GARNet Research Roundup: June 12th 2019

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

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

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

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

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

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

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

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


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

Open Access

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

https://elifesciences.org/articles/42530

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

Open Access

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


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

Open Access

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

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

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

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


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

Open Access

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


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

Open Access

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

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

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

Open Access

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


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

Open Access

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

Open Access

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

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


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

Open Access

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

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

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

Open Access

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

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

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

Open Access

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


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

Open Access

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


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

Open Access

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

GARNet Research Roundup: May 27th 2019

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

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

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

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

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


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

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


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

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


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

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

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

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

Open Access

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


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

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


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

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

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

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

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


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

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


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

Open Access

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

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

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

Open Access

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

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

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

Open Access

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

GARNet Research Roundup: December 21st 2018

This bumper Festive Edition of the GARNet Research Roundup begins with two papers that have Beatriz Orosa-Puente as lead author following her work on SUMOylation with Ari Sadanandom at Durham. These papers looks at the role of SUMOylation in either auxin-mediated hydropatterning or in the defence response. Malcolm Bennett at Nottingham is a co-author on both papers and provided an audio description of the auxin-focused paper on the GARNet YouTube channel.

The next three papers are from the University of Edinburgh, the first that defines the role of HECT ubiquitin ligases in the defence response, the second that conducts a proteomic analysis of the GIGANTEA-interactome and the third that introduces a set of new tools for inducible gene expression in Arabidopsis roots.

The sixth and seventh papers feature authors from the John Innes Centre. Martin Howard and Caroline Dean are corresponding authors on a multi-scale analysis of the factors that control FLC expression whilst Myriam Charpentier’s lab has contributed to an investigation about LINC complexes in Medicago.

David Salt and Levi Yant from Nottingham lead the next paper that provides an analysis of the genetic determinants of adaptation to different salt conditions.

The final three papers are from Cambridge. Firstly Ian Henderson is the corresponding author on work that looks at crossover rates in specific disease resistance loci. Second is work from the Paszkowski lab at SLCU that introduces a new method for the analysis of active retrotransposons in crop plants whilst finally James Locke, also at SLCU, uses the method of distributed delays to simplify the complexity of biological network models.


Orosa-Puente B, Leftley N, von Wangenheim D, Banda J, Srivastava AK, Hill K, Truskina J, Bhosale R, Morris E, Srivastava M, Kümpers B, Goh T, Fukaki H, Vermeer J, Vernoux T, Dinneny JR, French AP, Bishopp A, Sadanandom A , Bennett MJ (2018) Roots branch towarss water by post-translational modification of the transcription factor ARF7 Science DOI: 10.1126/science.aau3956

Orosa B, Yates G, Verma V, Srivastava AK, Srivastava M, Campanaro A, De Vega D, Fernandes A, Zhang C, Lee J, Bennett MJ, Sadanandom A (2018) SUMO conjugation to the pattern recognition receptor FLS2 triggers intracellular signalling in plant innate immunity. Nat Commun. doi: 10.1038/s41467-018-07696-8 Open Access

http://science.sciencemag.org/content/362/6421/1407

Beatriz Orosa-Puente is the lead author on two publications that have arisen from a collaboration between the labs of Ari Sadanandom at Durham and Malcolm Bennett at Nottingham. In the first paper Beatriz is co-first author with Nicola Leftley and Daniel von Wangenheim in research that links the auxin response, SUMOylation and the search for water. They reveal a novel mechanism for controlling the auxin response in which SUMOylation regulates the interaction between the ARF7 and IAA3 proteins. In turn this controls asymmetric expression of genes downstream of ARF7 and determines how different parts of the root response to the presence or absence of water.

The second paper continues with the Sadanandom lab’s focus on SUMOylation, in this case during control of the defence response. They show that SUMO is conjugated to the FLAGELLIN-SENSITIVE 2 (FLS2) receptor that senses bacterial flagellin. This releases downstream cytoplasmic effectors and enhances the immune response. The authors show that there is additional complexity to this system by also showing that flagellin induces degradation of the deSUMOylating enzyme Desi3a, thus allowing the plant to make a stronger immune response.


Furniss JJ, Grey H, Wang Z, Nomoto M, Jackson L, Tada Y, Spoel SH (2018) Proteasome-associated HECT-type ubiquitin ligase activity is required for plant immunity. PLoS Pathog. doi: 10.1371/journal.ppat.1007447 Open Access

James Furniss is the lead author on this paper from the lab of current GARNet Chairman Steven Spoel at the University of Edinburgh. They show that a family of HECT domain-containing ubiquitin protein ligases (UPLs) are involved in defence responses mediated by the hormone salicylic acid (SA). Upl3 mutants show reprogramming of the entire SA transcriptional response and they are unable to establish immunity against a hemi-biotrophic pathogen, demonstrating their key role in this important process.


https://febs.onlinelibrary.wiley.com/doi/abs/10.1002/1873-3468.13311

Krahmer J, Goralogia GS, Kubota A, Zardilis A, Johnson RS, Song YH, MacCoss MJ, LeBihan T, Halliday KJ, Imaizumi T, Millar AJ (2018) Time-resolved Interaction Proteomics of the GIGANTEA Protein Under Diurnal Cycles in Arabidopsis. FEBS Lett. doi: 10.1002/1873-3468.13311 Open Access

This paper is a collaboration between researchers in Edinburgh and Seattle for which Johanna Krahmer is lead author. They used a proteomic approach to identify proteins that interacted with a tagged-version of the key circadian regulator GIGANTEA. They successfully identified the novel transcription factor CYCLING DOF FACTOR (CDF)6. CDF6 was confirmed as interacting with GI and playing a role in the control of flowering. The time series of proteomic data produced in this study is available for use by any other interested researcher.

http://proteomecentral.proteomexchange.org/cgi/GetDataset?ID=PXD006859


Machin FQ, Beckers M, Tian X, Fairnie A, Cheng T, Scheible WR, Doerner P (2018) Inducible reporter/driver lines for the Arabidopsis root with intrinsic reporting of activity state. Plant Journal. doi: 10.1111/tpj.14192

Frank Qasim Machin is the lead author on this Technical Advance from Peter Doerner’s lab at the University of Edinburgh. They have developed a Gateway-based system for tightly controlled inducible expression across all the major cell types of the Arabidopsis roots. They have fully characterised reference driver lines that can be adapted for specific experimental requirements and hope that this contributes towards enhancing reproducibility of qualitative and quantitative analyses.


https://www.sciencedirect.com/science/article/pii/S2405471218304368?via%3Dihub

Antoniou-Kourounioti RL, Hepworth J, Heckmann A, Duncan S, Qüesta J, Rosa S, Säll T, Holm S, Dean C, Howard M (2018) Temperature Sensing Is Distributed throughout the Regulatory Network that Controls FLC Epigenetic Silencing in Vernalization. Cell Syst. doi: 10.1016/j.cels.2018.10.011 Open Access

This work results from the successful collaboration between Caroline Dean and Martin Howard at the John Innes Centre and includes Rea Antoniou-Kourounioti and Jo Hepworth as co-first authors. They attempt to understand how the upregulation of VERNALIZATION INSENSITIVE3 (VIN3) and silencing of FLOWERING LOCUS C (FLC) is controlled during fluctuating temperatures over month-long time scales. They develop a mathematical model that integrates information from hour, day and month-long datasets to show that temperature is sensed across the entire regulatory network and not focussed on specific nodes. This allows a final effect to only be realised once all parts of the network have been appropriately changed. This model with matches new field data and therefore represents a predictive tool for the effects of climate change on plant growth.


Newman-Griffis AH, Del Cerro P, Charpentier M, Meier I (2018) Medicago LINC complexes function in nuclear morphology, nuclear movement, and root nodule symbiosis Plant Physiol. http://www.plantphysiol.org/content/early/2018/12/10/pp.18.01111 Open Access
Pablo del Cerro and Myriam Charpentier at the John Innes Centre are co-authors on this paper from Iris Meier’s lab at The Ohio State University. They identify and characterise the Linker of Nucleoskeleton and Cytoskeleton (LINC) family of nucleus-membrane-associated proteins. They show that, as in Arabidopsis, these proteins are required for nucleus movement in the root tip cells of Medicago truncatula and that they are an important contributor to nodulation. Both Iris and Myriam are members of the INDEPTH consortium that includes researchers who study this broad area of plant cell biology.


https://www.pnas.org/content/early/2018/12/11/1816964115.long

Busoms S, Paajanen P, Marburger S, Bray S, Huang XY, Poschenrieder C, Yant L, Salt DE (2018) Fluctuating selection on migrant adaptive sodium transporter alleles in  coastal Arabidopsis thaliana. Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1816964115 Open Access

This UK-Sino-Spanish collaboration is led by David Salt and Levi Yant at the University of Nottingham. Silvia Busoms is the first author on the study that investigates the genetics of adaptive salt tolerance in a cohort of 77 individuals grown across a salinity gradient in a coastal region of Catalonia. By integrating their data with the 1135 genomes project they are able to trace the ancestry of these populations and define that growth in high salt conditions is associated with increased expression of the high-affinity K+ transporter (HKT1;1). This demonstrates that this gene plays a key role in the adaptation to salt stress.


Serra H, Choi K, Zhao X, Blackwell AR, Kim J, Henderson IR. Interhomolog polymorphism shapes meiotic crossover within the Arabidopsis RAC1 and RPP13 disease resistance genes (2018) PLoS Genet. doi: 10.1371/journal.pgen.1007843 Open Access

This UK-Korean collaboration is led by the Heidi Serra and Ian Henderson at the University of Cambridge. They mapped the meiotic crossover hotspots that are located within the RAC1 and RPP13 disease resistance genes in Arabidopsis. They assessed these locations in plants with altered recombination rates and surprisingly showed that these effects have little impact at the RAC1 loci. Therefore they show that chromosome location and local chromatin environment are important for regulation of crossover activity. Overall they demonstrate that interhomolog divergence is important in shaping recombination within plant disease resistance genes and crossover hotspots.


Cho J, Benoit M, Catoni M, Drost HG, Brestovitsky A, Oosterbeek M, Paszkowski J (2018) Sensitive detection of pre-integration intermediates of long terminal repeat retrotransposons in crop plants. Nat Plants. doi: 10.1038/s41477-018-0320-9

Open Access with link: rdcu.be/bdLjy

For the second edition in succession, the GARNet research roundup features work from Jerzy Paszkowski’s lab at SLCU. In this case Jungnam Cho is lead author on work that has developed a new technique called ALE-seq (amplification of LTR of eclDNAs followed by sequencing) for analysis of transposon-rich genomes from crop plants. Through characterisation of extrachromosomal linear DNA (eclDNA), ALE-seq allows the identification of active transposons. The authors use this technique in both rice and tomato and successfully identify a set of developmentally regulated transposable elements. This paper includes details of a bioinformatic pipeline that is adapted for ALE-seq data analyses, the scripts for which are available on GitHub.


Tokuda IT, Akman OE, Locke JCW. Reducing the Complexity of Mathematical Models for the Plant Circadian Clock by Distributed Delays (2018) J Theor Biol. doi: 10.1016/j.jtbi.2018.12.014

This UK-Japanese study includes James Locke at SLCU as corresponding author. They address the challenge of integrating an increasing number of parameters into large biological network models. Their system of study is the Arabidopsis circadian clock and they use the method of distributed delays to simplify the complexity of existing models. They demonstrate this effect by updating a model that explains the regulation of the PRR9 and PRR7 genes by LHY. They use recent experimental data and revise the previous model to show that it is more accurately reproduces the LHY-induction experiments of core clock genes. As stated they show that overall use of distributed delays facilitates the optimisation and reformulation of genetic network models.

GARNet Research Roundup: October 10th 2018

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Published on: October 10, 2018

This edition of the GARNet research roundup begins with a paper from Jose Gutierrez-Marcos’ lab in Warwick that investigates the functional significance of inherited epigenetics marks in clonally propagated plants. Second is work from Sara Simonini and Lars Ostergaard (John Innes Centre) that defines a domain in the ETTIN protein important for the auxin response. Next is work from SLCU from Siobhan Braybrook and Henrik Jonsson that experimentally defines and models the role of cell wall composition in anisotropic hypocotyl growth. The fourth paper is from Jonathan Jones’ lab (TSL, Norwich) that adds to our understanding of the activity of the RRS1-R-RPS4 NLR immune complex.

The final three papers are each from the University of Edinburgh and look at different aspects of the relationship between light quality and the circadian clock. First is a paper from Karen Halliday’s lab that investigates the role of PHYA; next Andrew Millar is a co-author on a manuscript that looks at control of FT expression during seasonally realistic conditions. Finally Ference Nagy and Mirela Domijan (University of Liverpool) co-author a paper that assesses the role of HY5 in the response to blue-light.


Wibowo A, Becker C, Durr J, Price J, Spaepen S, Hilton S, Putra H, Papareddy R, Saintain Q, Harvey S, Bending GD, Schulze-Lefert P, Weigel D, Gutierrez-Marcos J (2018) Partial maintenance of organ-specific epigenetic marks during plant asexual reproduction leads to heritable phenotypic variation. Proc Natl Acad Sci U S A doi: 10.1073/pnas.1805371115

http://www.pnas.org/content/early/2018/09/06/1805371115.long

Open Access
Anjar Wibowo and Claude Becker are first authors on this UK-German collaboration from the labs of Jose Gutierrez-Marcos (University of Warwick) and Detlef Weigel (Max Planck Institutem, Tübingen). In this work they clonally propagate Arabidopsis and show that organ-specific epigenetic marks are maintained across generations. Interestingly these changes are then maintained through multiple rounds of sexual reproduction. These epigenetic marks provide heritable molecular and physiological phenotypes that can alter the response to pathogens, allowing progeny to maintain a beneficial epigenome that was generated in their parents.


Simonini S, Mas PJ, Mas CMVS, Østergaard L, Hart DJ (2018) Auxin sensing is a property of an unstructured domain in the Auxin Response Factor ETTIN of Arabidopsis thaliana. Sci Rep. doi: 10.1038/s41598-018-31634-9

https://www.nature.com/articles/s41598-018-31634-9

Open Access

This UK-France collaboration is led by Sara Simonini from the John Innes Centre and continues the Ostergaard lab’s work on the role of the auxin response factor ETTIN in the auxin response. In this paper they analyse the C-terminal ETT specific domain (ES domain) across plant lineages, showing that it does not directly bind auxin but could functional response to a dose response of auxin in a Y2H assay. Understanding more about this ES domain will increase our understanding of auxin sensing by ETTIN and more broadly about auxin-dependent gene regulation.


Bou Daher F, Chen Y, Bozorg B, Clough J, Jönsson H, Braybrook SA. Anisotropic growth is achieved through the additive mechanical effect of material anisotropy and elastic asymmetry. Elife.  doi: 10.7554/eLife.38161

https://elifesciences.org/articles/38161

Open Access

Firas Bou Daher is the first author on work from Siobhan Braybrook’s lab conducted both in the Sainsbury Lab Cambridge University and at its new home in California. In this work they look at anisotropic growth in the Arabidopsis hypocotyl and the relationship between cellulose orientation and pectin deposition in the control of this process. They provide experimental evidence that growth parameters are influenced by pectin biochemistry in processes that begin immediately after germination.


Ma Y, Guo H, Hu L, Martinez PP, Moschou PN, Cevik V, Ding P, Duxbury Z, Sarris PF, Jones JDG (2018) Distinct modes of derepression of an Arabidopsis immune receptor complex by two different bacterial effectors. Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1811858115

Yan Ma and Hailong Guo are lead authors on this study from Jonathan Jones’ lab at The Sainsbury Lab, Norwich. They perform a detailed examination of the RRS1-R-RPS4 NLR protein complex, which is necessary to respond to at the bacterial effectors, AvrRps4 and PopP2. Deletion of a WRKY transcription factor domain in the RRS1-R protein causes constitutive activation of the defense response, indicating that this domain maintains the complex in an inactive state in the absence of pathogens. Indeed AvrRps4 does interact with this WRKY domain but interestingly PopP2 activation requires interaction with a longer C-terminal extension of RRS1-R. This demonstrates that although these bacterial effectors are recognised by the same complex the interactions occurs in a subtly but functionally distinct ways.


Seaton DD, Toledo-Ortiz G, Ganpudi A, Kubota A, Imaizumi T, Halliday KJ (2018) Dawn and photoperiod sensing by phytochrome A. Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1803398115

Open Access

This research from Karen Halliday’s lab in Edinburgh is led by Daniel Seaton and provided a detailed assessment of the role of phytochrome A (phyA) in photoperiod sensing, which is defined as the relationship between the circadian clock and external light signals. They show that PHYA activity, controlled by the transcription factors, PIF4 and PIF5, is a key regulator of morning activity, particularly in short photoperiods. PHYA protein accumulates during the night and responds to light by promoting a burst of gene expression that prepares the plant for the upcoming daylight and places this light receptor as a key detector of dawn.


Song YH, Kubota A, Kwon MS, Covington MF, Lee N, Taagen ER, Laboy Cintrón D, Hwang DY, Akiyama R, Hodge SK, Huang H, Nguyen NH, Nusinow DA, Millar AJ, Shimizu KK, Imaizumi T (2018) Molecular basis of flowering under natural long-day conditions in Arabidopsis. Nat Plants. doi: 10.1038/s41477-018-0253-3

Andrew Millar is a co-author on this US-led paper that investigates the circadian regulation of the Arabidopsis florigen gene FLOWERING LOCUS T (FT) within an annual context, showing that during the spring FT shows a morning peak is absent in their usual lab experiments. By adjusting growth-room conditions to mimic natural seasonal variations they show that phytochrome A and EARLY FLOWERING 3 regulate morning FT expression by stabilizing the CONSTANS protein. This manuscript highlights the importance of providing seasonal-specific conditions in order to understand field-relevant regulation of plant growth.


Hajdu A, Dobos O, Domijan M, Bálint B, Nagy I, Nagy F, Kozma-Bognár L. ELONGATED HYPOCOTYL 5 mediates blue light signalling to the Arabidopsis circadian clock (2018) Plant J. doi: 10.1111/tpj.14106

Ferenc Nagy (University of Edinburgh) is a co-author on this Hungarian-led study that looks the effect of light quality on the function of the key signaling hub transcription factor ELONGATED HYPOCOTYL 5 (HY5). They show that hy5 mutants show shorter period rhythms in blue but not in red light or darkness. Even though the pattern and level of HY5 alters its binding to downstream promotor elements, subsequent gene expression is only altered in a few genes. In collaboration with Mirela Domijan (University of Liverpool) https://www.liverpool.ac.uk/mathematical-sciences/staff/mirela-domijan/ they model this response to suggest that clock feedback mechanisms mask HY5-induced changes. Ultimately they show that HY5 is important in decoding the blue:red mix of white light and that it at least partially informs activity of the circadian oscillator.

GARNet Research Roundup: April 11th 2018

This weeks GARNet research roundup begins with a microscopy-based study led by Lorenzo Frigerio from the University of Warwick that investigates the origin of Protein Storage Vacuoles. The second paper from John Doonan at Aberystwyth University looks at how differential splicing of cyclin-dependent Kinase G1 effects the thermosensory response. Reiner van de Hoorn from Oxford leads the next paper that characterises the use of activity-based protein profiling (ABPP) to identify novel α-glycosidases in model and non-model plants. Simon McQueen-Mason from York is corresponding author of the next paper that identified a new QTL from Brachypodium that is involved in cell wall formation. The fifth paper is led by Anthony Dodd from Bristol and characterises the role of the SnRK1 complex in hypocotyl elongation whilst the penultimate manuscript from Julia Davies’s lab in Cambridge performs patch clamp analysis of dorn1 mutant plants. The final paper from Brendan Davies at the University of Leeds characterises the SMG kinase, a gene that is lacking from the Arabidopsis genome, in Physcomitrella patens.


http://www.plantphysiol.org/content/early/2018/03/19/pp.18.00010.long

Feeney M, Kittelmann M, Menassa R, Hawes C, Frigerio L. Protein storage vacuoles originate from remodelled pre-existing vacuoles in Arabidopsis thaliana (2018) Plant Physiol. 2018 Mar 19. pii: pp.00010.2018. doi: 10.1104/pp.18.00010 Open Access

This collaboration between the Universities of Warwick and Oxford Brookes is led by Lorenzo Frigerio and Chris Hawes. They have investigated the origin of seed Protein Storage Vacuoles (PSV) using a two-pronged approach using confocal and immunoelectron microscopy. They looked at embryo development as well as in leaf cells that have been reprogrammed for embryonic cell fate by overexpression of the LEAFY COTYLEDON2 TF. These studies indicate that PSVs are formed following the reprogramming of pre-existing embryonic vacuole (EV) rather than from de novo assembly.


https://onlinelibrary.wiley.com/doi/abs/10.1111/tpj.13914

Cavallari N, Nibau C, Fuchs A, Dadarou D, Barta A, Doonan JH. The Cyclin Dependent Kinase G group defines a thermo-sensitive alternative splicing circuit modulating the expression of Arabidopsis ATU2AF65A (2018) Plant J. doi: 10.1111/tpj.13914 Open Access

John Doonan (Aberystwyth University) is the corresponding author on this UK-Austrian collaboration that presents the role of the cyclin-dependent Kinase G1 (CDKG1) in thermosensing in Arabidopsis. Ambient temperature change causes altered gene expression of the spliceosome component, ATU2AF65A. Interestingly the CDKG1 gene is differentially spliced and to produces two protein isoforms that are both needed to complement the expression of ATU2AF65A across a temperature range. This alternative splicing is dependent on CDKG2 and CYCLIN L1 and is a novel control mechanism in the temperature control response.


Husaini AM, Morimoto K, Chandrasekar B, Kelly S, Kaschani F, Palmero D, Jiang J, Kaiser M, Ahrazem O, Overkleeft HS, van der Hoorn RAL (2018) Multiplex fluorescent, activity-based protein profiling identifies active α-glycosidases and other hydrolases in plants. Plant Physiol. pii: pp.00250.2018. doi: 10.1104/pp.18.00250 Open Access

Renier Van de Hoorn (University of Oxford) leads this pan-european study that uses novel cyclophellitol aziridine probes that label α-glycosidase enzymes. They identified two novel α-glycosidases in Arabidopsis as well as using the technique in non-model saffron crocus. Finally they showed that this multiplex fluorescent labelling in combination with probes for serine hydrolases and cysteine proteases can be used to identify changes in hydrolase activity in response to pathogen infection.


Whitehead C, Ostos Garrido FJ, Reymond M, Simister R, Distelfeld A, Atienza SG, Piston F, Gomez LD, McQueen-Mason SJ (2018) A glycosyl transferase family 43 protein involved in xylan biosynthesis is associated with straw digestibility in Brachypodium distachyon. New Phytol. doi: 10.1111/nph.15089 Open Access

Simon McQueen-Mason (University of York) leads this study that use QTL mapping to identify a gene in Bracypodium that is involved in cell wall architecture, which might then be a target to develop plants with improved cellulose digestibility. This glycosyl transferase family (GT) 43 protein is an orthologue of Arabidopsis IRX14, which is involved in xylan biosynthesis. When RNAi was used to reduce expression of this gene the resulting plants showed increased digestibility, indicating that this BdGT43A will be a good target for future breeding plans.


Wang L, Wilkins KA, Davies JM (2018) Arabidopsis DORN1 extracellular ATP receptor; activation of plasma membrane K(+) -and Ca(2+) -permeable conductances New Phytol. 2018 Mar 25. doi: 10.1111/nph.15111. Open Access

This letter to New Phytologist from the lab of Julia Davis (University of Cambridge) outlines some experiments to determine whether the DORN1 plasma membrane receptor is responsible for transmitting a signal from extracellular ATP (eATP). They performed patch clamp analysis on isolated protoplasts and showed that DORN1 is involved in the activation of Ca+ and K+ pumps by eATP as, in contrast to wildtype, dorn1 mutant protoplast showed no voltage changes after incubation with eATP.


Simon NML, Sawkins E, Dodd AN. Involvement of the SnRK1 subunit KIN10 in sucrose-induced hypocotyl elongation (2018) Plant Signal Behav. 27:1-9. doi: 10.1080/15592324.2018.1457913.

Anthony Dodd (University of Bristol) is the corresponding author of this follow-on study from one that previously featured on the GARNet YouTube channel. This study measures sucrose-induced hypocotyl elongation in two T-DNA mutants of the SnRK1 subunit KIN10 gene. These mutants had altered responses to sucrose leading to the hypothesis that the SnRK1 complex suppresses hypocotyl elongation in the presence of external sugar.


Lloyd JPB, Lang D, Zimmer AD, Causier B, Reski R, Davies B (2018) The loss of SMG1 causes defects in quality control pathways in Physcomitrella patens. Nucleic Acids Res. doi: 10.1093/nar/gky225 Open Access

Brendan Davis (University of Leeds) is the corresponding author on research that investigates the role of the SMG1 kinase during nonsense-mediated mRNA decay (NMD) in the moss Physcomitrella patens. This kinase plays a critical role in animals but as it is not present in Arabidopsis, its function is not well studied in plants. However moss smg mutants show expression changes in genes involved in a variety of processes indicating that NMD is a common control mechanism in moss. In addition these plants have increased susceptibility to DNA damage, which suggests that the SMG1 kinase is a key player in quality control mechanisms in plants.

https://academic.oup.com/nar/advance-article/doi/10.1093/nar/gky225/4955258

GARNet Research Roundup: March 29th

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Published on: March 29, 2018

This edition of the GARNet research roundup begins with an analysis of the CELLULOSE SYNTHASE COMPLEX led by Simon Turner in Manchester. Next are two papers from Ian Henderson at Cambridge who, in collaboration with Rob Martienssen in the USA, has investigated the epigenetic factors that control meiotic recombination. Next are two papers led by Hugh Nimmo (Glasgow) who is researching alternative splicing of the LATE ELONGATED HYPOCOTYL transcript. Marc Vendrell and Karl Oparka at the University of Edinburgh are co-authors in the next paper that investigates the binding specificity of the AtSUC2 protein. The seventh paper includes David Salt (Nottingham) as a co-author in an investigation in the plants response to zinc. The final three papers are methods papers on gravitropism, ChIP-Seq and calcium sensing from Nottingham University, SLCU and the John Innes Centre respectively.


Kumar M, Mishra L, Carr P, Pilling M, Gardner P, Mansfield SD, Turner SR (2018) Exploiting CELLULOSE SYNTHASE (CESA) class-specificity to probe cellulose microfibril biosynthesis. Plant Physiol. doi: 10.1104/pp.18.00263 Open Access

Simon Turner (University of Manchester) leads this study that investigates the subunit specificity of the CELLULOSE SYNTHASE COMPLEX, which is composed of many CESA components. Mutant cesa plants were used to probe the specificity of these subunits. Overall the authors found that CESA classes have similar roles in determining cellulose microfibril structure but that the rates of cellulose synthesis might be altered in a subunit-specific manner.


Choi K,, Zhao X, Tock AJ, Lambing C, Underwood CJ,, Hardcastle TJ, Serra H, Kim J, Cho HS, Kim J, Ziolkowski PA, Yelina NE, Hwang I, Martienssen RA, Henderson IR (2018) Nucleosomes and DNA methylation shape meiotic DSB frequency in Arabidopsis thaliana transposons and gene regulatory regions. Genome Res. doi: 10.1101/gr.225599.117
The research groups of Ian Henderson (University of Cambridge) and Rob Martienssen (CSHL) co-lead back-to-back papers that investigate the factors that influence meiotic recombination frequencies. The Henderson led-paper focuses on the position of the SPO11 topoisomerase and the epigenetic factors, such as H3K4me3 and DNA methylation that reside in those areas. They discovered some surprising relationships between SPO11 binding and different transposon classes.


Underwood CJ, Choi K, Lambing C, Zhao X, Serra H, Borges F, Simorowski J, Ernst E, Jacob Y, Henderson IR, Martienssen RA (2018) Epigenetic activation of meiotic recombination near Arabidopsis thaliana centromeres via loss of H3K9me2 and non-CG DNA methylation. Genome Res. doi: 10.1101/gr.227116.117

Open Access

The Martienssen–led paper focuses on epigenetic marks, such as H3K9me2 and non-CG DNA methylation that reside at pericentromeric regions. By altering the distribution of these marks, the amount of pericentrometric recombination can be changed and that the number of double stranded breaks increase in H3K9me2/non-CG mutants.


James AB, Sullivan S, Nimmo HG (2018) Global spatial analysis of Arabidopsis natural variants implicates 5’UTR splicing of LATE ELONGATED HYPOCOTYL in responses to temperature. Plant Cell Environment. doi: 10.1111/pce.13188

James AB, Calixto CPG, Tzioutziou NA, Guo W, Zhang R, Simpson CG, Jiang W, Nimmo GA, Brown JWS, Nimmo HG (2018) How does temperature affect splicing events? Isoform switching of splicing factors regulates splicing of LATE ELONGATED HYPOCOTYL (LHY). Plant Cell Environ. doi: 10.1111/pce.13193

The first of these back-to-back papers is led by Hugh Nimmo (Glasgow) in a study that characterises a set of 5’UTRs in the LATE ELONGATED HYPOCOTYL (LHY) gene and how they change in response to temperature. This is linked to a correlation of how these LHY haplotypes are global distributed.

The second paper is an extension of this study and includes Hugh Nimmo (Glasgow) and John Brown (JHI, Dundee) as co-corresponding authors. They that show RNA-binding splicing factors (SFs) are necessary for temperature-induced changes in the LHY transcript. LHY might be considered a molecular thermostat whose splicing can response to changes as little as 2°C.


De Moliner F, Knox K, Reinders A, Ward J, McLaughlin P, Oparka K, Vendrell M (2018) Probing binding specificity of the sucrose transporter AtSUC2 with fluorescent coumarin glucosides. J Exp Bot. doi: 10.1093/jxb/ery075 Open Access

Marc Vendrell and Karl Oparka (University of Edinburgh) are the corresponding authors on this bioimaging study that probes the specificity of the AtSUC2 phloem sucrose transporter. They use structural varieties in coumarin glucosides to precisely define the binding characteristics of AtSUC2.


Chen ZR, Kuang L, Gao YQ, Wang YL, Salt DE, Chao DY (2018) AtHMA4 Drives Natural Variation in Leaf Zn Concentration of Arabidopsis thaliana. Front Plant Sci. doi: 10.3389/fpls.2018.00270

Open Access

David Salt (University of Nottingham) is a co-author on this Chinese study that characterises the role of the Heavy Metal-ATPase 4 (HMA4) in the respond to zinc.


Muller L, Bennett MJ, French A, Wells DM, Swarup R (2018) Root Gravitropism: Quantification, Challenges, and Solutions. Methods Mol Biol. doi: 10.1007/978-1-4939-7747-5_8

Ranjan Swarup (University of Nottingham) leads this methods paper that describes techniques for the automated measurement of root gravitropic responses.


Cortijo S, Charoensawan V, Roudier F, Wigge PA (2018) Chromatin Immunoprecipitation Sequencing (ChIP-Seq) for Transcription Factors and Chromatin Factors in Arabidopsis thaliana Roots: From Material Collection to Data Analysis. Methods Mol Biol. doi: 10.1007/978-1-4939-7747-5_18

Phillip Wigge (SLCU) leads this methods paper that outlines the technical details for the now common and important technique of ChIP-Seq from Arabidopsis roots.


Kelner A, Leitão N, Chabaud M, Charpentier M, de Carvalho-Niebel F (2018) Dual Color Sensors for Simultaneous Analysis of Calcium Signal Dynamics in the Nuclear and Cytoplasmic Compartments of Plant Cells. Front Plant Sci. doi: 10.3389/fpls.2018.00245 Open Access

Miriam Charpentier (John Innes Centre) is a co-author on this work that uses fluorescent protein-based Ca2+ sensors, the GECOs, to successfully monitor the calcium response to a range of biotic and abiotic elicitors. These GECO-based sensors represent an exciting new tool for the study of calcium dynamics.

Arabidopsis Research Roundup: March 9th

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Published on: March 9, 2018

This Arabidopsis Research Roundup has five papers that includes two from the John Innes Centre and two from the University of Edinburgh. Firstly Kristen Bomblies’s group at the JIC have investigated the relationship between temperature and meiotic recombination rates. Secondly Veronica Grieneisen and Stan Maree have developed a mathematical model to characterise cell morphologies taken from a 2D image. Andrew Miller from Edinburgh is a co-corresponding author on a study that shows how the Arabidopsis proteome changes in different photoperiods. In the fourth paper Peter Doerner is a co-author on work that looks at the phosphate starvation response. Finally researchers from Bristol and Nottingham contribute to an investigation into a novel genetic component that controls auxin-induced root hair development.


Lloyd A, Morgan C, Franklin C, Bomblies K (2018) Plasticity of Meiotic Recombination Rates in Response to Temperature in Arabidopsis. Genetics. doi: 10.1534/genetics.117.300588

Open Access

Kristen Bomblies (John Innes Centre) leads this study that investigates the influence of temperature on meiotic recombination rate. They show that in Arabidopsis the number of crossovers positively correlates with increasing temperature. However the mechanistic explanation for the increase at higher temperatures remains opaque as, in contrast to findings from other plants, synaptonemal complex length negatively correlates with temperature.


Sánchez-Corrales YE, Hartley M, van Rooij J, Marée AFM, Grieneisen VA (2018) Morphometrics of complex cell shapes: Lobe Contribution Elliptic Fourier Analysis (LOCO-EFA). Development. doi: 10.1242/dev.15677

http://dev.biologists.org/content/early/2018/02/08/dev.156778.long

Open Access

Veronica Grieneisen and Stan Maree (John Innes Centre) lead this study that has developed the Lobe Contribution Elliptical Fourier Analysis (LOCO-EFA) method. This generates meaningful descriptors from a 2D image of cells that can then be linked to morphological features. This tool allows for the efficient phenotyping of cell morphologies that they demonstrate by analysing images of Arabidopsis leaf pavement cells. They extend this analysis to larger populations where they used LOCO-EFA to predict how cell shapes change when they move into a more crowded space.


Seaton DD, Graf A, Baerenfaller K, Stitt M, Millar AJ, Gruissem W (2018) Photoperiodic control of the Arabidopsis proteome reveals a translational coincidence mechanism. Mol Syst Biol. doi: 10.15252/msb.20177962 Open Access

http://onlinelibrary.wiley.com/doi/10.15252/msb.20177962/abstract

Andrew Miller (University of Edinburgh) is the corresponding author on this collaboration with German and Swiss colleagues that compares the Arabidopsis proteome across four photoperiods. They shows coordinated changes across the proteome, most notably at longer photoperiods in the abundance of proteins involved in photosynthesis and metabolism. They show higher translation rates during the day that correspond with the increased RNA abundance that is a characteristic of circadian rhythms. This ‘translational coincidence’ describes the alignment of higher translation rates with high transcript levels and they assigned a mathematical model in an attempt to explain this phenomenon.


Hanchi M, Thibaud MC, Légeret B, Kuwata K, Pochon N, Beisson F, Cao A, Cuyas L, David P, Doerner P, Ferjani A, Lai F, Li-Beisson Y, Mutterer J, Philibert M, Raghothama KG, Rivasseau C, Secco D, Whelan J, Nussaume L, Javot H (2018) The phosphate fast-responsive genes PECP1 and PPsPase1 affect phosphocholine and phosphoethanolamine content. Plant Physiol. doi: 10.1104/pp.17.01246 Open Access

Peter Doerner (University of Edinburgh) is a co-author on this global study that characterises the phosphate starvation-mediated induction of the HAD-type phosphatases PPsPase1 (AT1G73010) and PECP1 (AT1G17710). They show that expression of these genes closely follows phosphate status but that their activity does not alter phospate content. The role of these proteins is to control phosphocholine and phosphoethanolamine content, which is a output of changing phosphate conditions. The authors conclude that expression of these genes can be an excellent molecular marker for the phosphate starvation response.


www.cell.com/current-biology/fulltext/S0960-9822(18)30083-6

Schoenaers S, Balcerowicz D, Breen G, Hill K, Zdanio M, Mouille G, Holman TJ, Oh J, Wilson MH, Nikonorova N, Vu LD, De Smet I, Swarup R, De Vos WH, Pintelon I, Adriaensen D, Grierson C, Bennett MJ, Vissenberg K (2018) The Auxin-Regulated CrRLK1L Kinase ERULUS Controls Cell Wall Composition during Root Hair Tip Growth. Current Biology doi: 10.1016/j.cub.2018.01.050

This Belgian-led study includes contributions from Claire Greirson’s and Malcolm Bennett’s labs in Bristol and Nottingham respectively. They investigate the role of the ERULUS (ERU) protein, an auxin-induced receptor-like kinase, during the development of root hairs. ERU localises to the apical root hair plasma membrane and regulates cell wall composition by altering pectin dynamic. The authors conclude that ERU is a key regulator of auxin-mediated control of root hair development.

Arabidopsis Research Roundup: February 22nd 2018

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Published on: February 22, 2018

This edition of the Arabidopsis Research roundup beings with a study from SLCU that provides a molecular context to the changes that occur at graft junctions. Second is a study from Edinburgh that reports on the findings of a citizen science plant phenotyping project. Third are two studies from the John Innes Centre that follow-on from previous studies. These characterise the molecular response to seasonal transitions and the factors that control floral development.

The fifth paper is led by Chris Hawes at Oxford Brookes and characterises a novel sub-group of ER localized reticulon proteins. The next paper from the University of Sheffield looks at the whole plant response to changing global carbon dioxide concentrations. The seventh paper from Bristol and York also broadly looks at CO2 but this time at the molecular factors that control stomatal closure in response to both ABA and CO2 signals. Christine Foyer (Leeds) is a co-author on the penultimate paper that characterises the role of ascorbic acid in hormone signaling whilst the final paper from Julian Hibberd at the University of Cambridge analyses a regulatory element that contributes to the evolutionary transition to C4 photosynthesis.


Melnyk CW, Gabel A, Hardcastle TJ, Robinson S, Miyashima S, Grosse I, Meyerowitz EM (2018) Transcriptome dynamics at Arabidopsis graft junctions reveal an intertissue recognition mechanism that activates vascular regeneration. Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1718263115 Open Access
This research was led by Charles Melynk during this time working with Elliot Meyerowitz at SLCU. Grafting is an important classic and contemporary technique in plant biology and this study investigates the gene expression changes that occur on either side of a graft junction. They show asymmetry changes in gene expression on either side of a graft that include an increase in vascular initiation but only in grafted tissues and not in those that are cut and then separated. This study provides an exciting insight into the molecular changes that occur during tissue grafting.


Giuffrida MV, Chen F, Scharr H, Tsaftaris SA (2018) Citizen crowds and experts: observer variability in image-based plant phenotyping. Plant Methods. doi: 10.1186/s13007-018-0278-7 Open Access

This UK, German and Italian study is led by Sotirios Tsaftaris at the University of Edinburgh and reports on a fascinating citizen science study that evaluated the ability of experts and non-experts to use plant phenotyping software. They demonstrate that non-experts can be effectively involved in plant phenotyping annotation tasks given enough statistical power and if the study is suitably designed.


Hepworth J, Antoniou-Kourounioti RL, Bloomer RH, Selga C, Berggren K, Cox D, Collier Harris BR, Irwin JA, Holm S, Säll T,Howard M, Dean C (2018) Absence of warmth permits epigenetic memory of winter in Arabidopsis. Nat Commun. doi: 10.1038/s41467-018-03065-7 Open Access

Caroline Dean and Martin Howard (John Innes Centre) lead this study that further characterise the relationship between the VERNALIZATION INSENSITIVE3 (VIN3) an FLOWERING LOCUS C (FLC) genes in two separate thermosensory processes that monitor long term temperature changes. They suggest that the regulatory strategies currently employed by plants might become less effective as the climate becomes more variable and will have a knock-on effect on plant growth and productivity.


Simonini S, Stephenson P, Østergaard L (2018) A molecular framework controlling style morphology in Brassicaceae. Development. doi: 10.1242/dev.158105 Open Access
Lars Ostergaard (John Innes Centre) leads this study that characterises how the activity of five transcription factors (TF) integrate with auxin signaling in the control of gynoecium development. The auxin response factor ETTIN is a central controller of this relationship across members of the Brassicaceae and that variation in an ETTIN sub-domain effects TF affinities, interaction strength and gynoecium morphology


Kriechbaumer V, Maneta-Peyret L, Fouillen L, Botchway SW, Upson J, Hughes L, Richardson J, Kittelmann M, Moreau P, Hawes C

The odd one out: Arabidopsis reticulon 20 does not bend ER membranes but has a role in lipid regulation. Sci Rep. doi: 10.1038/s41598-018-20840-0

This study is led by Chris Hawes (Oxford Brookes) and continues his labs work on the plant ER. They are working on a subgroup of reticulons, which are ER membrane proteins, that have an extended N-terminal domain. Three members of this subgroup show different localisation patterns that indicates that along their sequences are similar they might play different cellular roles.


Williams A, Pétriacq P, Schwarzenbacher RE, Beerling DJ, Ton J (2018) Mechanisms of glacial-to-future atmospheric CO2 effects on plant immunity. New Phytol. doi: 10.1111/nph.15018 Open Access
This article from the University of Sheffield uses Arabidopsis to investigate the impact that changing climatic CO2 concentrations might have on plant immunity. The authors performed a global analysis on the response to sub-ambient and elevated CO2 and found that both changes causes alterations to salicyclic acid or jasmonic acid response pathways. However these responses are not always opposite, revealing new insights in the response to changing CO2 concentrations.


 

Isner JC, Begum A, Nuehse T, Hetherington AM, Maathuis FJM (2018) KIN7 Kinase Regulates the Vacuolar TPK1 K+ Channel during Stomatal Closure. Curr Biol. doi: 10.1016/j.cub.2017.12.046.

This is collaborative work between the Universities of York and Bristol and analyses factors that control stomatal closure. They show the TPK1 vacuolar K+ channel is important for ABA and CO2 mediated closure and that the function of this protein is regulated by the KIN7 receptor-like kinase. These activities result in potassium release from the vacuole leading to osmotic changes that contribute to stomatal closure.


Caviglia M, Mazorra Morales LM, Concellón A, Gergoff Grozeff GE, Wilson M, Foyer CH, Bartoli CG (2018) Ethylene signaling triggered by low concentrations of ascorbic acid regulates biomass accumulation in Arabidopsis thaliana. Free Radic Biol Med. doi: 10.1016/j.freeradbiomed.2018.01.032

Christine Foyer (University of Leeds) is a co-author on this research showing that a defect in ascorbic acid production leads to elevated levels of the hormone ethylene as well as having a wider impact on the control of growth-mediating hormone signalling. This result indicates that the cellular redox buffer AA is a significant contributor to hormone signalling pathways.


Reyna-Llorens I, Burgess SJ, Reeves G, Singh P, Stevenson SR, Williams BP, Stanley S, Hibberd JM (2018) Ancient duons may underpin spatial patterning of gene expression in C4 leaves.Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1720576115

Julian Hibberd (University of Cambridge) is the corresponding author on this study that is part of his labs overarching aim of discovering what is necessary to transfer C4 photosynthesis into C3 plants. As part of this work they are searching for master regulator sequences that have allowed for the multiple independent evolution of C4 photosynthesis. They have identified a regulatory duon that is a pair of cis-elements located in coding sequences of genes preferentially expressed in bundle sheath cells of C4 leaves and are also present in C3 plants and algae. Therefore they discuss how C4 plants have co-opted these regulatory elements and how it might be exploited in future molecular engineering projects.

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