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: April 29th 2019

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

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


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

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


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

Open Access

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


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

Open Access

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

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

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

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

Open Access

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

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

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

Open Access

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

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


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

Open Access

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

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


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

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

Open Access

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

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

GARNet Research Roundup: March 7th 2019

This edition of the GARNet research roundup begins with a study into the genetic basis of fertility in barley led by Sarah McKim from Dundee. Second is a study from Oxford and Leicester that characterizes the proteolytic control of chloroplast import. The third paper from Levi Yant’s group at JIC and Nottingham that attempts to discover the influence of polyploidism on population genomic effects whilst the fourth paper from Juliet Coates’ lab in Birmingham uses the growth of Arabidopsis to assess the potential of algal biomass as a biofertiliser. The next two papers include co-authors from Oxford and Warwick respectively and investigate different factors that control seed viability in Arabidopsis and Brassica oleracea. The final paper includes Seth Davies from York as a co-author on a study that looks at control of the circadian clock in field-grown Arabidopsis.


Zwirek M, Waugh R, McKim SM (2019) Interaction between row-type genes in barley controls meristem determinacy and reveals novel routes to improved grain. New Phytol. doi: 10.1111/nph.15548

Open Access

Current GARNet committee members Sarah McKim is the leader of this study in which first author is Monica Zwirek. They investigate the mechanism through which the barley VRS genes contribute to spikelet fertility. They undercover the epistatic relationship between five VRS genes that explains how they contribute to controlling fertility of lateral spikelets. Importantly they demonstrate that various vrs mutant combinations improve fertility in a variety of ways, information that will be useful during the generation of new varieties of barley.

https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.15548

Ling Q, Broad W, Trösch R, Töpel M, Demiral Sert T, Lymperopoulos P, Baldwin A, Jarvis RP (2019) Ubiquitin-dependent chloroplast-associated protein degradation in plants. Science. doi: 10.1126/science.aav4467

Qihua Ling and William Broad are the first authors on this study from the Universities of Oxford and Leicester. They investigate the role of proteolysis in the functional control of chloroplast-envelope translocases, which are required for the transport of proteins from nucleus-encoded genes into the chloroplast. They identify two newly characterised proteins that function in the same pathway as the known ubiquitin E3 ligase SP1. These novel proteins, SP2 and CDC48, are both required for the movement of ubiquitinated proteins from the chloroplast outer envelope membrane (OEM) into the cytosol, where they are degraded by the proteolytic machinery. This process of chloroplast-associated protein degradation (CHLORAD) maintains tight control of the activity of OEM proteins and is essential for organelle function.

http://science.sciencemag.org/content/363/6429/eaav4467.long

Monnahan P, Kolář F, Baduel P, Sailer C, Koch J, Horvath R, Laenen B, Schmickl R, Paajanen P, Šrámková G, Bohutínská M, Arnold B, Weisman CM, Marhold K, Slotte T, Bomblies K, Yant L (2019) Pervasive population genomic consequences of genome duplication in Arabidopsis arenosa. Nat Ecol Evol. doi: 10.1038/s41559-019-0807-4.

Patrick Monnahan at the John Innes Centre is first author on this study from the Yant lab that has recently moved to the University of Nottingham. In this collaboration with colleagues in the US, Austria, Sweden, the Czech Republic and Slovakia, they have performed large scale sequencing on 39 populations of Arabidopsis arenosa. These plants have differing levels of ploidy and they are attempting to understand how ploidy effects population genomics. They demonstrate that the ploidy effects are subtle but significant and that masking of deleterious mutations, faster substitution rates and interploidy introgression will likely impact the evolution of populations where polyploidy is common.


Ghaderiardakani F, Collas E, Damiano DK, Tagg K, Graham NS, Coates J (2019) Effects of green seaweed extract on Arabidopsis early development suggest roles for hormone signalling in plant responses to algal fertilisers. Sci Rep. doi: 10.1038/s41598-018-38093-2

Open Access

This work from the Coates lab at the University of Birmingham is led by Fatemeh Ghaderiardakani and looked into the potential of algal extracts as biofertiliser. They showed that at >0.1%, extracts taken from the common green seaweed Ulva intestinalis inhibit Arabidopsis seed germination and root elongation. At lower concentrations primary root elongation was promoted albeit with a complete loss of lateral root formation. Elemental analysis allows the authors to suggest that this effect was mediated via a novel mechanism involving aluminium. Overall the authors caution against the use of algal biofertilisers due to potential unforeseen negative effects on plant growth.


Viñegra de la Torre N, Kaschani F, Kaiser M, van der Hoorn RAL, Soppe WJJ, Misas Villamil JC (2019) Dynamic hydrolase labelling as a marker for seed quality in Arabidopsis seeds. Biochem J. doi: 10.1042/BCJ20180911.

GARNet Committee member Renier van der Hoorn is a co-author on this German-led study that investigates how the activity of seed-localised proteases can affect Arabidopsis seed germination. This study has clear real-world application regarding the storage of economically important seed stocks. They show that vacuolar processing enzymes (VPEs) become more active during aging whilst the activity of serine hydrolases declines alongside seed quality. This information has allowed the authors to develop protease-activity-based markers that will provide information about seed quality.


Schausberger C, Roach T, Stöggl WM, Arc E, Finch-Savage WE, Kranner I (2019) Abscisic acid-determined seed vigour differences do not influence redox regulation during ageing. Biochem J. doi: 10.1042/BCJ20180903

William Finch-Savage from the University of Warwick is a co-author on this Austrian-led study that looks at the effect of aging on the quality of Brassica oleracea seeds stored at two oxygen concentrations. Higher O2 causes a more rapid decrease in seed quality through aging yet in contrast aging did not alter the impact of the hormone ABA on seed viability. This study enables the authors to uncover two mechanisms that control seed quality that appear to act through different mechanisms.


Rubin MJ, Brock MT, Davis SJ, Weinig C (2019) QTL Underlying Circadian Clock Parameters Under Seasonally Variable Field Settings in Arabidopsis thaliana G3 (Bethesda). doi: 10.1534/g3.118.200770

Open Access

Seth Davies from the University of York is a co-author on this study led by Matthew Rubin from the University of Wyoming. They looked at the growth of Arabidopsis thaliana recombinant inbred lines grown in field conditions and found an extremely nuanced relationship regarding how QTLs that influence the circadian clock respond to environmental conditions. For example the authors showed that plant growth in June, July and September is controlled by different QTL architecture, demonstrating the complex regulation of the circadian clock in these field growth plants.

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.

Arabidopsis Research Roundup: December 8th.

This weeks Research Roundup begins with two papers from the University of Edinburgh on very different topics of Arabidopsis research. Firstly Alistair McCormick and Sofirtios Tsaftaris introduce a new low-cost phenotyping platform whilst Gerben Ooijen’s group has analysed the role of SUMOylation in the control of the circadian clock. The next three papers each involve wide UK collaborations and either look at plant nutrient composition (Nottingham, Dundee, York), the role of N-end rule pathway in the control of seed storage mobilisation (Rothamsted, Nottingham, Oxford, Birmingham, Cambridge) or the development of a new tool for the study of phloem sieve elements (Leeds, Rothamsted, Cambridge, Newcastle). The penultimate paper from Daniel Zilbermann (JIC) highlights the global mechanisms of methyltransferase function in Arabidopsis and mice whilst the final paper from Alexandre Ruban (QMUL) and co-authors continues his groups work to unpick the specifics of NPQ.


Dobrescu A, Scorza LCT, Tsaftaris SA, McCormick AJ (2017) A “Do-It-Yourself” phenotyping system: measuring growth and morphology throughout the diel cycle in rosette shaped plants. Plant Methods. doi: 10.1186/s13007-017-0247-6

Open Access

University of Edinburgh colleagues Alistair McCormick and Sofirtios Tsaftaris lead this work that presents a low cost phenotyping system for the analysis of the growth rate and phenotypic characteristics of Arabidopsis thaliana rosettes. The software that they have developed allows the accurate segmentation of multiple rosettes within a single image and overall offers a straightforward solution for automated phenotyping across a range of growth environments.


Hansen LL, van den Burg HA, van Ooijen G (2017) Sumoylation Contributes to Timekeeping and Temperature Compensation of the Plant Circadian Clock. J Biol Rhythms. doi: 10.1177/0748730417737633

Gerben van Ooijen (University of Edinburgh) is the corresponding author of this work that has identified SUMOylation as a novel mechanism of regulating circadian clock genes in Arabidopsis. Plants with defects in sumoylation have altered circadian periods that exhibit incorrect temperature compensation. Overall these results indicate that sumoylation importantly buffers clock function in response to changing temperatures.


Alcock TD, Havlickova L, He Z, Bancroft I, White PJ, Broadley MR, Graham NS (2017) Identification of Candidate Genes for Calcium and Magnesium Accumulation in Brassica napus L. by Association Genetics. Front Plant Sci. doi: 10.3389/fpls.2017.01968

Open Access

Neil Graham and Martin Broadley (University of Nottingham) are the corresponding authors of this study that has taken advantage of the Brassica napus Associative Transcriptomes RIPR diversity panel developed by Ian Bancroft’s lab in York. Novel loci involved with an altered response to calcium and magnesium were identified in B.napus before mineral composition was analysed in Arabidopsis mutants defective in orthologous genes. The analysed plants exhibited alteration in mineral composition, meaning that the associated Brassica loci might be targets for future breeding strategies aimed at improving plant nutrient compositions.


Zhang H, Gannon L, Hassall KL, Deery MJ, Gibbs DJ, Holdsworth MJ, van der Hoorn RAL, Lilley KS, Theodoulou FL (2017) N-terminomics reveals control of Arabidopsis seed storage proteins and proteases by the Arg/N-end rule pathway. New Phytol. doi: 10.1111/nph.14909

Freddie Theodoulou (Rothamsted Research) is the corresponding author of this research that involved a collaboration with colleagues in Cambridge, Birmingham, Nottingham and Oxford. They have performed a proteomic analysis on etiolated seedlings to identify those proteins designated for degradation by the N-end rule pathway. They analysed prt6 mutant plants that lack the function of the E3 ligase PROTEOLYSIS6 (PRT6) and discovered that N-terminal peptides from 45 protein groups were upregulated in this mutant, corresponding to the equivalent downregulation of several known N-end rule proteases. Overall the authors show that PRT6 plays an important role in the regulation of seed storage mobilisation in young seedlings and is therefore a possible future target to manipulate the plant responses to adverse environmental conditions. Dr Kirsty Hassall, a statistician at Rothamsted, is an author on this paper and in the latest edition of the GARNish newsletter explains how she interacts with plant scientists during her work.


Torode TA, O’Neill RE, Marcus SE, Cornuault V, Pose-Albacete S, Lauder RP, Kracun SK, Gro Rydahl M, Andersen MCF, Willats WGT, Braybrook SA, Townsend BJ, Clausen MH, Knox JP (2017) Branched pectic galactan in phloem-sieve-element cell walls: implications for cell mechanics. Plant Physiol. doi: 10.1104/pp.17.01568 Open Access

Paul Knox (University of Leeds) is the corresponding author of this study that includes contributions from researchers at SLCU, Newcastle and Rothamsted. This work is based around the development of a monoclonal antibody, LM26 that is able to recognize a β-1,6-galactosyl substitution of β-1,4-galactan. LM26 has allowed the identification of this unusual branched galactan that is specific to phloem elements and the authors hope that it can be a useful tool in future studies on the biology of phloem elements


Lyons DB, Zilberman D (2017) DDM1 and Lsh remodelers allow methylation of DNA wrapped in nucleosomes. Elife. doi: 10.7554/eLife.30674 Open Access

Daniel Zilberman has recently moved to the John Innes Centre and is the lead author of this work that was conducted when he was working in US. This research is a cross-kingdom analysis showing that nucleosome-free DNA is the preferred target for methyltransferases in both Arabidopsis and mice, and that nucleosomes appear to be a barrier to the function of these enzymes. Furthermore they demonstrate that linker-specific methylation that is usually absent in Arabidopsis can be introduced by removal of histone H1. This shows that flowering plants still possess this ability despite its loss, during the evolution of H1, over a billion years ago.


Tutkus M, Chmeliov J, Rutkauskas D, Ruban AV, Valkunas L (2017) Influence of the Carotenoid Composition on the Conformational Dynamics of Photosynthetic Light-Harvesting Complexes. J Phys Chem Lett. doi: 10.1021/acs.jpclett.7b02634

Alexandre Ruban (QMUL) is a co-author on this study that investigates the role that carotenoid composition plays in the control of Non-photochemical quenching (NPQ), a mechanism that protects the photosynthetic apparatus from light-damage. Arabidopsis mutants with differing carotenoid compositions were analysed for the dynamics of the conformation switches that occur during NPQ. Interestingly they show that LHCII has robust function  that is resistant to different carotenoid concentrations.

Arabidopsis Research Roundup: July 3rd.

The Arabidopsis Research Roundup returns this week with selection of publications from institutions across the UK. Firstly George Bassel (Birmingham) leads a study that investigates the integration of inductive signals in the embryonic root. Secondly a group from the Oxford Brookes plant science group look into the literal linkages between the golgi apparatus and ER. Thirdly John Christie (Glasgow) and co-workers define a new variant of the phototropin receptor. Next Caroline Dean and Martin Howard (John Innes Centre) collaborate on work that defines the relationship between FLC, COOLAIR and cell size. The fifth paper is led by members of SLCU and investigates the regulatory influence of the Evening Complex of the circadian clock. The penultimate paper features work from Alison Smith’s group at the JIC that looks at dynamics of starch accumulation and degradation. Lastly is research from NIAB that defines the pathogeniticity of novel UK isolates of the fungal pathogen Verticillium longisporum.


Topham AT, Taylor RE, Yan D, Nambara E, Johnston IG, Bassel GW (2017) Temperature variability is integrated by a spatially embedded decision-making center to break dormancy in Arabidopsis seeds. PNAS

http:/​/​dx.​doi.​org/10.1073/pnas.1704745114

Open Access

George Bassel (University of Birmingham) leads this study that identifies a decision making centre in the embryonic root that is defined by the intimate interaction between the hormones abscisic acid (ABA) and gibberellin (GA). The activity of this ‘decision centre’ is linked to both hormone transport and changes in temperature, the overall output of which is the decision to promotes seed germination or to delay until more favourable environmental conditions.

George discusses this paper on the GARNet YouTube channel.



Osterrieder A, Sparkes IA, Botchway SW, Ward A, Ketelaar T, de Ruijter N, Hawes C (2017) Stacks off tracks: a role for the golgin AtCASP in plant endoplasmic reticulum-Golgi apparatus tethering. J Exp Bot. http:/​/​dx.​doi.​org/10.1093/jxb/erx167

Open Access

Anne Osterrieder and Chris Hawes (Oxford Brookes University) continue their work that looks at  the cellular dynamics of the golgi apparatus with this study that identifies the AtCASP protein as a important component that tethers the golgi to the ER. They use live-cell imaging to visualise golgi formation in cells that have different levels of AtCASP, allowing the authors to confirm that ER-golgi tethering is disrupted without the activity of this protein.


Petersen J, Inoue SI, Kelly SM, Sullivan S, Kinoshita T, Christie JM (2017) Functional Characterization of a Constitutively Active Kinase Variant of Arabidopsis Phototropin 1

J Biol Chem. http:/​/​dx.​doi.​org/10.1074/jbc.M117.799643

Open Access

John Christie (University of Glasgow) collaborates with Japanese colleagues to identify a novel variant of the phototropin receptor. Study of this variant allows a greater understanding regarding the mode of action of this protein under different light conditions, as controlled by phosphorylation.


Ietswaart R, Rosa S, Wu Z, Dean C, Howard M (2017) Cell-Size-Dependent Transcription of FLC and Its Antisense Long Non-coding RNA COOLAIR Explain Cell-to-Cell Expression Variation. Cell Syst. http:/​/​dx.​doi.​org/10.1016/j.cels.2017.05.010

Open Access

Martin Howard and Caroline Dean (John Innes Centre) again collaborate on research that analyses the mode of regulation of FLC. They dissect RNA dynamics of FLC expression by single molecule in situ RNA fluorescence, showing that this is dependent on the presence of the antisense COOLAIR regulatory DNA. In the absence of COOLAIR they show FLC expression has a linear relationship with cell size but in the presence of the antisense transcript, FLC expression decreases with cell size. Overall they demonstrate FLC expression is tightly dependent on the presence of the antisense COOLAIR transcript.


Ezer D, Jung JH, Lan H, Biswas S, Gregoire L, Box MS, Charoensawan V,, Cortijo S, Lai X,, Stöckle D, Zubieta C, Jaeger KE, Wigge PA (2017) The evening complex coordinates environmental and endogenous signals in Arabidopsis. Nat Plants.

http:/​/​dx.​doi.​org/10.1038/nplants.2017.87

Free to view with this URL.

Phil Wigge and Katja Jaeger (SLCU) lead this study that investigates how the evening complex of the circadian clock coordinates the expression of numerous important growth regulators. This genome wide regulation is determined by temperature and concides with the binding of phytochrome B, which provides a cellularly mechanism of this level of environmental control.


Fernandez O, Ishihara H, George GM, Mengin V, Flis A, Sumner D, Arrivault S, Feil R, Lunn JE, Zeeman SC, Smith AM, Stitt M (2017) Foliar starch turnover occurs in long days and in falling light at the end of the day. Plant Physiol. http:/​/​dx.​doi.​org/10.1104/pp.17.00601

Open Access

On this paper Alison Smith (John Innes Centre) is a co-corresponding author together with Mark Stitt from the Max Planck Institute for Molecular Plant Physiology in Potsdam. They continue their work to investigate the dynamics of starch metabolism in Arabidopsis leaves. Broadly they show the rate of starch accumulation corresponds to the photosynthetic rate whilst degradation is linked to correct functioning of the circadian clock. They investigate this process in more detail by determining how the rate of starch degradation alters dependent on the time after dawn.


Depotter J, Rodriguez-Moreno L, Thomma BP, Wood T (2017) The emerging British Verticillium longisporum population consists of aggressive Brassica pathogens. Phytopathology http:/​/​dx.​doi.​org/10.1094/PHYTO-05-17-0184-R

Tom Wood (NIAB) is the corresponding author of this study that characterises four new UK isolates of the fungal pathogen Verticillium longisporum. The pathogenticity of V.longisporum was tested on Arabidopsis alongside three other Brassica crops. They demonstrate that the UK isolates were unusually aggressive yet this was not consistent across all Brassica cultivars with different fungal lineages showing different effects on oil seed rape, cabbage or cauliflower.

Arabidopsis Research Roundup: July 27th

Each of the papers in this Arabidopsis Research Roundup involves the response to different stimuli. Giles Johnson at Manchester provides an audio description of work that has discovered a novel mechanism of cold sensing whilst Gordon Simpson and John Brown from Dundee are contributors to work that has interrogated the sugar signaling pathway. Finally is a study from Warwick that has identified novel loci involved in ABA signaling and seed vigour.

Dyson BC, Miller MA, Feil R, Rattray N, Bowsher C, Goodacre R, Lunn JE, Johnson GN (2016) FUM2, a cytosolic fumarase, is essential for acclimation to low temperature in Arabidopsis thaliana Plant Physiology http://dx.doi.org/10.1104/pp.16.00852

Open Access

From http://www.plantphysiol.org/content/early/2016/07/20/pp.16.00852.long
From http://www.plantphysiol.org/content/early/2016/07/20/pp.16.00852.long

Giles Johnson (Manchester) is the corresponding author on this UK-German collaboration that looks at the mechanisms by which plants sense the low temperatures that cause significant phenotypic changes. GC-MS showed that fumarate is a key component in the cold tolerance response and that the activity of the FUM2 enzyme is responsible for accumulation of fumaric acid. Plants that lack FUM2 activity show significant alteration in gene expression and metabolite profile following a cold treatment and in particularly are unable to acclimate photosynthesis at lower temperatures. Therefore this study introduces a novel component of the temperature sensing apparatus, which might have broad significance for attempts to develop crops with an improved cold response.

Giles kindly provides an audio description of this work, which includes an overview into cold acclimation of photosynthesis. This includes an excellent ‘stress-ball’ analogy! (Apologies for pen-clicks :/).

 

Carvalho RF, Szakonyi D, Simpson CG, Barbosa IC, Brown JW, Baena-González E, Duque P (2016) The Arabidopsis SR45 Splicing Factor, a Negative Regulator of Sugar Signaling, Modulates SNF1-Related Protein Kinase 1 (SnRK1) Stability The Plant Cell http://dx.doi.org/10.1105/tpc.16.00301

From http://www.plantcell.org/content/early/2016/07/19/tpc.16.00301.abstract
From http://www.plantcell.org/content/early/2016/07/19/tpc.16.00301.abstract

Gordon Simpson and John Brown (James Hutton Institute) are contributors to this Portuguese-led study that investigates the role of the SR45 splicing factor in sugar signaling. In sr45-1 mutants they show that glucose-feeding causes increased levels of the energy-sensing SNF1-Related Protein Kinase 1 (SnRK1) yet without increasing its gene expression. Concomitantly the hypersensitivity of sr45-1 mutants is rescued in plants with reduced levels of SnRK1. The authors discovered that the mechanistic link between these genes involves SR45-1 regulating the alternative splicing of the 5PTase13 gene, which encodes an inositol polyphosphate 5-phosphatase that interacts with SnRK1 in vivo. In wildtype plants 5PTase13 modulates proteasomal-mediated degradation of SnRK1 and therefore a perturbation of this process in sr45-1 explains this defect in sugar-sensing.

Morris K, Barker GC, Walley PG, Lynn JR, Finch-Savage WE (2016) Trait to gene analysis reveals that allelic variation in three genes determines seed vigour. New Phytol. http://dx.doi.org/10.1111/nph.14102 Open Access

Bill Finch-Savage is the corresponding author on this study from the Warwick University that uses Brassica oleracea natural variation to identify novel loci involved in seed vigour. The discovered QTL was termed Speed of Germination (SOG1) and contained two genes, BoLCVIG2, a homologue of the alternative-splicing regulator (AtPTB1) and BoLCVIG1, which has unknown function. Transfer of these alleles into Arabdopsis causes alterations in seed germination, which is also observed in mutants of the equivalent Arabidopsis genes (At3g01060, At3g01150). Furthermore an additional discovered QTL encodes the Reduced ABscisic Acid 1 (RABA1) gene, which influences ABA content and seed vigour. Therefore this mapping strategy has discovered three genes that promote seed vigour resulting from alterations in ABA content and sensitivity.

Arabidopsis Research Roundup: April 1st.

This weeks Arabidopsis Research Roundup contains an eclectic mix of investigations. Firstly is a study from Peter Unwin that investigates the molecular factors that control interactions between plants and nematode parasites. Secondly is a study led by John Christie that investigates the factors that control hypocotyl curvature. Thirdly is a fascinating proof-of-concept synbio-style study from Rothamstead Research where an algal gene is transferred into Arabidopsis in the hope of developing a phytomediation-based solution to heavy metal contamination. Fourthly is a study from David Bass that catalogues protist species that feed on leaf-microorganisms whilst finally John Carr heads a study that compares RNA-dependent RNA polymerases from Arabidopsis and Potato.

Eves-van den Akker S, Lilley CJ, Yusup HB, Jones JT, Urwin PE (2016) Functional C-terminally encoded plant peptide (CEP) hormone domains evolved de novo in the plant parasite Rotylenchulus reniformis. Mol Plant Pathol. http://dx.doi.org/10.1111/mpp.12402).CEP1

This study is a collaboration between researchers at the Universities of Dundee and Leeds, led by Peter Unwin. The focus of the paper is the interaction of Plant-Parasitic Nematodes (PPNs) with their plant hosts. PPNs stimulate redifferentiation of vascular tissues to form ‘feeding structures’ that benefit the parasite. This process is mediated by a diverse family of effector proteins termed C-terminally Encoded Peptide plant hormone mimics (CEPs). This study investigates the CEPs from the nematode Rotylenchulus reniformis and suggests that these peptides evolved de novo in this organism. They show that the activity of a synthetic peptide corresponding to RrCEPs causes a reduction in primary root elongation whilst upregulating a set of genes including the nitrate transporter AtNRT2.1. The authors propose that CEPs evolved in R. reniformis to allow sustained biotrophy by upregulating a specific set of feeding-responsive genes and by limiting the size of the feeding site produced. This study represents an exciting introduction to a currently under-researched area within plant-pathogen interactions.

Sullivan S, Hart JE, Rasch P, Walker CH, Christie JM (2016) Phytochrome A Mediates Blue-Light Enhancement of Second-Positive Phototropism in Arabidopsis. Front Plant Sci. 7:290 http://dx.doi.org/10.3389/fpls.2016.00290 Open AccessFrontiersPHOT1

John Christie (Glasgow) is the corresponding author on this investigation into the role of the blue-light receptor phototropin 1 (phot1) during hypocotyl phototropism. Curvature of this organ is enhanced by treatment by red-light mediated by the phytochromeA receptor. However this study shows that pre-treatment with blue-light can also enhance this hypocotyl curvature although this did not occur at higher light intensities. In addition phototropic enhancement was also lacking when PHOT1 is expressed only in the hypocotyl epidermis. Therefore the study shows that the phyA impact on phot1 signaling is restricted to low light intensities and in tissues other than the epidermis.

Zhong Tang, Yanling Lv, Fei Chen, Wenwen Zhang, Barry P. Rosen, and Fang-Jie Zhao (2016) Arsenic Methylation in Arabidopsis thaliana Expressing an Algal Arsenite Methyltransferase Gene Increases Arsenic Phytotoxicity J. Agric. Food Chem. http://dx.doi.org/10.1021/acs.jafc.6b00462 Open Access ArsM

This synthetic biology-focused study is led by Fang-Jie Zhao at Rothamstead Research. The authors take an algal gene (arsM) that allows the transformation of inorganic arsenic to a more volatile methylated version. The biological activity of this enzyme was successfully transferred to two different Arabidopsis ecotypes. However interestingly these transgenic plants became more sensitive to arsenic in growth media suggesting that the new methylated arsenic intermediate is more phytotoxic than inorganic arsenic. Therefore this study demonstrates a negative consequence of this project that attempted to engineer arsenic tolerance in plants. Once again this demonstrates that nature rarely acts predictably and any great ideas usually need to be tested in vivo.

Ploch S, Rose L, Bass D, Bonkowski M (2016) High Diversity Revealed in Leaf Associated Protists (Rhizaria: Cercozoa) of Brassicaceae J Eukaryot Microbiol. http://dx.doi.org/10.1111/jeu.12314

After a fantastic opening line in the abstract, ‘The largest biological surface on earth is formed by plant leaves’, this study includes the work of David Bass from the Natural History Museum in London. They investigate the abundance of protists that associate with leaf-inhabiting microorganisms, the “phyllosphere microbiome“. Their findings demonstrate that protists should be considered an important part of the diversity of plant-interacting microbial organisms.

Hunter LJ, Brockington SF, Murphy AM, Pate AE, Gruden K, MacFarlane SA, Palukaitis P, Carr JP (2016) RNA-dependent RNA polymerase 1 in potato (Solanum tuberosum) and its relationship to other plant RNA-dependent RNA polymerases Sci Rep. 6:23082 http://dx.doi.org/10.1038/srep23082 Open Access

John Carr (Cambridge) is the UK-lead on this collaboration with Slovenian and Korean researchers. They primarily investigate the role of the RDR1 RNA-dependent RNA polymerase (RDRs) in potato. In Arabidopsis the RDR1 gene contributes to basal viral resistance but potato plants deficient in StRDR1 do not show altered susceptibility to three different plant viruses. In addition they perform a phylogenetic analysis on the RDR genes and identify a novel RDR7 gene that is only found in Rosids (but not Arabidopsis.

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