with chromatin to control gene expression at dusk. This occurs through direct interaction with the SWI2/SNF2-RELATED complex and together they bind to the core clock genes PRR7 and PRR9, causing the deposition of H2A.Z at these loci subsequent to causing their repression at dusk.

Anwer MU, Davis A, Davis SJ, Quint M (2019) Photoperiod sensing of the circadian clock is controlled by EARLY FLOWERING 3 and GIGANTEA. Plant J. doi: 10.1111/tpj.14604

Amanda Davies and Seth Davies from the University of York are co-authors on this German-led study with Muhammad Anwer as both first and corresponding author. They look at the role of important circadian regulators ELF3 and GIGANTEA through generation of previously unanalysed elf3gi double mutants. In these plants the circadian oscillator fails to synchronize to light-dark cycles even under diurnal conditions, demonstrating that these genes act together to convey photoperiod sensing to the central oscillator.

Zhang Y, Yang M, Duncan S, Yang X, Abdelhamid MAS, Huang L, Zhang H, Benfey PN, Waller ZAE, Ding Y (2019) G-quadruplex structures trigger RNA phase separation. Nucleic Acids Res. doi: 10.1093/nar/gkz978
Open Access

Yueying Zhang is the first author of this study conducted in the lab of Yiliang Ding at the John Innes Centre, in collaboration with the Benfey lab in the USA. They reveal an exciting mode of regulating RNA activity through the formation of RNA G-quadruplex (GQ) complexes. They use the SHORTROOT mRNA as the model for this study, showing that GQ-mediated complex formation can bring liquid-liquid phase separation. This study is of fundamental importance as it provides the first evidence that RNA can adopt structural motifs to trigger and/or maintain the specificity of RNA-driven phase separation.

Seung D, Echevarría-Poza A, Steuernagel B, Smith AM (2019) Natural polymorphisms in Arabidopsis result in wide variation or loss of the amylose component of starch. Plant Physiol. doi: 10.1104/pp.19.01062
Open Access

David Seung at the John Innes Centre the first and corresponding author of this study that used data from the Arabidopsis 1135 Genome project to investigate the prevelance of amylose production. Plants with amylose-free starch have no detrimental phenotypes so the function of this glucose-polymer, that accounts for up to 30% of all natural starch, is unknown. They looked at the polymorphisms within the GRANULE-BOUND STARCH SYNTHASE (GBSS) enzyme, identifying natural accessions that have no GBSS activity yet are viable within their natural environments. This study is a prelude to future research that will discover the adaptive significance of amylose.

Leitão N, Dangeville P, Carter R, Charpentier M (2019) Nuclear calcium signatures are associated with root development. Nat Commun. doi: 10.1038/s41467-019-12845-8
Open Access

Nuno Leitao is first author on this research from the Charpentier lab at the John Innes Centre. They looked at the role of nuclear Ca2+ signalling on primary root meristem development and auxin homeostasis through activity of the nuclear membrane localised ion channel DOES NOT MAKE INFECTIONS 1 (DMI1). This study discovers a previously unappreciated role for intracellular Ca2+ signalling during plant development.

Łangowski Ł, Goñi O, Quille P, Stephenson P, Carmody N, Feeney E, Barton D, Østergaard L, O’Connell S (2019 A plant biostimulant from the seaweed Ascophyllum nodosum (Sealicit) reduces podshatter and yield loss in oilseed rape through modulation of IND expression. Sci Rep. doi: 10.1038/s41598-019-52958-0
Open Access

Lars Ostergaard is a co-author on this Irish-study led by Lukasz Łangowski that investigates the factors that control pod shatter in oil seed rape. They show that the seaweed Ascophyllum nodosum-based biostimulant (Sealicit) is able to reduce podshatter by effecting the expression of the major regulator of pod shattering, INDEHISCENT. This has implications for the use of this compound by farmers wanting to reduce the amount of seed loss due to premature pod shatter.

Rooney WM, Grinter RW, Correia A, Parkhill J, Walker DC, Milner JJ (2019) Engineering bacteriocin-mediated resistance against the plant pathogen Pseudomonas syringae. Plant Biotechnol J. doi: 10.1111/pbi.13294
Open Access

William Rooney at the University of Glasgow is lead author on this study that attempts to combat Pseudomonas syringae infections through expression of a novel protein antibiotic bacteriocin, putidacin. They show that transgenic expression of this bacterial protein provides effective protection against Pseudomonas. This proof of concept opens the possibility for more widespread use of bacteriocins as an effective plant protection strategy.

Yang W, Schuster C, Prunet N, Dong Q, Landrein B, Wightman R, Meyerowitz EM (2019) Visualization of Protein Coding, Long Non-coding and Nuclear RNAs by FISH in Sections of Shoot Apical Meristems and Developing Flowers. Plant Physiol. doi: 10.1104/pp.19.00980
This extended methods paper is led by Weibing Yang at the Sainsbury lab in Cambridge. They have adapted RNA fluorescence in situ hybridization (rnaFISH) to explore RNA localization in the shoot apical meristem of Arabidopsis. They are able to label mRNA as well as long ncRNAs and have developed double labeling to assay two separate RNAs in the same cell and to assess nucleo-cytoplasmic separation of RNA species. Finally they link rnaFISH with fluorescence immunocytochemistry for the simultaneous localization of a single genes mRNA and protein.

Yasrab R, Atkinson JA, Wells DM, French AP, Pridmore TP, Pound MP (2019) RootNav 2.0: Deep learning for automatic navigation of complex plant root architectures. Gigascience. doi: 10.1093/gigascience/giz123
Open Access

Robail Yasrab is lead author on this work from the University of Nottingham that introduces the RootNav2.0 software tool. This was developed by modern deep-learning approaches and allows the fully automated measurement of vertically growth root systems. RootNav2.0 was favourably compared with its semi-automated predecessor RootNav1.0 and can be used for measurement of root architectures from a range of different plant species.

Román Á, Golz JF, Webb AA, Graham IA, Haydon MJ (2019) Combining GAL4 GFP enhancer trap with split luciferase to measure spatiotemporal promoter activity in Arabidopsis. Plant J. doi: 10.1111/tpj.14603

This technical advance is led by Angela Roman, was in the Haydon lab during its time at the University of York. They have used the GAL4-GFP enhancer trap system, to develop a tissue-specific split luciferase assay for non-invasive detection of spatiotemporal gene expression in Arabidopsis. In this example they use the study to measure dynamics of circadian gene expression but is clearly applicable to answer many other experimental questions.

Herrmann HA, Schwartz JM, Johnson GN (2019) From empirical to theoretical models of light response curves – linking photosynthetic and metabolic acclimation. Photosynth Res. doi: 10.1007/s11120-019-00681-2
Open Access

Helena Herrmann is lead author on this work fro the University of Manchester. In this study they developed and then empirically tested a series of simple kinetic models that explains the metabolic changes that are required to alter light response curves (LRCs) across a range of temperatures. This allowed them to show how changes in NADPH and CO2 utilization respond to environmental changes. This provides useful information as to how a plant adapts its metabolic response to light depending on the growth temperature.

Helena explaining her research

Kromdijk J, Głowacka K, Long SP (2019) Photosynthetic efficiency and mesophyll conductance are unaffected in Arabidopsis thaliana aquaporin knock-out lines. J Exp Bot. doi: 10.1093/jxb/erz442

Open Access
Wanne Kromdijk leads this US-led research that includes contributions from the Universities of Cambridge and Lancaster. They looked at the potential role of membrane-bound aquaporins in the control of diffusion conductance for CO2 transfer from substomatal cavity to chloroplast stroma (gm). They tested three aquaporin mutants across a range of light and CO2 concentrations and surprisingly found that they appear to play no significant contribution to the control of gm. The reporting of this type of ‘negative’ result will prevent unnecessary replication of experiments and help to streamline the research process.

Wang P, Pleskot R, Zang J, Winkler J, Wang J, Yperman K, Zhang T, Wang K, Gong J, Guan Y, Richardson C, Duckney P, Vandorpe M, Mylle E, Fiserova J, Van Damme D, Hussey PJ (2019) Plant AtEH/Pan1 proteins drive autophagosome formation at ER-PM contact sites with actin and endocytic machinery. Nat Commun. doi: 10.1038/s41467-019-12782-6
Open Access

Pengwei Wang is first author in this research led from Durham University that incudes Chinese and Belgian collaborators. They show that the AtEH/Pan1 protein is involved with actin cytoskeleton regulated autophagy and recruits multiple other components to autophagosomes during this process. In addition they show vesicle bound-AtEH/Pan1 interact with VAP27-1 at the ER-PM. This demonstrates that AtEH/Pan1 is a key component of the autophagy-dependent degradation pathway.

Lyczakowski JJ, Bourdon M, Terrett OM, Helariutta Y, Wightman R, Dupree P (2019) Structural Imaging of Native Cryo-Preserved Secondary Cell Walls Reveals the Presence of Macrofibrils and Their Formation Requires Normal Cellulose, Lignin and Xylan Biosynthesis. Front Plant Sci. doi: 10.3389/fpls.2019.01398
Open Access

Jan Lyczakowski from the Dupree lab at the University of Cambridge is first author on this study that has adapted low temperature scanning electron microscopy (cryo-SEM) to visualize the cell walls of both angiosperm and gymnosperms. They have used Arabidopsis mutants to reveal that cell wall macrofibrils at composed of cellulose, xylan, and lignin. They demonstrate that cryo-SEM is a useful tool for native nanoscale cell wall architectures.

Rasool B, Karpinska B, Pascual J, Kangasjärvi S, Foyer CH (2019) Catalase, glutathione and protein phosphatase 2A-dependent organellar redox signalling regulate aphid fecundity under moderate and high irradiance. Plant Cell Environ. doi: 10.1111/pce.13669
Brwa Rasool is first author on this collaboration between the Universities of Birmingham and Helsinki that looks at how aphids respond to redox changes in Arabidopsis thaliana grown under different light conditions. They also identified defence-related transcription factors differentially upregulated by aphid predation in different light conditions. Overall they show aphid fecundity is in part determined by the plants cellular redox signaling.

Őszi E, Papdi C, Mohammed B, Pettkó-Szandtner A, Vaskó-Leviczky T, Molnár E, Ampudia CG, Khan S, Lopez-Juez E, Horváth B, Bögre L, Magyar Z (2019) E2FB interacts with RETINOBLASTOMA RELATED and regulates cell proliferation during leaf development. Plant Physiol. doi: 10.1104/pp.19.00212
Erika Oszi is first author of this Hungarian-led research that includes co-authors from Royal Holloway University of London. This research looks at the interaction between the transcription factors E2FB and RETINOBLASTOMA-RELATED (RBR) and how this contributes to cell proliferation during organ development in Arabidopsis leaves. The relationship between these proteins changes throughout the stages of leaf development and is critical to determine final leaf cell number.

GARNet Research Roundup: October 17th 2019

This edition of the GARNet Research Roundup includes a superb selection of papers by scientists from across the UK. First is work from the Spoel lab in Edinburgh that characterizes the fine-tuning of NPR1 activity during the plant immune response. Second is work from SLCU and the University of Helsinki that is an extensive investigation into the molecular basis of cambial development. Next is research from Nottingham that looks at the importance of soil macro-structures during the growth of wheat roots.

Fourth are three papers that highlight the breadth of research occurring at the John Innes Centre. The first paper is from Enrico Coen’s lab that applies their expertise in computational modeling to leaf development in the carnivorous plant Utricularia gibba. Second is work from Saskia Hogenhout’s lab that looks at immunity to infection by Phytoplasma pathogens. Last is work from Lars Ostergaard’s lab that characterises the role of Auxin Binding promoter elements in floral development.

The seventh paper from Bristol and Glasgow looks at shade avoidance signaling via PIF5, COP1 and UVR8 whilst the eighth paper, which is from Rothamsted, demonstrates how metabolic engineering in Arabidopsis seeds can result in a high proportion of human milk fat substitute. The next paper is from the University of Durham and investigates how the composition of the Arabidopsis cell wall impacts freezing tolerance. The first author of this paper, Dr Paige Panter discusses the paper on the GARNet community podcast.

The tenth paper is from Julia Davies’s lab at the University of Cambridge and introduces an uncharacterised response to extracellular ATP signals in Arabidopsis roots. The next paper is from Mike Blatt’s group at University of Glasgow and characterises a new interaction between vesicular transport and ion channels. The penultimate entry includes co-authors from the JIC on a Chinese-led study that demonstrates improved seed vigour in wheat through overexpression of a NAC transcription factor. Finally are two methods papers taken from a special journal issue on ‘Plant Meiosis’.

Skelly MJ, Furniss JJ, Grey HL, Wong KW, Spoel SH (2019) Dynamic ubiquitination determines transcriptional activity of the plant immune coactivator NPR1. Elife. doi: 10.7554/eLife.47005
Open Access

Michael Skelly is lead author on this paper from the lab of current GARNet chair Steven Spoel. In it they investigate the mechanisms that fine-tune the function of NPR1, a key player in the plant immune response. Progressive ubiquitination of NPR1 by an E3 ligase causes both its interaction with target genes and its subsequent degradation by an E4 ligase. This latter occurrence is opposed by the deubiquitinase activity of UBP6/7, setting up a complex regulatory environment that allows the plant to rapidly response to pathogen attack.

Zhang J, Eswaran G, Alonso-Serra J, Kucukoglu M, Xiang J, Yang W, Elo A, Nieminen K, Damén T, Joung JG, Yun JY, Lee JH, Ragni L, Barbier de Reuille P, Ahnert SE, Lee JY, Mähönen AP, Helariutta Y (2019) Transcriptional regulatory framework for vascular cambium development in Arabidopsis roots. Nat Plants. doi: 10.1038/s41477-019-0522-9

This pan-European-Korean collaboration has Jing Zhang from the University of Helsinki and the Sainsbury Laboratory, University of Cambridge as first author. They use cambium cell-specific transcript profiling and follow-on network analysis to discover 62 new transcription factors involved in cambial development in Arabidopsis. This information was used to engineer plants with increased radial growth through ectopic cambial activity as well as to generate plants with no cambial activity. This understanding provides a platform for possible future improvements in production of woody biomass.

Atkinson JA, Hawkesford MJ, Whalley WR, Zhou H, Mooney SJ (2019) Soil strength influences wheat root interactions with soil macropores. Plant Cell Environ. doi: 10.1111/pce.13659
This work is led from the University of Nottingham by John Atkinson and Sacha Mooney. They use X-ray Computed Tomography to investigate a trait called trematotropism, which applies to the ability of deep rooting plants to search out macropores and avoid densely packed soil. They show root colonisation of macropores is an important adaptive trait and that strategies should be put in place to increase these structures within the natural soil environment.

Lee KJI, Bushell C, Koide Y, Fozard JA, Piao C, Yu M, Newman J, Whitewoods C, Avondo J, Kennaway R, Marée AFM, Cui M, Coen E (2019) Shaping of a three-dimensional carnivorous trap through modulation of a planar growth mechanism. PLoS Biol. doi: 10.1371/journal.pbio.3000427
Open Access

Karen Lee, Claire Bushell and Yohei Koide are co-first authors on this work led by Enrico Coen at the John Innes Centre and Minlong Cui at the Zhejiang Agriculture and Forestry University in China. This study uses 3D imaging, cellular and clonal analysis, combined with computational modelling to analyse the development of cup-shaped traps of the carnivorous plant Utricularia gibba. They identify growth ansiotrophies that result in the final leave shape that develops from an initial near-spherical form. These processes have some similarities to the polar growth seen in Arabidopsis leaves. Overall they show that ‘simple modulations of a common growth framework underlie the shaping of a diverse range of morphologies’.

Pecher P, Moro G, Canale MC, Capdevielle S, Singh A, MacLean A, Sugio A, Kuo CH, Lopes JRS, Hogenhout SA (2019) Phytoplasma SAP11 effector destabilization of TCP transcription factors differentially impact development and defence of Arabidopsis versus maize. PLoS Pathog. doi: 10.1371/journal.ppat.1008035
Open Access

This work from Saskia Hogenhout’s lab at the John Innes Centre is led by Pascal Pecher and Gabriele Moro. They look at the effect of SAP11 effectors from Phytoplasma species that infect either Arabidopsis or maize. They demonstrate that although both related versions of SAP11 destabilise plant TCP transcription factors, their modes of action have significant differences. Please look out for Saskia discussing this paper on the GARNet Community podcast next week.

Kuhn A, Runciman B, Tasker-Brown W, Østergaard L 92019) Two Auxin Response Elements Fine-Tune PINOID Expression During Gynoecium Development in Arabidopsis thaliana. Biomolecules. doi: 10.3390/biom9100526
Open Access

Andre Kuhn is first author of this research from Lars Østergaard’s lab at the John Innes Centre. They functional characterise two Auxin-responsive Elements (AuxRE) within the promotor of the PINOID gene, which are bound by the ETITIN/ARF3 Auxin Response Factor. Alteration of this AuxRE causes phenotypic changes during flower development demonstrating that even with a complex regulatory environment, small changes to cis-elements can have significant developmental consequences.

Sharma A, Sharma B, Hayes S, Kerner K, Hoecker U, Jenkins GI, Franklin KA (2019) UVR8 disrupts stabilisation of PIF5 by COP1 to inhibit plant stem elongation in sunlight. Nat Commun. doi: 10.1038/s41467-019-12369-1
Open Access

Ashutosh Sharma is first author of this UK-Spanish-Germany collaboration led by Keara Franklin at University of Bristol. They have characterised the interaction between three significant molecular players that function during the shade avoidance response in Arabidopsis; PIF5, UVR8 and COP1. In shaded conditions, UVR8 indirectly promotes rapid degradation of PIF5 through their interactions with the E3 ubiquitin ligase COP1.

van Erp H, Bryant FM, Martin-Moreno J, Michaelson LV, Bhutada G, Eastmond PJ (2019) Engineering the stereoisomeric structure of seed oil to mimic human milk fat. Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1907915116

Open Access

Harrie Van Arp and Peter Eastmond at Rothamsted Research lead this extremely translational study in which they have modified the metabolic pathway for triacylglycerol (TAG) biosynthesis. By modifying the location of one biosynthesis enzyme and removing the activity of another, the fats produced in these Arabidopsis seeds are enriched to contain TAGs that are similar to those found in human milk. They propose that this technology could be used to develop a source of plant-derived human milk fat substitute.

Panter PE, Kent O, Dale M, Smith SJ, Skipsey M, Thorlby G, Cummins I, Ramsay N, Begum RA, Sanhueza D, Fry SC, Knight MR, Knight H (2019) MUR1-mediated cell-wall fucosylation is required for freezing tolerance in Arabidopsis thaliana. New Phytol. doi: 10.1111/nph.16209

Paige Panter led this work as part of her PhD at the University of Durham in the lab of Heather Knight. They characterise the role of the MUR1 protein in the control of cell wall fucosylation and how this contributes to plant freezing tolerance. Paige discusses this paper and the long history of MUR1 on the GARNet Community podcast. Please check it out!

Wang L, Stacey G, Leblanc-Fournier N, Legué V, Moulia B, Davies JM (2019) Early Extracellular ATP Signaling in Arabidopsis Root Epidermis: A Multi-Conductance Process. Front Plant Sci. doi: 10.3389/fpls.2019.01064.

Open Access

The UK-French collaboration is led by Limin Wang from Julia Davies’s lab in Cambridge. They use patch clamp electrophysiology to identify previously uncharacterized channel conductances that respond to extracellular ATP across the root elongation zone epidermal plasma membrane.

Waghmare S, Lefoulon C, Zhang B, Lileikyte E, Donald NA, Blatt MR (2019) K+ channel-SEC11 binding exchange regulates SNARE assembly for secretory traffic. Plant Physiol. doi: 10.1104/pp.19.00919

Open Access

This work from Mike Blatt’s lab in Glasgow is led by Sakharam Waghmare. They look at the interaction between SNARE proteins, which are involved in vesicular fusion and K+ channels, which help control turgor pressure during cell expansion. Through combining analysis of protein-protein interactions and electrophysiological measurement they have found that this interaction requires the activity of the regulatory protein SEC11.

Li W, He X, Chen Y, Jing Y, Shen C, Yang J, Teng W, Zhao X, Hu W, Hu M, Li H, Miller AJ, Tong Y (2019) A wheat transcription factor positively sets seed vigour by regulating the grain nitrate signal. New Phytol. doi: 10.1111/nph.16234
Wenjing Li is first author of this Chinese study that includes Yi Chen and Anthony Miller from the John Innes Centre as co-authors. This research shows that seed vigour and nitrate accumulation in wheat is regulated by the TaNAC2 transcriptions factor through its control of the TaNRT2.5 nitrate transporter. The authors suggest that both genes could be used as potential future targets to increase grain yield and nitrogen use efficiency.

The Special Issue of Methods in Molecular Biology on Plant Meiosis includes papers from the University of Cambridge, led by Christophe Lambing and the James Hutton Institute, led by Benoit Darrier.

Lambing C, Choi K, Blackwell AR, Henderson IR (2019) Chromatin Immunoprecipitation of Meiotically Expressed Proteins from Arabidopsis thaliana Flowers. Methods Mol Biol. doi: 10.1007/978-1-4939-9818-0_16
Darrier B, Arrieta M, Mittmann SU, Sourdille P, Ramsay L, Waugh R, Colas I (2019) Following the Formation of Synaptonemal Complex Formation in Wheat and Barley by High-Resolution Microscopy. Methods Mol Biol. doi: 10.1007/978-1-4939-9818-0_15

GARNet Research Roundup: July 26th 2019

This summer-time-reading bumper edition of the GARNet Research Roundup begins with two papers from the University of Sheffield that each use advanced imaging techniques. Firstly Andrew Fleming’s group leads a study on the link between stomatal function and mesophyll space morphology. Second is a study from Matthew Johnson’s group that looks at the dynamic arrangement of thylakoid stacks.

Next are two papers that include Alison Smith from the JIC as a corresponding author. The first also includes Vasilios Andriotis from the University of Newcastle and looks at the role of the plastidial pentose phosphate pathway during post-germination growth. Second uses a gene-editing strategy to generate potatoes with altered starch morphologies.

The fifth paper also looks at starch; researchers from Cambridge and Norwich are involved in a study that characterises the role of the LIKE SEX4 1 protein in starch degradation.

The sixth paper is from Aberystwyth University and identifies a transcription factor that alters secondary cell wall composition in Brachypodium and maize. Next is research from the University of Bath that looks at the role of a protein S-acyl transferase during seed germination.

The eighth and ninth papers are led by Spanish research groups and include contributions from UK-based co-authors in Cambridge and Nottingham, working on photoperiod perception or phosphate signaling respectively.

The tenth paper features work from Cardiff University and looks at the role of heterologous expression of the Arabidopsis WEE1 protein. The Bancroft lab from the University of York leads the next paper that investigates glucosinolate signaling in Brassica napus.

The final three manuscripts are methods papers. The first from Edinburgh introduces a new NanoLUC reporter whilst the other two include techniques involved in the investigation of light-regulated growth processes.

Lundgren MR, Mathers A, Baillie AL, Dunn J, Wilson MJ, Hunt L, Pajor R, Fradera-Soler M, Rolfe S, Osborne CP, Sturrock CJ, Gray JE, Mooney SJ, Fleming AJ (2019) Mesophyll porosity is modulated by the presence of functional stomata. Nat Commun. doi: 10.1038/s41467-019-10826-5

Open Access

This UK-wide study is led from Andrew Fleming’s lab in Sheffield and includes Marjorie Lundgren as first author (now working in Lancaster). They use microCT imaging alongside more traditional measurements linked to analysis of gas exchange to show that mesophyll airspace formation is linked to stomatal function in both Arabidopsis and wheat. This allows the authors to propose that coordination of stomata and mesophyll airspace pattern underpins water use efficiency in crops.

Wood WH, Barnett SFH, Flannery S, Hunter CN, Johnson MP (2019) Dynamic thylakoid stacking is regulated by LHCII phosphorylation but not its interaction with photosystem I. Plant Physiol. doi: 10.1104/pp.19.00503

Open Access

William Wood is the first author on this study from the University of Sheffield that uses 3D structured illumination microscopy (3D-SIM) to look at the dynamics of thylakoid stacking in both Arabidopsis and spinach. They show that the processes they observe are dependent on light harvesting complex II phosphorylation.

Andriotis VME, Smith AM (2019) The plastidial pentose phosphate pathway is essential for postglobular embryo development in Arabidopsis. Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1908556116

Open Access

Vasilios Andriotis (now at the University of Newcastle) is the lead author of this work performed in Alison Smith’s lab at the JIC. They look at the role of the plastidial oxidative pentose phosphate pathway (OPPP) during embryo development. This involved demonstrating that production of ribose-5-phosphate (R5P), which in turn leads to synthesis of purine nucleotides, is a critical function of the OPPP.

Tuncel A, Corbin KR, Ahn-Jarvis J, Harris S, Hawkins E, Smedley MA, Harwood W, Warren FJ, Patron NJ, Smith AM (2019) Cas9-mediated mutagenesis of potato starch-branching enzymes generates a range of tuber starch phenotypes. Plant Biotechnol J. doi: 10.1111/pbi.13137

Open Access

Alison Smith and Nicola Patron who work in Norwich Research Park are corresponding authors of this study that includes Aytug Tuncel as first author. They have used Cas9-mediated gene editing to generate potato plants that have a range of different tuber starch structures. This shows that gene-editing techniques allows the transgene-free alteration to generate potentially healthier crops.

Schreier TB, Umhang M, Lee SK, Lue WL, Shen Z, Silver D, Graf A, Müller A, Eicke S, Stadler M, Seung D, Bischof S, Briggs SP, Kötting O, Moorhead GB, Chen J, Zeeman SC (2019) LIKE SEX4 1 acts as a β-amylase-binding scaffold on starch granules during starch degradation. Plant Cell. doi: 10.1105/tpc.19.00089

Open Access

Tina Schreier from the University of Cambridge is the first author on this international study led from Switzerland that also includes Alexander Graf and David Seung from the JIC as co-authors. This study defines a precise role for the LIKE SEX FOUR 1 (LSF1) protein that binds starch and is required for normal starch degradation. Through a variety of experiments they show that the glucan binding, rather than phosphatase activity, is required for LSF1 function during starch degradation.

Bhatia R, Dalton S, Roberts LA, Moron-Garcia OM, Iacono R, Kosik O, Gallagher JA, Bosch M (2019) Modified expression of ZmMYB167 in Brachypodium distachyon and Zea mays leads to increased cell wall lignin and phenolic content. Sci Rep. doi: 10.1038/s41598-019-45225-9

Open Access

Rakesh Bhatia is the first author on this work from the lab of Maurice Bosch at Aberystwyth University. They overexpress the maize MYB transcription factor ZmMYB167 in both Brachypodium and maize. Both species show increased lignin content with Brachypodium but not maize showing a biomass deficit. This indicates that ZmMYB167 could be a useful molecular tool for the alteration of secondary cell wall biosynthesis.

Li Y, Xu J, Li G, Wan S, Batistic O, Sun M, Zhang Y, Scott R, Qi B (2019) Protein S-acyl Transferase 15 is Involved in Seed Triacylglycerol Catabolism during Early Seedling Growth in Arabidopsis (2019) J Exp Bot. doi: 10.1093/jxb/erz282

First author on this UK-Chinese collaboration is Yaxiao Li who works with Baoxiu Qi at the University of Bath. The authors characterise the function of Arabidopsis Protein Acyl Transferase 15, AtPAT15. This protein is involved in essential β-oxidation of triacylglycerols during post-germination growth.

Ramos-Sánchez JM, Triozzi PM, Alique D, Geng F, Gao M, Jaeger KE, Wigge PA, Allona I, Perales M (2019) LHY2 Integrates Night-Length Information to Determine Timing of Poplar Photoperiodic Growth. Curr Biol. doi: 10.1016/j.cub.2019.06.003

Open Access

This Spanish-led study includes co-authors from the Sainsbury Laboratory in Cambridge and attempts to define the factors that control photoperiod perception in trees, using poplar as a model system. FLOWERING LOCUS T2 (FT2) has been previously shown to be involved in this process and this study builds on that work to show that night-length information is transmitted by the clock gene LATE ELONGATED HYPOCOTYL 2 (LHY2) and is able to control FT2 expression.

Silva-Navas J, Conesa CM, Saez A, Navarro-Neila S, Garcia-Mina JM, Zamarreño AM, Baigorri R, Swarup R, Del Pozo JC (2019) Role of cis-zeatin in root responses to phosphate starvation. New Phytol. doi: 10.1111/nph.16020

Ranjan Swarup from the University of Nottingham is a co-author on this Spanish-led study that has Javier Silva-Navas as first author. Through analysis of dark-grown seedlings they have identified a set of new genes involved in root phosphate signaling. In addition they provide evidence of a links between cytokinin and phosphate signaling through modulation of the cell cycle.

Siciliano I, Lentz Grønlund A, Ševčíková H, Spadafora ND, Rafiei G, Francis D, Herbert RJ, Bitonti MB, Rogers HJ, Lipavská H (2019) Expression of Arabidopsis WEE1 in tobacco induces unexpected morphological and developmental changes. Sci Rep. 2019 Jun 18;9(1):8695. doi: 10.1038/s41598-019-45015-3

Open Access

Ilario Siciliano leads this work that includes colleagues from Hilary Rogers’ lab at Cardiff University. The WEE1 protein regulates the cell cycle across eukaryote lineages. In this work they show that overexpression of AtWEE1 in tobacco causes precocious flowering and increased shoot morphogenesis of stem explants whilst in cell culture this WEE1 OX causes smaller cell sizes.

Kittipol V, He Z, Wang L, Doheny-Adams T, Langer S, Bancroft I (2019) Genetic architecture of glucosinolate variation in Brassica napus. J Plant Physiol. doi: 10.1016/j.jplph.2019.06.001

Open Access

This study from the Bancroft lab at the University of York is led by Varanya Kittipol. Through use of Associative Transcriptomics (AT) across a diversity panel of 288 Brassica napus genotypes they are able to identify a set of genes involved in synthesis of glucosinate hydrolysis products.

Urquiza-García U, Millar AJ (2019). Expanding the bioluminescent reporter toolkit for plant science with NanoLUC. Plant Methods. doi: 10.1186/s13007-019-0454-4

Open Access

This study from the University of Edinburgh introduces NanoLUC, a new more stable luciferase-based reporter for use by the plant community.

The final two papers are methods papers that focus on different aspects of light-regulated growth. These are from the University of Southampton and University of York.

Terry MJ, Kacprzak SM (2019) A Simple Method for Quantification of Protochlorophyllide in Etiolated Arabidopsis Seedlings. Methods Mol Biol. doi: 10.1007/978-1-4939-9612-4_14

Oakenfull RJ, Ronald J, Davis SJ (2019) Measuring Phytochrome-Dependent Light Input to the Plant Circadian Clock. Methods Mol Biol. doi: 10.1007/978-1-4939-9612-4_15

GARNet Research Roundup: July 5th 2019

This edition of the GARNet research roundup begins with a study from the University Leicester that investigates the rate of selection of genes expressed in Arabidopsis pollen.

The second and third papers focus on the function of members of the AP2 family of transcription factors. Sarah McKim’s lab in Dundee characterizes the role of APETALA2 during barley stem elongation whilst the other paper investigates the function of the Arabidopsis PUCHI gene and includes co-authors from the University of Nottingham.

The fourth paper is from Lars Ostergaard’s lab at the John Innes Centre and demonstrates the benefit of using models to understand developmental processes in crop plants. The next paper from the University of Glasgow investigates the plant response to low fluence rates of UV-B light.

The penultimate paper features authors from Oxford Brookes University and characterizes a novel LINC-KASH protein in maize whilst the final paper is from the University of Cambridge and investigates the novel function of two members of DUF579 family in methylation of glucuronic acid residues.

Harrison MC, Mallon EB, Twell D, Hammond RL (2019) Deleterious mutation accumulation in Arabidopsis thaliana pollen genes: a role for a recent relaxation of selection. Genome Biol Evol. doi: 10.1093/gbe/evz127

Open Access

This research from Hammond and Twell lab’s at the University of Leicester uses Arabidopsis to investigate the hypothesis that pollen genes evolve faster than sporophytic genes. This study is challenging to perform in Arabidopsis as for the past million years the plant has been self-compatible, which causes reduction in pollen competition, increased homozygosity and a dilution of masking in diploid expressed, sporophytic genes. This study has two main findings: firstly prior to becoming self-compatible pollen genes evolved faster than sporophytic genes. Secondly, since becoming self-compatible selection has relaxed causing higher polymorphism levels and a higher build-up of deleterious mutations.

Patil V, McDermott HI, McAllister T, Cummins M, Silva JC, Mollison E, Meikle R, Morris J, Hedley PE, Waugh R, Dockter C, Hansson M, McKim SM (2019) APETALA2 control of barley internode elongation. Development. doi: 10.1242/dev.170373

Open Access

Vrushali Patil leads his study from the lab of current GARNet committee member Sarah McKim at the James Hutton Institute in Dundee. They show that the APETALA2 (AP2) transcription factor is necessary for stem elongation in Barley. In addition they demonstrate that AP2 expression is controlled by the activity of the microRNA mi172 as well as jasmonate signaling.

Trinh DC, Lavenus J, Goh T, Boutté Y, Drogue Q, Vaissayre V, Tellier F, Lucas M, Voß U, Gantet P, Faure JD, Dussert S, Fukaki H, Bennett MJ, Laplaze L, Guyomarc’h S (2019) PUCHI regulates very long chain fatty acid biosynthesis during lateral root and callus formation. Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1906300116

Julien Lavenus, Ute Voß and Malcolm Bennett from University of Nottingham are co-authors on this French-led study that investigates the mechanism by which the AP2 family transcription factor PUCHI controls lateral root development. By performing a transcriptional analysis of developing lateral root cells they show that genes involved in very long chain fatty acid (VLCFA) biosynthesis enzymes are induced in a PUCHI dependent manner. Concomitantly they show puchi-1 mutant roots have reduced VLCFA content when compared with wildtype roots. They conclude that PUCHI regulates VLCFA biosynthesis as part of a pathway controlling cell proliferation during lateral root formation.

Stephenson P, Stacey N, Brüser M, Pullen N, Ilyas M, O’Neill C, Wells R, Østergaard L (2019) The power of model-to-crop translation illustrated by reducing seed loss from pod shatter in oilseed rape. Plant Reprod. doi: 10.1007/s00497-019-00374-9

Open Access

Pauline Stephenson and Lars Østergaard at the John Innes Centre lead this study in which they demonstrate that lessons learnt from understanding the genes involved in fruit ripening in Arabidopsis lead to an ability to adjust the pod-opening process in oilseed rape. They have combined two mutant alleles, first characterized in Arabidopsis, to develop OSR plants that have significantly increased yield. In addition they present a new software tool for the analysis of pod shatter data in other crops plants.

O’Hara A, Headland LR, Díaz-Ramos LA, Morales LO, Strid Å, Jenkins GI (2019) Regulation of Arabidopsis gene expression by low fluence rate UV-B independently of UVR8 and stress signaling. Photochem Photobiol Sci. doi: 10.1039/c9pp00151d

Open Access

This UK-Swedish collaboration is led by Andrew O’Hara from the Jenkins lab in the University of Glasgow. They continue the lab focus on the UV-B receptor UVR8, in this case performing a transcriptomic analysis of wildtype and uvr8 mutants grown under low UV-B fluence rates. They analyse one differentially expressed gene in more detail, the transcription factor ARABIDOPSIS NAC DOMAIN CONTAINING PROTEIN 13 (ANAC13), which was induced by UV-B but by the activity of any other photoreceptor.

Gumber HK, McKenna JF, Tolmie AF, Jalovec AM, Kartick AC, Graumann K, Bass HW (2019) MLKS2 is an ARM domain and F-actin-associated KASH protein that functions in stomatal complex development and meiotic chromosome segregation Nucleus. doi: 10.1080/19491034.2019.1629795

Open Access

Hardeep Gumber is first author on this US-led study that includes Joe KcKenna, Andrea Tolmie and Katja Graumann from Oxford Brookes as co-authors. They characterise the Maize LINC KASH AtSINE-like2 protein, MLKS2, whose targeting to the nuclear periphery requires its N-terminal armadillo repeats. Mutant mlks2 plants have pleiotropic plant phenotypes and on a nuclear level show defects in chromosome segregation and positioning. These findings support a model in which cytoplasmic actin is linked to chromatin through the LINC-KASH nuclear envelope network.

Temple H, Mortimer JC, Tryfona T, Yu X, Lopez-Hernandez F, Sorieul M, Anders N, Dupree P (2019) Two members of the DUF579 family are responsible for arabinogalactan methylation in Arabidopsis. Plant Direct. doi: 10.1002/pld3.117

Open Access

Henry Temple is first author on this work from the University of Cambridge that characterizes two members of the DUF579 family (AGM1 and AGM2). These proteins are required for 4-O-methylation of glucuronic acid within highly glycosylated arabinogalactan proteins (AGPs).

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July 2020

Welcome , today is Tuesday, July 7, 2020