GARNet Research Roundup: August 10th 2018

Tags: No Tags
Comments: No Comments
Published on: August 10, 2018

There are three papers in this week’s GARNet research roundup. The first paper is led by Jill Harrison’s lab in Bristol and she also provides an audio description of this work that has characterised a role for CLAVATA genes in the transition from 2D to 3D plant growth. The second paper from Ian Graham’s lab in York introduces the role of the MOTHER-OF-FT-AND-TFL1 gene during seed germination whilst the final paper includes co-authors from SLCU and Nottingham and has identified the RALF34 protein as a novel ligand that influences cell wall growth.

Whitewoods CD, Cammarata J, Nemec Venza Z, Sang S, Crook AD, Aoyama T, Wang XY, Waller M, Kamisugi Y, Cuming AC, Szövényi P, Nimchuk ZL, Roeder AHK, Scanlon MJ, Harrison CJ (2018) CLAVATA Was a Genetic Novelty for the Morphological Innovation of 3D Growth in Land Plants. Curr Biol. doi: 10.1016/j.cub.2018.05.068

Open Access

Chris Whitewoods and Joe Cammarata are co-first authors in this UK-US-Japan collaboration that is led by GARNet committee member Jill Harrison from the University of Bristol. They have investigated the expression and function of CLAVATA genes during moss development with particular focus on the transition from 2D to 3D growth, showing that these genes are essential for gametophyte development. By showing the presence or absence of CLAVATA genes in different lower plant species they demonstrate that they are important for the transition between different modes of growth.

Jill talks about this work on the GARNet YouTube channel and podcast.

Vaistij FE, Barros-Galvão T, Cole AF, Gilday AD, He Z, Li Y, Harvey D, Larson TR, Graham IA (2018) MOTHER-OF-FT-AND-TFL1 represses seed germination under far-red light by modulating phytohormone responses in Arabidopsis thaliana. Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1806460115

Open Access

Fabian Vaistij is the first author on this paper from the lab of Ian Graham at the University of York that investigates the role of the MOTHER-OF-FT-AND-TFL1 (MFT) in the control of seed germination in Arabidopsis. They show that MFT is upregulated by far red light via the previously characterised PIF1/SOM/ABI5/DELLA pathway whilst repressed by red light through the action of the SPATULA (SPT) transcription factor. The activity of MFT alters levels of ABA and GA that ultimately delay germination in conditions with higher levels of FR light.

Gonneau M, Desprez T, Martin M, Doblas VG, Bacete L, Miart F, Sormani R, Hématy K, Renou J, Landrein B, Murphy E, Van De Cotte B, Vernhettes S, De Smet I, Höfte H (2018) Receptor Kinase THESEUS1 Is a Rapid Alkalinization Factor 34 Receptor in Arabidopsis. Curr Biol. doi: 10.1016/j.cub.2018.05.075
This French-led study that has Martine Gonneau and Thierry Desprez as co-lead authors includes Benoit Landrien (SLCU, Cambridge) and Evan Murphy (University of Nottingham) as co-authors. This research adds further detail to a signaling network that coordinates cell wall growth following different stimuli. They show that the rapid peptide alkalinization factor 34 (RALF34) is the ligand for the previously characterized THESEUS1 receptor kinase and that the activity of this signaling module is dependent on FERONIA, which is another RALF receptor.

GARNet Research Roundup: July 16th

This week’s GARNet research roundup begins with a set of papers looking at aspects of the plant defence response with a focus on the cell wall. Firstly work from Mike Deeks’ lab in Exeter assesses the role of FORMIN4 during pre-invasion cell wall apposition. Secondly Sara Pose and Paul Knox (Leeds) are involved with a study looking at how altered cell wall lignin composition alters the defense response. Finally Joe McKenna and Cyril Zipfel are co-authors on a Norwegian-led study that looks at the influence of plant cell wall integrity maintenance in immune signalling.

Relatedly is a study from the Devoto lab at RHUL looks at the role of the defence hormone methyl jasmonate in Arabidopsis cell culture.

Next are two papers that research different aspects of the plant ER. Verena Kriechbaumer (Oxford Brookes) looks at plant ER-localised Lunapark proteins whilst a study from the University of Warwick provides a preliminary structural analysis of the RTNLB13 reticulon protein.

The seventh and eight papers are involved with the plant response to different growth conditions. Research from University of Nottingham looks at the response of the cortical cell layer of the root meristem to low phosphate conditions whilst work from University of Southampton investigates the relationship between nitrate and copper signaling.

The next paper is from Emily Flashman’s lab at the University of Oxford and looks at the role of plant cysteine oxidases as oxygen sensors whilst the tenth paper features John Doonan (Aberystwyth University) as a co-author and investigates how a histone acetyltransferase affects trichome development.

Finally is a paper from Pierre Baudal and Kirsten Bomblies (John Innes Centre) that uses Arabidopsis arenosa as a model to investigate the emergence of novel flowering time alleles in populations that have colonised along railway corridors.

Sassmann S, Rodrigues C, Milne SW, Nenninger A, Allwood E, Littlejohn GR, Talbot NJ, Soeller C, Davies B, Hussey PJ, Deeks MJ (2018) An Immune-Responsive Cytoskeletal-Plasma Membrane Feedback Loop in Plants. Curr Biol. doi: 10.1016/j.cub.2018.05.014

Open Access

Stefan Sassmann is the lead author of this paper from Mike Deeks’s lab in Exeter. They investigate the role of the membrane-integrated FORMIN4 protein in the process of cell wall apposition, which occurs as part of the plant immune response and is dependent on actin dynamics. FORMIN4 is stably localised apart from the active traffic of the endomembrane system and removing its function compromises the defense response, presumably by altering actin distribution at sites of cell wall apposition. This work demonstrates that FORMIN4 acts as a key component of the pre-invasion defense response.

Gallego-Giraldo L, Posé S, Pattathil S, Peralta AG, Hahn MG, Ayre BG, Sunuwar J, Hernandez J, Patel M, Shah J, Rao X, Knox JP, Dixon RA (2018) Elicitors and defense gene induction in plants with altered lignin compositions. New Phytol. doi: 10.1111/nph.15258

Open Access

Sara Pose and Paul Knox (University of Leeds) are co-authors on this US-led study that investigates how lignin composition can influence the defence response. Plants with the same lignin content but changed lignin compositions show altered expression in genes involved with different arms of the defense response. This indicates that cell wall lignin composition plays a significant role in the plants ability to response to different sources of pathogen attack.

Engelsdorf T, Gigli-Bisceglia N, Veerabagu M, McKenna JF, Vaahtera L, Augstein F, Van der Does D, Zipfel C, Hamann T (2018) The plant cell wall integrity maintenance and immune signaling systems cooperate to control stress responses in Arabidopsis thaliana. Sci Signal. doi: 10.1126/scisignal.aao3070

Joe McKenna (Imperial College, now Oxford Brookes University) and Cyril Zipfel (The Sainsbury Laboratory, Norwich) are co-authors on this Norwegian-led study that looks at the plant cell wall integrity maintenance mechanism and how it responses to the challenges of growth, development and environmental stresses. They identified a set of receptor-like kinases that are key for the responses elicted by cell wall damage (CWD). Conversely they showed that the components of the pattern-triggered immunity (PTI) signaling pathway repress responses to CWD. This study provides insights into how cell wall responses interact with downstream gene expression changes following pathogen challenge.

Bömer M, O’Brien JA, Pérez-Salamó I, Krasauskas J, Finch P, Briones A, Daudi A, Souda P, Tsui TL, Whitelegge JP, Paul Bolwell G, Devoto A (2018) COI1-dependent jasmonate signalling affects growth, metabolite production and cell wall protein composition in Arabidopsis. Ann Bot. doi: 10.1093/aob/mcy109

Open Access

Moritz Bömer works with Alessandra Devoto at Royal Holloway University of London and leads this research that looks at the effect of MeJA treatment on growth and gene expression in Arabidopsis cell culture. They demonstrate that both MeJA treatment or COI1 overexpression causes changes in the abundance of proteins involved in cell wall loosening as well as altered levels of primary metabolites alanine, serine and succinic acid. This work demonstrates a close link between hormone signaling, the defence response and the metabolic profile of Arabidopsis cells.

Dr Devoto and her academic colleagues at RHUL are profiled in the latest GARNish newsletter available for download from the GARNet website.

Kriechbaumer V, Breeze E, Pain C, Tolmie F, Frigerio L, Hawes C (2018) Arabidopsis Lunapark proteins are involved in ER cisternae formation. New Phytol. doi: 10.1111/nph.15228

Open Access

Verena Kriechbaumer from Oxford Brookes University leads this research that investigates the in planta function of novel ER network-shaping proteins called Lunaparks (LNP). They show that these proteins localise to the entire ER network in Arabidopsis. They use confocal microscopy to show that altering the level of LNP gene expression changes ER morphology, possibly by regulating the formation of ER cisternae.

Chow M, Sklepari M, Frigerio L, Dixon AM (2018) Bacterial expression, purification and biophysical characterization of the smallest plant reticulon isoform, RTNLB13 Protein Expr Purif. doi: 10.1016/j.pep.2018.06.015

Open Access

Michael Chow worked with Lorenzo Frigerio and Ann Dixon at the University of Warwick to provide a preliminary structure and topology analysis of the plant RTNLB13 reticulon protein. This ER-associated integral membrane protein was expressed in bacteria and then a variety of analysis techniques were used to suggest that RTNLB13 has a high level of self-association and protein-membrane interactions.

Janes G, von Wangenheim D, Cowling S, Kerr I, Band L, French AP, Bishopp A (2018) Cellular Patterning of Arabidopsis Roots Under Low Phosphate Conditions Front Plant Sci. doi: 10.3389/fpls.2018.00735

Open Access

George Janes works with Anthony Bishopp at the University of Nottingham and leads this study that looks at root meristem development under low phosphate conditions. They show that in phosphate-limiting conditions the cortex layer of the root meristem contains almost double the number of cells, which results in a greater number of root hair-forming epidermal cells. As this change can occur within 24hrs the rapidity of the response represents a significant adaptation to a changing root environment.

Hippler FWR, Mattos-Jr D, Boaretto RM, Williams LE (2018) Copper excess reduces nitrate uptake by Arabidopsis roots with specific effects on gene expression J Plant Physiol. doi: 10.1016/j.jplph.2018.06.005

Open Access

Franz Hippler (University of Southampton) leads this UK-Brazil collaboration showing that growth of Arabidopsis plants in excess copper conditions causes a downregulation in nitrate uptake. This is due to both direct and indirect changes on the gene expression of nitrate transporters as well as a reduction in transcript level of the plasma membrane proton pump, AHA2. This effect was altered when copper levels were reduced demonstrating that copper toxicity acts at the level of nitrate transport and homeostasis.

White MD, Kamps JJAG, East S, Taylor Kearney LJ, Flashman E (2018) The Plant Cysteine Oxidases from Arabidopsis thaliana are kinetically tailored to act as oxygen sensors J Biol Chem.

doi: 10.1074/jbc.RA118.003496

Open Access

Mark White is the lead author on this work from the lab of Emily Flashman at the University of Oxford in which they look at the role of plant cysteine oxidases (PCOs) as oxygen sensors. They assessed the kinetics of each of AtPCO1 to AtPCO5 proteins and show that the most catalytically competent isoform is AtPCO4, in terms of both responding to O2, and oxidizing hypoxic responsive proteins. This work validates an O2-sensing role for the PCOs and provides evidence for functional differences between members of this enzyme family.

Kotak J, Saisana M, Gegas V, Pechlivani N, Kaldis A, Papoutsoglou P, Makris A, Burns J, Kendig AL, Sheikh M, Kuschner CE, Whitney G, Caiola H, Doonan JH, Vlachonasios KE, McCain ER, Hark AT (2018) The histone acetyltransferase GCN5 and the transcriptional coactivator ADA2b affect leaf development and trichome morphogenesis in Arabidopsis. Planta. doi: 10.1007/s00425-018-2923-9 Open Access

John Doonan (Aberystwyth University) is a co-author on this manuscript led by Jenna Kotak and Amy Herd in the USA. They investigate plants that have mutations in the histone acetyltransferase GCN5 and associated transcriptional coactivator ADA2b. These genes have been previously demonstrated as being involved in endoreduplication and trichome branching. They show that these mutants have alterations in the number and patterning of trichome-branches and that ADA2b and GCN5 are required to couple nuclear content with cell growth and morphogenesis.

Baduel P, Hunter B, Yeola S, Bomblies K. Genetic basis and evolution of rapid cycling in railway populations of tetraploid Arabidopsis arenosa (2018) PLoS Genet.

doi: 10.1371/journal.pgen.1007510 Open Access

Pierre Baduel and Kirsten Bomblies (John Innes Centre) lead this work that was conducted prior to Kirsten’s move to Norwich. In this study they follow the colonization of populations of Arabidopsis arenosa along mountain railway corridors. They demonstrate that selective pressure has occurred on novel alleles of flowering time genes and discuss the implications for ruderal communities linked to railways as allele conduits linked to local adaptations.

GARNet Research Roundup: April 27th

This weeks GARNet research roundup features four papers that include Malcolm Bennett (University of Nottingham) as an author. The first three are linked manuscripts that investigate the role of auxin on root hair development that is controlled by varying phosphate levels. Ranjan Swarup provides an audio summary of two of these papers on the GARNet YouTube and podcast feeds.

The fourth paper from Nottingham is a collaboration with GARNet PI Jim Murray (Cardiff University) that characterises the STM gene network and its influence on meristem development.

The fifth paper from the lab of Paul Dupree in Cambridge characterises the stem transcriptome whilst the next paper from Iain Johnston and George Bassel (University of Birmingham) identifies a bet-hedging network that influences seed germination. The final paper features Seth Davies (University of York) as a co-author and investigates the impact of changes in circadian rhythms on short architecture.

Researchers at the University of Nottingham are involved in three back-to-back papers that add a mechanistic framework to the relationship between phosphate and auxin signaling in root hairs.

Bhosale R, Giri J, Pandey BK, Giehl RFH, Hartmann A, Traini R, Truskina J, Leftley N, Hanlon M, Swarup K, Rashed A, Voß U, Alonso J, Stepanova A, Yun J, Ljung K, Brown KM, Lynch JP, Dolan L, Vernoux T, Bishopp A, Wells D, von Wirén N, Bennett MJ, Swarup R (2018) A mechanistic framework for auxin dependent Arabidopsis root hair elongation to low external phosphate. Nat Commun. 9(1):1409. doi: 10.1038/s41467-018-03851-3

Open Access

The first paper is led by Ranjan Swarup and defines components of auxin biosynthetic, transport and signaling pathways that are involved in the change root hair development in response to different phosphate concentrations in Arabidopsis. Ranjan discusses this paper on YouTube.

Giri J, Bhosale R, Huang G, Pandey BK, Parker H, Zappala S, Yang J, Dievart A, Bureau C, Ljung K, Price A, Rose T, Larrieu A, Mairhofer S, Sturrock CJ, White P, Dupuy L, Hawkesford M, Perin C, Liang W, Peret B, Hodgman CT, Lynch J, Wissuwa M, Zhang D, Pridmore T, Mooney SJ, Guiderdoni E, Swarup R, Bennett MJ (2018). Rice auxin influx carrier OsAUX1 facilitates root hair elongation in response to low external phosphate. Nat Commun. 9(1):1408. doi: 10.1038/s41467-018-03850-4

Open Access

This paper led by Malcolm Bennett uses a rice model to investigate the relationship between auxin and root hair elongation in response to low concentrations of phosphate. They show rice aux1 mutants have significant changes in root architecture.

Dindas J, Scherzer S, Roelfsema MRG, von Meyer K, Müller HM, Al-Rasheid KAS, Palme K, Dietrich P, Becker D, Bennett MJ, Hedrich R (2018) AUX1-mediated root hair auxin influx governs SCF(TIR1/AFB)-type Ca(2+) signaling. Nat Commun. 9(1):1174. doi: 10.1038/s41467-018-03582-5

Open Access

The third paper includes Malcolm Bennett as a co-author and investigates how the auxin transport and signaling pathways stimulate calcium signaling during root hair elongation.

Scofield S, Murison A, Jones A, Fozard J, Aida M, Band LR, Bennett M, Murray JAH (2018) Coordination of meristem and boundary functions by transcription factors in the SHOOT MERISTEMLESS regulatory network. Development pii: dev.157081. doi: 10.1242/dev.157081

Open Access
GARNet PI Jim Murray is the corresponding author on this manuscript that is led by Dr Simon Scofield and includes collaborators from the University of Nottingham. They have explored the gene regulatory network that is regulated by the key meristem identity gene SHOOT MERISTEMLESS (STM). This network includes an over-representation of transcription factor families, each of which have distinct roles in meristem development. They use in planta experimentation and in silico modeling to investigate the relationship between STM and CUC1 in more detail. Overall this study confirms that STM is a central regulator of shoot meristem function.

Faria-Blanc N, Mortimer JC, Dupree P (2018) A Transcriptomic Analysis of Xylan Mutants Does Not Support the Existence of a Secondary Cell Wall Integrity System in Arabidopsis. Front Plant Sci. 9:384. doi: 10.3389/fpls.2018.00384

Open Access

Paul Dupree (University of Cambridge) is the corresponding author of this study that uses a range of Arabidopsis cell wall mutants to investigate the stem transcriptome. In plants with defects in xylan synthesis the authors found surprisingly few transcriptional changes. This indicates that once plants have committed to a terminal secondary cell wall program there is little need for transcriptional changes even after cell wall damage.

Johnston IG, Bassel GW (2018) Identification of a bet-hedging network motif generating noise in hormone concentrations and germination propensity in Arabidopsis. J R Soc Interface. 15(141). pii: 20180042. doi: 10.1098/rsif.2018.0042.

Open Access
Iain Johnston (University of Birmingham) leads this study that has identified a bet-hedging network that links hormone signaling during Arabidopsis germination. This type of network allows plants to more easily adapt to varying environmental conditions but can preclude maximum growth. In this system the network is based upon the regulation of ABA synthesis, activity and degradation, which is maintained at a constant mean level even though it exhibits significant noise. They investigate the parameters that might be tweaked to reduce variation in germination rate and therefore might be targets for modification in order to maximise responses under particular environmental conditions.

George Bassel who is a co-author on this paper will be speaking at the GARNet2018 Meeting in York in September.

Rubin MJ, Brock MT, Baker RL, Wilcox S, Anderson K, Davis SJ, Weinig C (2018) Circadian rhythms are associated with shoot architecture in natural settings. New Phytol. doi: 10.1111/nph.15162.

Seth Davies (University of York) is a co-author on this study that assesses the effect of circadian rhythms on aerial phenotypes that lead to fruit production in field grown Arabidopsis. This was assessed over two growing seasons and they show that variation in clock function significantly impacts shoot architecture.

GARNet Research Roundup: March 29th

Tags: No Tags
Comments: No Comments
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

Tags: No Tags
Comments: No Comments
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

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

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.

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 12th

This weeks Arabidopsis Research Roundup begins with a study from SLCU that investigates the interaction between nitrate and cytokinin signaling in the shoot meristem. Next is research from Sheffield that studies changes to the macromolecular composition of the photosynthetic apparatus following the transition from dark to light. Third are three papers that include University of Edinburgh faculty members as co-authors; Gary Loake is involved in a global study on NO signaling, Karen Halliday is included on a study into the relationship between clock components and the PIF-mediated hypocotyl elongation and Naomi Nakayama contributes to the development of a model that explains PIN protein localisation. Cyril Zipfel (TSL) is a co-author on the fifth paper, which introduces a new signaling component in the defence response and whilst the penultimate paper includes Denis Murphy (University of South Wales) and investigates the effect of dioxins on seed development. The final paper documents research from Manchester and Nottingham that uses a cress endosperm as a model to test the elastic properties of thin biological membranes.

Landrein B, Formosa-Jordan P, Malivert A,, Schuster C, Melnyk CW,, Yang W, Turnbull C, Meyerowitz EM, Locke JCW,, Jönsson H (2018) Nitrate modulates stem cell dynamics in Arabidopsis shoot meristems through cytokinins. PNAS doi: 10.1073/pnas.1718670115.

Open Access

Henrik Jonsson and James Locke (SLCU) are corresponding authors on this investigation into the relationship between nitrate and cytokinin signalling in the Arabidopsis shoot meristem (SAM). They show that nitrate availability determines the size of the SAM, which is controlled by the transport of cytokinin precursors from the root to the shoot. A discussion about this paper with lead author Benoit Landrien and Professor Jonsson is available on the GARNet YouTube and iTunes channels.

Wood WHJ, MacGregor-Chatwin C, Barnett SFH, Mayneord GE, Huang X, Hobbs JK, Hunter CN, Johnson MP (2018) Dynamic thylakoid stacking regulates the balance between linear and cyclic photosynthetic electron transfer. Nature Plants. doi: 10.1038/s41477-017-0092-7

Open with this link

This research in this manuscript has come from the University of Sheffield with Matthew Johnson as the corresponding author. They have used atomic force microscopy (AFM) to investigate how the transition from dark to light affects the macromolecular architecture of the photosynthetic apparatus within the thylakoid membrane. This transition does not alter the antenna size of either photosystem yet increases the number of thylakoid grana. Overall these changes serve to regulate the balance between light harvesting, CO2 fixation and enabling the protection of PSII activity from the destructive effects of non-photochemical quenching.

Imran QM, Hussain A, Lee SU, Mun BG, Falak N, Loake GJ, Yun BW (2018) Transcriptome profile of NO-induced Arabidopsis transcription factor genes suggests their putative regulatory role in multiple biological processes. Sci Rep. doi: 10.1038/s41598-017-18850-5.

Open Access

Gary Loake (University of Edinburgh) is a contributor to this Korean-led manuscript that has performed expression analysis on plants treated with S-nitrosocysteine (CySNO). They have identified many novel NO-responsive transcription factors and were able to confirm the role of three random TFs in this response following analysis of loss of function mutants. This paper provides new insights into the molecular components that contribute to NO signalling during plant defence and immunity.

Martín G, Rovira A, Veciana N, Soy J, Toledo-Ortiz G, Gommers CMM, Boix M, Henriques R, Minguet EG, Alabadí D, Halliday KJ, Leivar P, Monte E Circadian Waves of Transcriptional Repression Shape PIF-Regulated Photoperiod-Responsive Growth in Arabidopsis. Curr Biol. doi: 10.1016/j.cub.2017.12.021

Karen Halliday (University of Ediburgh) is a co-author on this Spanish-led study that investigates how the expression of PHYTOCHROME-INTERACTING FACTORS (PIFs) genes is controlled. The activity of PIFs are responsible for determining the rate of hypocotyl elongation in different light conditions and this paper demonstrates that PSEUDO-RESPONSE REGULATORS PRR9/7/5 proteins act antagonistically to the PIFs by interacting at the promotor of the CDF5 transcription factor. This provides a mechanism to explain the circadian-controlled regulation of hypocotyl cell elongation.

Hernandez V, Barrio RA, Benítez M, Nakayama N, Romero-Arias JR, Villarreal Lujan C (2018) A physico-genetic module for the polarisation of auxin efflux carriers PIN-FORMED (PIN). Phys Biol. doi: 10.1088/1478-3975/aaac99

Naomi Nakayama (University of Edinburgh) is a co-author on this Mexican-led study that proposes a physico-genetic model that explains the localization of PIN auxin transporter proteins to the Arabidopsis plasma membrane. This model confirms experimental observations and allows the prediction that mechanical forces can predominate over molecular components.

Wang J, Grubb LE, Wang J, Liang X, Li L, Gao C, Ma M, Feng F, Li M, Li L, Zhang X, Yu F, Xie Q, Chen S, Zipfel C, Monaghan J, Zhou JM (2018) A Regulatory Module Controlling Homeostasis of a Plant Immune Kinase. Mol Cell. doi: 10.1016/j.molcel.2017.12.026

This Chinese-led paper includes Cyril Zipfel (TSL) as a co-author and identifies the U-box proteins PUB25 and PUB26 as E3 ligases for the cytoplasmic kinase BIK1, which is a key rate limiting component of the plant defence response. This multi-protein regulatory module provides another level of complexity to our understanding of the molecular factors involved in plant immunity.

Hanano A, Almousally I, Shaban M, Murphy DJ (2018) Exposure of Arabidopsis Plants to Dioxin Results in a Wrinkled Seed Phenotype that is likely due to 20S Proteasomal Degradation of WRI1. J Exp Bot. doi: 10.1093/jxb/ery027

Denis Murphy (University of South Wales) is a co-author on this Syrian-led study that uses Arabidopsis seeds to test the negative effects of dioxins. Seeds treated with dioxins have a wrinked phenotype that corresponds to changes in the expression of genes related to lipid and carbohydrate metabolism. Overall this study reveals a novel set of genetic changes effects caused by dioxins that explain the profound effects on seed development.

S. P. Pearce, J. R. King, T. Steinbrecher, G. Leubner-Metzger, N. M. Everitt, M. J. Holdsworth (2018) Finite indentation of highly curved elastic shells Proceedings of the Royal Society A doi: 10.1098/rspa.2017.0482

Open Access

Plant scientist Mike Holdsworth (University of Nottingham) is a co-author on this paper that has used the endosperm from garden cress (Lepidium sativum) as the experimental model to define the elastic properties of a thin biological surface. Indentation experiments have been classically used to measure these properties and then develop mathematically models that explain their characteristics. These models rely on an assumed flat surface whereas in reality any surface will often be curved. By obtaining measurements from identations studies on the cress endosperm they are able to better refine the models that explain the properties of the membrane in this context.

Arabidopsis Research Roundup: January 10th 2018

This Arabidopsis Research Roundup covers the final papers of 2017 and the first of this new year. The initial paper is led by researchers in Bristol and characterises how the multifaceted BIG protein influences stomatal dynamics in response to altered CO2. Second is a manuscript from SLCU that for the first time in plants demonstrates nuclear sequestration of cell cycle regulated mRNAs.

Next is a paper from Rothamsted that describes a role for the hormone GA during floral development. David Salt (Nottingham) is then a co-author on a manuscript that has determined a role for the CTL protein in ion homeostasis.

Seth Davies from York is the lead author on the next study that investigates a link between metabolism and the circadian clock. The sixth paper looks at genes involved in the control of autophagy and features Patrick Gallois (Manchester) as a co-author.

There are three papers from researchers working on Norwich Research Park with Cyril Zipfel (TSL) involved in a study that looks at vacuolar trafficking of BR signaling components. Janneke Balk leads a study that characterises enzymes involved in biosynthesis of metal co-factors whilst the final NRP-based paper from Nick Pullen and Steven Penfield (John Innes Centre) describes the Leaf-GP open software for automated plant phenotyping.

The penultimate paper uses a set of PlantProbes (developed by Paul Knox at Leeds) to study pollen development whilst the final paper from Keith Lindsey (Durham) describes the application of a Bayesian statistical methodology to model the parameters that control a hormone signaling network.

He J, Zhang RX, Peng K, Tagliavia C, Li S, Xue S, Liu A, Hu H,, Zhang J, Hubbard KE,, Held K, McAinsh MR, Gray JE, Kudla J, Schroeder JI, Liang YK, Hetherington AM (2018) The BIG protein distinguishes the process of CO2 -induced stomatal closure from the inhibition of stomatal opening by CO2. New Phytol. doi: 10.1111/nph.14957 Open Access

Alistair Hetherington (University of Bristol) leads this UK-USA-China collaboration that has characterised a role for the mysterious BIG protein during stomatal closure in response to altered CO2 concentration. Interestingly BIG mutants do not show a defect in stomatal opening in response to altered CO2, allowing the dissection of this complex response through the activity of this protein. It remains to be determined exactly how the BIG protein influences this process.

Yang W, Wightman R, Meyerowitz EM (2017) Cell Cycle Control by Nuclear Sequestration of CDC20 and CDH1 mRNA in Plant Stem Cells. Mol Cell. doi: 10.1016/j.molcel.2017.11.008

Elliott Meyerowitz (SLCU) is the corresponding author of this research that provides the first characterisation in plants of nuclear sequestration of mRNAs from developmental important genes. The authors show that Arabidopsis anaphase-promoting complex/cyclosome (APC/C) coactivator genes CDC20 and CCS52B are confined to the nucleus in prophase, preventing translation of the cognate proteins until metaphase, which appears to protect cyclins from degradation at an inappropriate phase of the cell cycle

Plackett ARG, Powers SJ, Phillips AL, Wilson ZA, Hedden P, Thomas SG4 (2017) The early inflorescence of Arabidopsis thaliana demonstrates positional effects in floral organ growth and meristem patterning. Plant Reprod. doi: 10.1007/s00497-017-0320-3

This study is led from Rothamsted Research and includes Zoe Wilson from the University of Nottingham. They perform a systematic analysis of early floral organ initiation across the Arabidopsis inflorescence, discovering that both GA-dependent and independent stages are important for this process, albeit via the activity of presently unknown factors.

Gao YQ, Chen JG, Chen ZR An D, Lv QY, Han ML, Wang YL, Salt DE, Chao DY (2017) A new vesicle trafficking regulator CTL1 plays a crucial role in ion homeostasis. PLoS Biol. doi: 10.1371/journal.pbio.2002978

Open Access

David Salt (University of Nottingham) is a co-author on this Chinese-led investigation into the role of the vesicle trafficking regulator choline transporter (CTL) during the control of ionome homeostasis. Using ctl1 mutants they show that this function is required for the action of certain ion transporters as well as during plasmodesmata (PD) development. This study provides novel insights into the role of vesicular transport in the control of ion homeostasis and how the location of these ions might alter vesicle activity.

Sánchez-Villarreal A, Davis AM, Davis SJ (2017) AKIN10 Activity as a Cellular Link Between Metabolism and Circadian-Clock Entrainment in Arabidopsis thaliana.

Plant Signal Behav. doi: 10.1080/15592324.2017.1411448

Seth Davies (University of York) is the corresponding author on this study demonstrating that overexpression of the AKIN10 subunit of the SnRK1 complex results in increased period length of the circadian clock. The authors postulate about the possible links between metabolic rate and function of the clock, allowing them to present a model of action that features each of the central regulatory elements.

Havé M, Balliau T, Cottyn-Boitte B, Dérond E, Cueff G, Soulay F, Lornac A, Reichman P, Dissmeyer N, Avice JC, Gallois P, Rajjou L, Zivy M, Masclaux-Daubresse C (2017) Increase of proteasome and papain-like cysteine protease activities in autophagy mutants: backup compensatory effect or pro cell-death effect? J Exp Bot. doi: 10.1093/jxb/erx482

Open Access
This study is led by French researchers and includes Patrick Gallois (University of Manchester) as a co-author. The work focuses on the role of the ATG genes during autophagy, the key process that controls nutrient recycling during senescence. In atg5 mutants they show that different sets of proteases are misregulated, suggestive of a complex relationship between the enzymes involved in nutrient remobilization.

Liu Q, Vain T, Viotti C, Doyle SM, Tarkowská D, Novák O, Zipfel C, Sitbon F, Robert S, Hofius D (2017) Vacuole Integrity Maintained by DUF300 Proteins Is Required for Brassinosteroid Signaling Regulation. Mol Plant. doi: 10.1016/j.molp.2017.12.015

Cyril Zipfel (TSL) is a member of this Pan-European consortium that investigates the role of the vacuolar proteins, LAZARUS1 (LAZ1) and LAZ1 HOMOLOG1 (LAZ1H1) on the cellular cycling of BR-signaling components. Plants with mutations in laz1 and laz1h1 show increased BAK1 accumulation at the tonoplast as well as enhanced BRI1 trafficking and degradation. These DUF300 proteins appear to play a specific role in BR signalling as other vacuolar-associated proteins are not involved in this process.

Kruse I, Maclean A, Hill L, Balk J (2017) Genetic dissection of cyclic pyranopterin monophosphate biosynthesis in plant mitochondria. Biochem J. doi: 10.1042/BCJ20170559 Open Access

Janneke Balk (John Innes Centre) leads this study that has identified novel alleles in mitochondrial enzymes that are involved in the biosynthesis of metal cofactors. Analysis of these enzyme mutant reveals that they show deficiencies in the synthesis of cyclic pyranopterin monophosphate (cPMP), revealing fresh insights into the metabolic processes involving this key intermediate.

Zhou J, Applegate C, Alonso AD, Reynolds D, Orford S, Mackiewicz M, Griffiths S, Penfield S, Pullen N (2017) Leaf-GP: an open and automated software application for measuring growth phenotypes for arabidopsis and wheat. Plant Methods. doi: 10.1186/s13007-017-0266-3

Open Access

Nick Pullen and Steve Penfield (John Innes Centre) introduce this new software tool for the automated measurement of plant phenotypes. This Leaf-GP software is open access and has the sophistication to discriminate between different aspects of both Arabidopsis and greenhouse growth wheat.

This paper is back of a special issue of Plant Methods that is based on the use of Computer Vision in Plant Phenotyping.

Ndinyanka Fabrice T, Vogler H, Draeger C, Munglani G, Gupta S, Herger AG, Knox JP, Grossniklaus U, Ringli C (2017) LRX Proteins play a crucial role in pollen grain and pollen tube cell wall development. Plant Physiol. doi: 10.1104/pp.17.01374

Open Access

This Swiss-led study looks into the role of LRX proteins during cell wall formation and how they affect pollen germination and pollen tube formation. The authors took advantage of the molecular tools produced by Paul Knox (University of Leeds) as part of his Plant Probes project.

Vernon I, Liu J, Goldstein M, Rowe J, Topping J, Lindsey K (2017) Bayesian uncertainty analysis for complex systems biology models: emulation, global parameter searches and evaluation of gene functions. BMC Syst Biol. doi: 10.1186/s12918-017-0484-3 Open Access

Keith Lindsey (University of Durham) leads this paper that applies a Bayesian statistical methodology to analyse a model of hormonal crosstalk in the Arabidopsis root. They show that this technique can provide new insight into the behavior of models and enables the identification of new interesting rate parameters.

Arabidopsis Research Roundup: December 18th

This festive Arabidopsis Research Roundup begins with a commentary article from a global consortium of plant scientists who propose a framework of future training for researchers who will take advantage of the experimental tools available in Arabidopsis. Secondly is study from Caroline Dean (JIC) that defines the role of the LHP1 protein in epigenetic control of gene expression. Thirdly John Doonan (Aberystwyth) is a co-author of work that defines an important component of mitotic spindle formation. Next is a study led by Zinnia Gonzalez-Carranza in Nottingham that offers further insights into the function of the HWS gene. The fifth study comes from the lab of Alexander Ruban (QMUL), further investigating the importance of NPQ in photosynthetic control. The sixth paper from the Van Ooijen lab (Edinburgh) characterises the role of sumoylation in the control of CCA1 activity. The penultimate paper from the Harberd lab in Oxford defines the importance of DNA mismatch repair on genome sequence integrity whilst the final paper characterises the next phase in the long story of Arabidopsis ALF4 function and includes Charles Melynk (SLCU) as a co-author.

Friesner J et al (2017) The Next Generation of Training for Arabidopsis Researchers: Bioinformatics and Quantitative Biology. Plant Physiol. doi: 10.1104/pp.17.01490. Open Access

The current GARNet PI Jim Murray and past GARNet coordinator Ruth Bastow are authors in this international consortium that suggests future directions for the global Arabidopsis community. This consortium is led by Joanna Friesner and concludes that it is critical that the next generation of plant scientists receive appropriate training in bioinformatics and quantitative biology so as to take advantage of the remarkable array of datasets that are now available to Arabidopsis researchers.

Berry S, Rosa S, Howard M, Bühler M, Dean C (2017) Disruption of an RNA-binding hinge region abolishes LHP1-mediated epigenetic repression Genes Dev. doi: 10.1101/gad.305227.117 Open Access

Caroline Dean (John Innes Centre) leads this study that investigates the role of the polycomb associated protein LIKE HETEROCHROMATIN PROTEIN 1 (LHP1) in the regulation of the repressive histone mark H3K27me3. They demonstrate that the intrinsically disordered hinge region of LHP1 is responsible for RNA-binding and that disruption of this region prevents the formation of sub-nuclei foci, provides a potential link to wider epigenetic regulation.

Lee YJ, Hiwatashi Y, Hotta T, Xie T, Doonan JH, Liu B (2017) The Mitotic Function of Augmin Is Dependent on Its Microtubule-Associated Protein Subunit EDE1 in Arabidopsis thaliana. Current Biol. doi: 10.1016/j.cub.2017.11.030

Open Access

John Doonan and colleagues at Aberystwyth University are co-authors on this study regarding the role of the Microtubule-Associated Protein Subunit EDE1, which is a member of the Augmin complex, during mitosis. EDE1 specifically localised with the augmin complex during spindle formation, a role that cannot be replaced by the homologous protein AUG8. This work reveals that specificity of the augmin complex can be determined by interaction with subunits that only contribute to complex function during particular phases of the cell cycle.

Zhang X, Jayaweera D, Peters JL, Szecsi J, Bendahmane M, Roberts JA, González-Carranza ZH (2017) The Arabidopsis thaliana F-box gene HAWAIIAN SKIRT is a new player in the microRNA pathway. PLoS One. doi: 10.1371/journal.pone.0189788 Open Access

Zinnia Gonzalez-Carranza (Nottingham) is the corresponding author on this study that follows on from work published earlier in 2017 regarding the role of the HAWAIIAN SKIRT gene is plant development. In this latest work they identify mutations in the previously characterized Exportin-5 HASTY gene as suppressors of the hws mutant phenotype. Further investigation shows that HWS genetically interacts with other genes involved in miRNA pathway indicates that HWS somehow interacts with biogenesis, accumulation or function of these small RNAs.

Townsend AJ1, Ware MA1, Ruban AV (2017) Dynamic interplay between photodamage and photoprotection in photosystem II. Plant Cell Environ doi: 10.1111/pce.13107

In this paper Alexander Ruban (QMUL) is the corresponding author on work that expands his groups contribution to the understanding of the role non-photochemical quenching (NPQ) plays during photoinhibition. In this work they compare the activity of NPQ versus endogenous photosystemI repair mechanisms in the maintenance of photosynthetic activity during photoinhibitory conditions. Overall they conclude that NPQ is a more important mechanism for photoprotection under short periods of illumination.

Hansen LL, Imrie L, Le Bihan T, van den Burg HA, van Ooijen G (2017) Sumoylation of the Plant Clock Transcription Factor CCA1 Suppresses DNA Binding. J Biol Rhythms doi: 10.1177/0748730417737695 Open Access

This paper from the Van Ooijen lab accompanies one that was featured in last weeks ARR and extends their finding that sumoylation plays an important role in control of the circadian clock. In this paper they show that the CCA1 clock protein is sumoylated and that perturbing this modification alters the binding of CCA1 to a target promotor, even though it’s localization or stability were unaffected. Using an in vitro system they show that sumoylation is a direct determinant of CCA1 binding to its target promotor suggesting that this PTM fine tunes the activity of this key circadian control element.

Belfield EJ, Ding ZJ, Jamieson FJC, Visscher AM, Zheng SJ, Mithani A, Harberd NP (2017) DNA mismatch repair preferentially protects genes from mutation. Genome Res. doi: 10.1101/gr.219303.116

Past GARNet Advisory board member Nick Harberd (Oxford) leads this multi-generational study on the effect of DNA mismatch repair (MMR) on maintenance of an entire genome. They perform whole genome sequencing across five generations of Arabidopsis plants with a mutation in the MMR pathway and show that particular types of nucleotide error are more prevelant amongst the total 9000 mutations that accumulate. Interestingly they show that single nucleotide variants are more likely to accumulate in genic regions, indicating that protein coding areas of the genome are preferentially protected from damage.

Bagchi R, Melnyk CW, Christ G, Winkler M,, Kirchsteiner K, Salehin M, Mergner J, Niemeyer M, Schwechheimer C, Calderón Villalobos LIA, Estelle M (2017) The Arabidopsis ALF4 protein is a regulator of SCF E3 ligases. EMBO J. doi: 10.15252/embj.201797159

During his time as a research fellow at the Sainsbury lab in Cambridge. Charles Melynk contributed to this research that is a throwback to the early day of Arabidopsis mutant analysis. The alf4 was first described as a possible auxin mutant in 1995 and this work brings this study full circle by characterising the ALF4 protein as a novel regulator of SCF complexes, which are known to be involved in auxin and GA signaling. ALF4 specifically functions by interacting with the SCF-core component RBX1. Future work will determine whether this effect is specific to SCFs involved in hormone signaling or whether it is a more general effect.

«page 1 of 2

Follow Me
August 2018
« Jul    

Welcome , today is Wednesday, August 22, 2018