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: Jan 24th 2020

The first GARNet Research Roundup of 2020 begins with a study from the University of Dundee at the James Hutton Institute in which they have adapted nanopore direct sequencing to analyse the Arabidopsis mRNA methylome. The second study is also from Dundee and is an analysis of alternative splicing in C4 sugarcane.

The next two papers look at the control of stomatal development. In the first, researchers from Bristol investigate the integration of temperature and light-induced signals whilst the second paper is from Sheffield and looks at the role, or lack thereof, of the HY5 protein. The fifth paper is also from Sheffield and looks at the role of the MALECTIN DOMAIN KINESIN 2 protein in dividing tissues.

The next two papers investigate the control of lateral root formation. Firstly researchers from Glasgow look at how potassium signaling integrates with both the mechanisms of RNA-directed DNA-methylation and the auxin response. The other paper looks at how auxin signaling integrates with the plasmodesmata development and includes co-authors from the University of Nottingham.

The eighth paper is led from Nottingham and looks at the role of the PROTEOLYSIS (PRT)1 during the plant immune response whilst the next paper, which is from the University of Cambridge, also looks at plant immunity, specifically at how the biosynthesis of phytic acid impacts this response.

The remaining four papers include UK-based co-authors from University of South Wales, Rothamsted and Cardiff, Durham, Oxford and Aberystwyth in international research teams led from Malaysian (the expression of Acyl-CoA-binding proteins in oil palm), China (the effect of silver nanoparticles on plant growth), Japan (convergent evolution of lateral organ formation) and Chile (the factors that influence grain filling in wheat) respectively.

Parker MT, Knop K, Sherwood AV, Schurch NJ, Mackinnon K, Gould PD, Hall AJ, Barton GJ, Simpson GG (2020) Nanopore direct RNA sequencing maps the complexity of Arabidopsis mRNA processing and m(6)A modification. Elife. doi: 10.7554/eLife.49658 Open Access

Matt Parker, Kasia Knop, Anya Sherwood and Nicholas Schurch are co-first authors on this study from the University of Dundee at the James Hutton Institute in which they perform direct RNA sequencing using a nanopore sequencer. They used this technical advance to analyse the mRNA (m6A) methylome and reveal a contribution to the control of the circadian clock. Future use of this technique will undoubtedly allow for an improved annotation of the Arabidopsis genome (and others).

Dantas LLB, Calixto CPG, Dourado MM, Carneiro MS, Brown JWS, Hotta CT (2019) Alternative Splicing of Circadian Clock Genes Correlates With Temperature in Field-Grown Sugarcane. Front Plant Sci. doi: 10.3389/fpls.2019.01614 Open Access

This study is led from Brazil with Luiza Dantas as first author and includes co-authors from the University of Dundee at the James Hutton Institute. They investigate the level of alternative splicing (AS) in commercial sugarcane, which is an important C4 crop. Tissue samples were collected in winter and summer and this analysis reveals temperature- and organ-dependent differences in the levels of AS across a set of genes under circadian control.

Kostaki KI, Coupel-Ledru A, Bonnell VC, Gustavsson M, Sun P, Mclaughlin FJ, Fraser DP, McLachlan DH, Hetherington AM, Dodd AN, Franklin KA (2020). Guard cells integrate light and temperature signals to control stomatal aperture. Plant Physiol. doi: 10.1104/pp.19.01528 Open Access

Kalliopi-Ioanna Kostaki is first author on this study from the University of Bristol that begins to unpick the mechanisms that integrate light and temperature signals in the control of stomatal development. These signals converge on phototropin photoreceptors and multiple members of the 14-3-3 protein family. This work also reveals a currently uncharacterised pathway that controls temperature regulation of guard cell movement.

Zoulias N, Brown J, Rowe J, Casson SA (2020) HY5 is not integral to light mediated stomatal development in Arabidopsis. PLoS One. doi: 10.1371/journal.pone.0222480 Open Access

Nick Zoulias is first author on this study from the Casson lab at University of Sheffield. ELONGATED HYPOCOTYL 5 (HY5) is a key regulator of light-mediated development yet in this study the authors show that the HY5-signaling cascade does not play a role in stomatal development. This key finding shows that phytochrome and cryptochrome signaling in guard cells is transmitted via non-HY5 signaling components.

Galindo-Trigo S, Grand TM, Voigt CA, Smith LM (2020) A malectin domain kinesin functions in pollen and seed development in Arabidopsis. J Exp Bot doi: 10.1093/jxb/eraa023
This research from the Smith lab at the University of Sheffield is led by Sergio Galindo-Trigo. They show that MALECTIN DOMAIN KINESIN 2 (MDKIN2) is involved in pollen, embryo and endosperm development. Malectin domains bind polysaccharides and peptides when found extracellularly in receptor-like kinases so this might suggest that in dividing tissues MDKIN2 plays a role during the physical division of cells.

Shahzad Z, Eaglesfield R, Carr C, Amtmann A (2020) Cryptic variation in RNA-directed DNA-methylation controls lateral root development when auxin signalling is perturbed. Nat Commun. doi: 10.1038/s41467-019-13927-3 Open Access

Zaigham Shahzad at the University of Glasgow is the first author in this study that looks at the relationship between potassium deficiency and lateral root formation. This effect is mediated via the impact of CLSY1, a key component of the RNA-directed DNA-methylation machinery, on the transcriptional repression of the AuxIAA protein IAA27. Interestingly this system appears to act as a backup to the auxin-dependent proteolysis pathway that is primarily responsible for the control of IAA27 activity.

Sager R, Wang X, Hill K, Yoo BC, Caplan J, Nedo A, Tran T, Bennett MJ, Lee JY (2020) Auxin-dependent control of a plasmodesmal regulator creates a negative feedback loop modulating lateral root emergence. Nat Commun. doi: 10.1038/s41467-019-14226-7.

This US study is led by Ross Sager and includes co-authors from the University of Nottingham. This research links the role of auxin in lateral root formation with plasmodesmata development through control of the plasmodesmal regulator PDLP5. They present a model wherein molecules required for lateral root emergence transit through plasmodesmata following an inductive auxin signal.

Till CJ, Vicente J, Zhang H, Oszvald M, Deery MJ, Pastor V, Lilley KS, Ray RV, Theodoulou FL, Holdsworth MJ (2019) The Arabidopsis thaliana N-recognin E3 ligase PROTEOLYSIS1 influences the immune response. Plant Direct. doi: 10.1002/pld3.194 Open Access

Christopher Till, Jorge Vicente and Hongtao Zhangis are co-first authors on this research led from the University of Nottingham and Rothamsted Research that involves use of quantitative proteomics to define the role of the N-recognin E3 ligase PROTEOLYSIS (PRT)1 during the plant immune response.

Poon JSY, Le Fevre RE, Carr JP, Hanke DE, Murphy AM (2019) Inositol hexakisphosphate biosynthesis underpins PAMP-triggered immunity to Pseudomonas syringae pv. tomato in Arabidopsis thaliana but is dispensable for establishment of systemic acquired resistance. Mol Plant Pathol. doi: 10.1111/mpp.12902
This research from the University of Cambridge is led by Jacquelyne Poon and Alex Murphy and looks at the role of the phytic acid (inositol hexakisphosphate, InsP6) biosynthesis in dividing tissues during the plant immune response. They characterize Arabidopsis plants with mutations in biosynthetic enzymes to show that there are multiple mechanisms of basal resistance that are dependent upon InsP6.

Amiruddin N, Chan PL, Azizi N, Morris PE, Chan KL, Ong PW, Rosli R, Masura SS, Murphy DJ, Sambanthamurthi R, Haslam RP, Chye ML, Harwood JL, Low EL (2019) Characterisation of Oil Palm Acyl-CoA-Binding Proteins and Correlation of their Gene Expression with Oil Synthesis. Plant Cell Physiol. doi: 10.1093/pcp/pcz237.
Nadzirah Amiruddin is lead author on this Malaysian-led research that includes collaborators from the University of South Wales, Rothamsted Research and Cardiff University. This paper looks at the expression of Acyl-CoA-binding proteins (ACBPs) in oil palm; providing important information about the role of this protein family during oil synthesis in the world’s most important oil crop.

Wang L, Sun J, Lin L, Fu Y, Alenius H, Lindsey K, Chen C (2019) Silver nanoparticles regulate Arabidopsis root growth by concentration-dependent modification of reactive oxygen species accumulation and cell division. Ecotoxicol Environ Saf. doi: 10.1016/j.ecoenv.2019.110072.

This Chinese-study is led by Likai Wang and includes Keith Lindsey from Durham University as a co-author. They look at the effect of silver nanoparticles (AgNPs) on growth of Arabidopsis. AgNPs are taken up by roots and have opposing effects at either 50 mg L-1 or 100mg mg L-1. This is an important preliminary study to understand how plant growth might be altered if AgNP’s are used as a delivery mechanism.

Naramoto S, Jones VAS, Trozzi N, Sato M, Toyooka K, Shimamura M, Ishida S, Nishitani K, Ishizaki K, Nishihama R, Kohchi T, Dolan L, Kyozuka J (2019) A conserved regulatory mechanism mediates the convergent evolution of plant shoot lateral organs. PLoS Biol. 2019 doi: 10.1371/journal.pbio.3000560 Open Access

This Japanese study is led by Satoshi Naramoto and Junko Kyozuka and includes co-authors from the University of Oxford. They performed a mutant screen in the liverwort Marchantia polymorpha to identify the LATERAL ORGAN SUPRESSOR 1 (MpLOS1) gene, which regulates meristem maintenance and lateral organ development. Remarkably they showed this gene is also functions in the control of lateral organ development in rice, therefore demonstrating convergent evolution across plant lineages in the control of lateral organs.

Del Pozo A, Méndez-Espinoza AM, Romero-Bravo S, Garriga M, Estrada F, Alcaíno M, Camargo-Rodriguez AV, Corke FMK, Doonan JH, Lobos GA (2020) Genotypic variations in leaf and whole-plant water use efficiencies are closely related in bread wheat genotypes under well-watered and water-limited conditions during grain filling. Sci Rep. doi: 10.1038/s41598-019-57116-0 Open Access

Alejandro del Pozo leads this Chilean study that includes co-authors from Aberystwyth and NIAB. This large-scale glasshouse experiment looked at the effect of water deficit on the growth of 14 bread wheat genotypes. Measurement of multiple parameters revealed that plants face limitations to the assimilation process during grain filling due to natural senesce and water stress.

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: 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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GARNet Research Roundup: April 11th 2019

This edition of the GARNet Research Roundup is led by two papers from John Christie’s lab at the University of Glasgow. First is a study that looks at the function of the NPH3 protein during phototropism whilst the second paper is a collaboration with Mike Blatt’s group and has used an synthetic biology approach to increase plant biomass by altering stomatal conductance.

Third is a paper from the University Dundee and James Hutton Institute that looks at the extent of alternative splicing of long non-coding RNAs in response to cold stress.

The fourth paper is from Royal Holloway and defines the role of a MAP kinase module during meristem development. The fifth paper is led by Charles Spillane in Galway and includes Mary O’Connell at the University of Nottingham as a co-author and investigates the selective pressures that are applied to parentally imprinted genes.

The penultimate paper is from Aberystwyth and uses microCT imaging to determine grain parameters in wheat and barley whilst the final paper is from Queens Mary University of London looks at nonphotochemical quenching in Berteroa incana.

Sullivan S, Kharshiing E, Laird J, Sakai T, Christie J (2019) De-etiolation Enhances Phototropism by Modulating NON-PHOTOTROPIC HYPOCOTYL 3 Phosphorylation Status. Plant Physiol. doi: 10.1104/pp.19.00206

Open Access

Stuart Sullivan is first author on this work from John Christie’s lab at the University of Glasgow in which they investigate the functional significance of dephosphorylation of the NON-PHOTOTROPIC HYPOCOTYL 3 (NPH3) protein that occurs following activation of Phototropin receptor kinases. They show that plant greening (de-etiolation) enhances phototropic responses that are coincident with reduced NPH3 dephosphorylation and increased plasma membrane retention of the protein. They further investigate other genetic and environmental factors that impact NPH3 dephosphorylation, which allows young seedlings to maximise their establishment under changing light conditions.

Papanatsiou M, Petersen J, Henderson L, Wang Y, Christie JM, Blatt MR (2019) Optogenetic manipulation of stomatal kinetics improves carbon assimilation, water use, and growth. Science. doi: 10.1126/science.aaw0046

Maria Papanatsiou is lead author on this work from the University of Glasgow that occured in the labs of Mike Blatt and John Christie. They aimed to address a phenomonen that occurs during changing environmental conditions in which stomatal dynamics lag behind biochemical photosynthetic changes. This prevents plants from maximising their outputs due to inefficiencies in gas and water exchange. In this work they express a synthetic blue light-gated K+ channel BLINK1 in guard cells. This introduced a K+ conductance to these cells resulting in accelerated stomatal opening under light exposure and closing after irradiation. Ultimately they show that this significantly increases biomass without incurring a water use cost. This approach has clear potential for improving plant productivity under changing environmental conditions.

Calixto CPG, Tzioutziou NA, James AB, Hornyik C, Guo W, Zhang R, Nimmo HG, Brown JWS (2019) Cold-Dependent Expression and Alternative Splicing of Arabidopsis Long Non-coding RNAs. Front Plant Sci. doi: 10.3389/fpls.2019.00235

Open Access

Cristiane Calixto and John Brown from the University of Dundee and the James Hutton Institute lead this study into alternative splicing of lncRNAs in response to cold. This is a follow-up to their large scale scale study on the extent of alternative splicing in Arabidopsis.  The authors identified 135 lncRNA genes with cold-dependent differential expression (DE) and/or differential alternative splicing (DAS), some of which were highly sensitive to small temperature changes. This system identified a set of lncRNAs that could be targets for future research aimed at understanding how plants respond to cold and freezing stresses.

Dóczi R, Hatzimasoura E, Farahi Bilooei S, Ahmad Z, Ditengou FA, López-Juez E, Palme K, Bögre L (2019) The MKK7-MPK6 MAP Kinase Module Is a Regulator of Meristem Quiescence or Active Growth in Arabidopsis. Front Plant Sci. doi: 10.3389/fpls.2019.00202

Open Access

Robert Doczi is the first author on this UK, Hungarian and German collaboration that is led from Royal Holloway University of London. They use genetic approaches to show that the MKK7-MPK6 MAP kinase module is a suppressor of meristem activity. They use mkk7 and mpk6 mutants as well as overexpression lines to demonstrate that perturbation of the MAPK signaling pathway alters both shoot and root meristem development and plays important roles in the control of plant developmental plasticity.

Tuteja R, McKeown PC, Ryan P, Morgan CC, Donoghue MTA, Downing T, O’Connell MJ, Spillane C (2019) Paternally expressed imprinted genes under positive Darwinian selection in Arabidopsis thaliana. Mol Biol Evol. doi: 10.1093/molbev/msz063

Open Access

Reetu Tuteja from the National University of Ireland at Galway is first author on this paper that includes Mary O’Connell from the University of Nottingham. The authors used Arabidopsis to look at 140 endosperm-expressed genes that are regulated by genomic imprinting and found that they were evolving more rapidly than expected. This investigation was extended across 34 other plant species and they found that paternally, but not maternally imprinted genes were under positive selection, indicating that imprinted genes of different parental origin were subject to different selective pressures. This data supports a model wherein positive selection effects paternally-expressed genes that are under continued conflict with maternal sporophyte tissues.

Hughes N, Oliveira HR, Fradgley N, Corke FMK, Cockram J, Doonan JH, Nibau C (2019) μCT trait analysis reveals morphometric differences between domesticated temperate small grain cereals and their wild relatives. Plant J doi: 10.1111/tpj.14312

Open Access

Nathan Hughes and Candida Nibau at the Aberystwyth University lead this work that uses microCT imaging alongside novel image analysis techniques and mathematical modeling to assess grain size and shape across accessions of wheat and barley. They find that grain depth is a major driver of shape change and that it is also an excellent predictor of ploidy levels. In addition they have developed a model that enables the prediction of the origin of a grain sample from measurements of its length, width and depth.

Wilson S, Ruban AV (2019) Enhanced NPQ affects long-term acclimation in the spring ephemeral Berteroa incana. Biochim Biophys Acta Bioenerg. doi: 10.1016/j.bbabio.2019.03.005

This study is led by Sam Wilson and Alexander Ruban at QMUL and investigates nonphotochemical quenching in the Arabidopsis-relative Berteroa incana. They show that light tolerance and ability to recover from light stress is greatly enhanced in Berteroa compared to Arabidopsis. This is due to faster synthesis of zeaxanthin and a larger xanthophyll cycle (XC) pool available for deepoxidation. This result gives B.incana a greater capacity for protective NPQ allowing enhanced light-harvesting capability when acclimated to a range of light conditions. The authors suggest this short-term protection prevents the need for the metabolic toll of making long-term acclimations.

GARNet Research Roundup: March 21st 2019

This edition of the GARNet research roundup begins with a study from the John Innes Centre that investigates the role of auxin in the control of fruit development in Capsella.

Auxin is also a central focus of the next paper that is from SLCU, in which the authors characterise the role of different types of auxin transport during shoot development. The third paper, also from Cambridge, identifies a new function for members of the DUF579 enzyme family. The final paper from Cambridge reports on an outstanding citizen science project that looks at how different temperature and light conditions influence the growth of spring onions.

The next paper is from the University of Glasgow and investigates the role of the SNARE protein complex during vesicle transport in Arabidopsis.

The final two papers include authors from the University of Nottingham. Firstly Anthony Bishopp leads research that defines determinants of vascular patterning across plant species. Finally Don Grierson is a co-author on work that has identified novel signaling components involved in the response to hypoxia in Persimmon and Arabidopsis.

Dong Y, Jantzen F, Stacey N, Łangowski Ł, Moubayidin L, Šimura J, Ljung K, Østergaard L (2019) Regulatory Diversification of INDEHISCENT in the Capsella Genus Directs Variation in Fruit Morphology. Curr Biol. doi: 10.1016/j.cub.2019.01.057

Open Access

This research from Lars Ostergaard’s lab in the John Innes Centre is led by Yang Dong. The work is primarily conducted in Capsella and investigates the role of the INDEHISCENT (IND) protein in this plant, which has fruits that are morphologically distinct from those in Arabidopsis. Expression of CrIND controls fruit shape by influencing auxin biosynthesis leading to auxin accumulation in specific maxima that are localised to the fruit valves.

doi: 10.1016/j.cub.2019.01.057

van Rongen M, Bennett T, Ticchiarelli F, Leyser O (2019) Connective auxin transport contributes to strigolactone-mediated shoot branching control independent of the transcription factor BRC1. PLoS Genet. doi: 10.1371/journal.pgen.1008023

Open Access

Martin Van Rongen is the lead author on this research performed under the supervision of Ottoline Leyser at the Sainsbury Lab, Cambridge University. They investigate the hormonal signals that underpin the remarkable plasticity of shoot patterning, focusing on a genetic analysis of connective auxin transport (CAT), which moves the hormone across the stem (in contrast to up-down polar transport). Using multiple pin mutant plants, they show CAT is important in the regulation of strigolactone-mediated shoot branching. However shoot branching controlled by the BRANCHED1 transcription factor is reliant on the ABCB19 auxin export protein and is not significantly influenced by the activity of PIN proteins. Martin van Rongen discusses this paper on the GARNet YouTube channel.

Temple, H, Mortimer, JC, Tryfona, T, et al (2019) Two members of the DUF579 family are responsible for arabinogalactan methylation in Arabidopsis. Plant Direct.

Open Access

Henry Temple works with Paul Dupree at the University of Cambridge and leads this study that identifies a novel activity of two DUF579 enzymes in the methylation of glucuronic acid within highly glycosylated arabinogalactan proteins (AGPs). This differs from all other previously characterized DUF579 members that have been previously shown to methylate glucuronic acid within the cell wall component xylan.

Brestovitsky, A, Ezer, D (2019) A mass participatory experiment provides a rich temporal profile of temperature response in spring onions. Plant Direct. 2019; 3: 1– 11.

Open Access

This citizen science project led by Anna Brestovitsky and Daphne Ezer was performed in collaboration with the BBC Terrific Scientific program. In this study primary school students from across the UK recorded the growth of spring onions over a two-week period, which was then cross-referenced with detailed hourly meteorological data. This allowed the authors to discern the effect of minute temperature and light changes on plant growth and perhaps more importantly demonstrated that even the youngest researchers, when involved a well-designed citizen science project, can yield very useful data.

Zhang B, Karnik RA, Alvim JC, Donald NA, Blatt MR (2019) Dual Sites for SEC11 on the SNARE SYP121 Implicate a Binding Exchange during Secretory Traffic. Plant Physiol. doi: 10.1104/pp.18.01315

Open Access

Ben Zhang and Rucha Karnik are first authors on this paper that continues Mike Blatt‘s lab’s study of SNARE proteins, which are involved in vesicle trafficking. This study defines a new amino acid motif within SNARE SYP121 that is needed for the binding of the SEC11 protein but is not involved in binding plasma membrane K+ channels. This motif is essential for assembly of the entire SNARE complex yet does not influence the interaction of SYP121 with the uptake of K+ ions.

Mellor N, Vaughan-Hirsch J, Kümpers BMC, Help-Rinta-Rahko H, Miyashima S, Mähönen AP, Campilho A, King JR, Bishopp A (2019) A core mechanism for specifying root vascular patterning can replicate the anatomical variation seen in diverse plant species. Development. doi: 10.1242/dev.172411

Open Access

Nathan Mellor is first author on this work led by the lab of Anthony Bishopp at the University of Nottingham. The primary accomplishment of this work is in the development of a mathematical model that is able to predict the role of auxin in the specification of vascular patterning during embryonic development. This model has been tested through experimental interrogation of both transgenic Arabidopsis plants and in a range of other species with different vascular development patterns. Importantly they show that a heterologous auxin input might not be as critical in vascular development when compared to growth patterns that arise from spatial constraints. The authors show that this model has broad relevance to define early vascular patterning across plant species.

Zhu QG, Gong Z, Huang J, Grierson D, Chen KS, Yin XR (2019) High-CO2/hypoxia-responsive transcription factors DkERF24 and DkWRKY1 interact and activate DkPDC2 promoter. Plant Physiol. doi: 10.1104/pp.18.01552

Open Access

Don Greirson is a co-author on this Chinese-led study that identifies a set of transcription factors from Persimmon ((Diospyros kaki). These TFs are involved in responses to high CO2 and the authors show that their Arabidopsis orthologs play a similar role. The authors introduce a new response module that may be important during this key environmental response.

GARNet Research Roundup: November 1st 2018

This week’s GARNet research roundup again features papers on a variety of topics. First is work from the University of Leeds that investigates the physical properties of callose:cellulose hydrogels and the implication for cell wall formation. Second is work from the University of York that assesses the role of the HSP90.2 protein in control of the circadian clock. The third paper features GARNet committee member Sarah McKim and looks at the genetic control of petal number whilst the next paper from the Universities of Warwick and Glasgow includes a proteomic analysis of different types of secretory vesicles.

The next two papers look at different aspects of hormone signaling. Firstly Alistair Hetherington from the University of Bristol is a co-author on a study that looks at the role of the BIG protein whilst Simon Turner’s lab in Manchester investigates the role of ABA in xylem fibre formation.

The penultimate paper includes Lindsey Turnbull from the University of Oxford and looks at the stability of epialleles across 5 generations of selection. Finally is a paper that includes researchers from TSL in Norwich who have contributed to a phosphoproteomic screen to identify phosphorylated amino acids that influence the defence response.

Abou-Saleh R, Hernandez-Gomez M, Amsbury S, Paniagua C, Bourdon M, Miyashima S, Helariutta Y, Fuller M, Budtova T, Connell SD, Ries ME, Benitez-Alfonso Y (2018) Interactions between callose and cellulose revealed through the analysis of biopolymer mixtures. Nature Communications DOI: 10.1038/s41467-018-06820-y

Open Access
Radwa Abou-Saleh is lead author on this work from Yoselin Benitez-Alfonso’s lab at the University of Leeds. (1,3)-β-glucans such as callose play an important role in plant development yet their physical properties are largely unknown. This study analyses a set of callose:cellulose hydrogel mixtures as a proxy for different cell wall conditions. They show that callose:cellulose hydrogels are more elastic than those composed of only cellulose, providing evidence that the interactions between cellulose and callose are important for the structural features of cell walls.

Davis AM, Ronald J, Ma Z, Wilkinson AJ, Philippou K, Shindo T, Queitsch C, Davis SJ (2018) HSP90 Contributes To Entrainment of the Arabidopsis Circadian Clock via the Morning Loop. Genetics. doi: 10.1534/genetics.118.301586

Open Access
Amanda Davies is the first author on this study from Seth Davies’ lab at the University of York in which they assess the role of the molecular chaperone HSP90.2 on function of the circadian clock. The show hsp90.2-3 mutant plants have a lengthened circadian period with a specific defect in the morning. This data allows the authors to better understand the pathway through which HSP90.2 functions to entrain the circadian clock.

Monniaux M, Pieper B, McKim SM, Routier-Kierzkowska AL, Kierzkowski D, Smith RS, Hay A. The role of APETALA1 in petal number robustness. Elife. doi: 10.7554/eLife.39399

Open Access
GARNet committee member Sarah McKim is a co-author on this paper, that is led by Marie Monniaux, which includes research from her time at the University of Oxford. This work from the Hay lab in Cologne compares petal number in Arabidopsis thaliana, in which the number is invariant, and Cardamine hirsute, in which it varies. They show that petal number robustness can be attributed to the activity of the APETALA1 (AP1) floral regulator and that AP1 masks the activity of several genes in Arabidopsis but not in Cardamine.

Waghmare S, Lileikyte E, Karnik RA, Goodman JK, Blatt MR, Jones AME (2018) SNAREs SYNTAXIN OF PLANTS 121 (SYP121) and SYP122 mediate the secretion of distinct cargo subsets . Plant Physiol. doi: 10.1104/pp.18.00832

Open Access

This collaboration between the Universities of Glasgow and Warwick is led by Sakharam Waghmare, who works with Mike Blatt in Glasgow. This study uses proteomic approaches to characterise the secretory cargos within vesicles decorated with either of the SNARE proteins SYNTAXIN OF PLANTS 121 (SYP121) or SYP122. Genetic analysis suggests that SYP121 and SYP122 have redundant functions but this new research is able to identify cargo proteins that are either contained within both types of vesicle or that are specific to one or the other.

Zhang RX, Ge S, He J, Li S, Hao Y, Du H, Liu Z, Cheng R, Feng YQ, Xiong L, Li C, Hetherington AM, Liang YK (2018) BIG regulates stomatal immunity and jasmonate production in Arabidopsis. New Phytol. doi: 10.1111/nph.15568

Alistair Hetherington is a co-author on this China-based study led by Ruo‐Xi Zhang from Wuhan. This work adds to some recent interest in the BIG protein; in this study showing that it is involved in the interaction between JA and ethylene signaling during stress responses. In a complex set of interactions they show that the BIG protein differently alters opposing arms of the JA signaling pathway providing additional evidence that this protein is a key regulator of plant hormone signaling, albeit by a set of as yet unknown mechanisms.

Campbell L, Etchells JP, Cooper M, Kumar M, Turner SR. An essential role for Abscisic acid in the regulation of xylem fibre differentiation. Development. doi: 10.1242/dev.161992

This work from Simon Turner’s lab at the University of Manchester is led by Liam Campbell and identifies a novel role for ABA in the formation of xylem fibres during secondary thickening of the Arabidopsis hypocotyl. The action of ABA doesn’t alter the xylem:phloem ratio but rather the activity focuses on the formation of fibres within the already defined xylem tissue.

Schmid MW, Heichinger C, Coman Schmid D, Guthörl D, Gagliardini V, Bruggmann R, Aluri S, Aquino C, Schmid B, Turnbull LA, Grossniklaus U (2018) Contribution of epigenetic variation to adaptation in Arabidopsis. Nat Commun. doi: 10.1038/s41467-018-06932-5

Open Access
Lindsey Turnbull (University of Oxford) is a co-author on this paper from Ueli Grossniklaus’ group in Zurich. Marc Schmid is lead author of the study that investigates the inheritance of Arabidopsis epialleles over 5 generations during conditions of simulated selection. The authors show that variations in methylation state are subject to selection and do indeed contribute to adaptive responses

Kadota Y, Liebrand TWH, Goto Y, Sklenar J, Derbyshire P, Menke FLH, Torres MA, Molina A, Zipfel C, Coaker G, Shirasu K (2018) Quantitative phosphoproteomic analysis reveals common regulatory mechanisms between effector- and PAMP-triggered immunity in plants. New Phytol. doi: 10.1111/nph.15523

Members of Cyril Zipfel’s group at The Sainsbury lab in Norwich are co-authors on this paper led by Yasuhiro Kadota from the RIKEN in Yokohama. They use a phosphoproteomic screen to identify a set of newly identified phosphorylation sites on membrane-associated proteins involved in effector-triggered immunity (ETI). Some of these phosphosites overlap with those known to be important for pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI), indicating a convergence of signaling control of both these pathways to certain key residues.

GARNet Research Roundup: July 27th

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Published on: July 26, 2018

This GARNet research roundup includes papers that feature a number of different research areas. Firstly is work from Glasgow that investigates the photoactivation of the UVR8 light receptor. Second is work from the University of Cambridge that links the activity of the BIG protein to the circadian oscillator. The next paper has co-authors from Cambridge and looks at promotor sequences needed for expression in bundle sheath cells. The fourth paper from the University of Leeds documents an important role for peroxisomes in the drought response whilst the final manuscript includes co-authors from the University of Birmingham and looks at the role of the ASYNAPTIC4 protein during meiosis.!divAbstract

Díaz-Ramos LA, O’Hara A, Kanagarajan S, Farkas D, Strid Å, Jenkins GI. Difference in the action spectra for UVR8 monomerisation and HY5 transcript accumulation in Arabidopsis (2018) Photochem Photobiol Sci. doi: 10.1039/c8pp00138c

Open Access

Aranzazu Díaz-Ramos and Andrew O’Hara are co-first authors on this research from the University of Glasgow that investigates the activation of photomorphogenic responses by the UVR8 photoreceptor. They show that two distinct UVR8 responses, either the monomerisation of UVR homodimers or accumulation of HY5 responsive transcripts, occurs at different wavelengths.

Hearn TJ, Marti MC, Abdul-Awal SM, Wimalasekera R, Stanton CR, Haydon MJ, Theodoulou FL, Hannah MA, Webb AA (2018) BIG regulates dynamic adjustment of circadian period in Arabidopsis thaliana. Plant Physiology pp.00571.2018. doi: 10.1104/pp.18.00571

Open Access

Timothy Hearn works with Alex Webb at the University of Cambridge and in this paper characterises how the multi-functional BIG protein impacts the circadian clock. This gene was isolated in a forward genetics screen to identify signaling components that alter the response to nicotinamide, which acts as a brake on the circadian oscillator. This finding allows the authors to better understand how altering the circadian oscillator can affect appropriate phasing during different environmental conditions.

Kirschner S, Woodfield H, Prusko K, Koczor M, Gowik U, Hibberd JM, Westhoff P. Expression of SULTR2;2 in the Arabidopsis bundle sheath and vein cells is mediated by a positive regulator. J Exp Bot. 2018 Jul 19. doi: 10.1093/jxb/ery263

Open Access

Sandra Kirschner is first author on this German-led study that includes Helen Woodfield (now Cardiff University) and Julian Hibberd (University of Cambridge). They are interested in the mechanisms that restrict gene expression to bundle sheath cells in C3 plants with a longer view of understanding the biology of these cells in C4 plants. They analyse the vascular-restricted SULTR2;2 promotor and identified a short region that is necessary for its expression pattern. Importantly they show that this sequence is evolutionarily conserved across Brassicaceae and a distantly related C4 plant.

Ebeed HT, Stevenson S, Cuming AC, Baker A. Conserved and differential transcriptional responses of peroxisome associated pathways to drought, dehydration and ABA. J Exp Bot. 2018 Jul 19. doi: 10.1093/jxb/ery266

Open Access

Heba Ebeed is the lead author of this work conducted in Alison Baker’s lab at the University of Leeds. They take a comparative genomics approach to investigate the expression of peroxisome-localised genes in a moss (physcomitrella), monocot (wheat) and a dicot (arabidopsis). They show that members of three gene families are upregulated in each of these organisms following drought stress, demonstrating the importance of peroxisomes in this environmental response throughout plant evolution.

Chambon A, West A, Vezon D, Horlow C, De Muyt A, Chelysheva L, Ronceret A, Darbyshire AR, Osman K, Heckmann S, Franklin FCH, Grelon M (2018) Identification of ASYNAPTIC4, a component of the meiotic chromosome axis. Plant Physiol. pii: pp.01725.2017. doi: 10.1104/pp.17.01725

Chris Franklin and Alice Darbyshire from the University of Birmingham are co-authors on this French-led study that looks into the role of the ASYNAPTIC4 (ASY4) protein in the control of synapsis formation during meiosis. Plants without ASY4 activity have defective chromosomal axis formation and cannot undergo synapsis. Although the initiation of recombination is unaffected in asy4 mutants, later processes are altered, demonstrating the key role for ASY4 during meiosis

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