This edition of the GARNet research roundup begins with a study from the University Leicester that investigates the rate of selection of genes expressed in Arabidopsis pollen.
The second and third papers focus on the function of members of the AP2 family of transcription factors. Sarah McKim’s lab in Dundee characterizes the role of APETALA2 during barley stem elongation whilst the other paper investigates the function of the Arabidopsis PUCHI gene and includes co-authors from the University of Nottingham.
The fourth paper is from Lars Ostergaard’s lab at the John Innes Centre and demonstrates the benefit of using models to understand developmental processes in crop plants. The next paper from the University of Glasgow investigates the plant response to low fluence rates of UV-B light.
The penultimate paper features authors from Oxford Brookes University and characterizes a novel LINC-KASH protein in maize whilst the final paper is from the University of Cambridge and investigates the novel function of two members of DUF579 family in methylation of glucuronic acid residues.
Harrison MC, Mallon EB, Twell D, Hammond RL (2019) Deleterious mutation accumulation in Arabidopsis thaliana pollen genes: a role for a recent relaxation of selection. Genome Biol Evol. doi: 10.1093/gbe/evz127
Open Access
This research from Hammond and Twell lab’s at the University of Leicester uses Arabidopsis to investigate the hypothesis that pollen genes evolve faster than sporophytic genes. This study is challenging to perform in Arabidopsis as for the past million years the plant has been self-compatible, which causes reduction in pollen competition, increased homozygosity and a dilution of masking in diploid expressed, sporophytic genes. This study has two main findings: firstly prior to becoming self-compatible pollen genes evolved faster than sporophytic genes. Secondly, since becoming self-compatible selection has relaxed causing higher polymorphism levels and a higher build-up of deleterious mutations.
Patil V, McDermott HI, McAllister T, Cummins M, Silva JC, Mollison E, Meikle R, Morris J, Hedley PE, Waugh R, Dockter C, Hansson M, McKim SM (2019) APETALA2 control of barley internode elongation. Development. doi: 10.1242/dev.170373
Open Access
Vrushali Patil leads his study from the lab of current GARNet committee member Sarah McKim at the James Hutton Institute in Dundee. They show that the APETALA2 (AP2) transcription factor is necessary for stem elongation in Barley. In addition they demonstrate that AP2 expression is controlled by the activity of the microRNA mi172 as well as jasmonate signaling.
Trinh
DC, Lavenus J, Goh T, Boutté Y, Drogue Q, Vaissayre V, Tellier F, Lucas
M, Voß U, Gantet P, Faure JD, Dussert S, Fukaki H, Bennett MJ, Laplaze
L, Guyomarc’h S (2019) PUCHI regulates very long chain fatty acid biosynthesis during lateral root and callus formation. Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1906300116
Julien Lavenus, Ute Voß and Malcolm Bennett from University of Nottingham are co-authors on this French-led study that investigates the mechanism by which the AP2 family transcription factor PUCHI controls lateral root development. By performing a transcriptional analysis of developing lateral root cells they show that genes involved in very long chain fatty acid (VLCFA) biosynthesis enzymes are induced in a PUCHI dependent manner. Concomitantly they show puchi-1 mutant roots have reduced VLCFA content when compared with wildtype roots. They conclude that PUCHI regulates VLCFA biosynthesis as part of a pathway controlling cell proliferation during lateral root formation.
Stephenson P, Stacey N, Brüser M, Pullen N, Ilyas M, O’Neill C, Wells R, Østergaard L (2019) The power of model-to-crop translation illustrated by reducing seed loss from pod shatter in oilseed rape. Plant Reprod. doi: 10.1007/s00497-019-00374-9
Open Access
Pauline Stephenson and Lars Østergaard at the John Innes Centre lead this study in which they demonstrate that lessons learnt from understanding the genes involved in fruit ripening in Arabidopsis lead to an ability to adjust the pod-opening process in oilseed rape. They have combined two mutant alleles, first characterized in Arabidopsis, to develop OSR plants that have significantly increased yield. In addition they present a new software tool for the analysis of pod shatter data in other crops plants.
O’Hara A, Headland LR, Díaz-Ramos LA, Morales LO, Strid Å, Jenkins GI (2019) Regulation of Arabidopsis gene expression by low fluence rate UV-B independently of UVR8 and stress signaling. Photochem Photobiol Sci. doi: 10.1039/c9pp00151d
Open Access
This UK-Swedish collaboration is led by Andrew O’Hara from the Jenkins lab in the University of Glasgow. They continue the lab focus on the UV-B receptor UVR8, in this case performing a transcriptomic analysis of wildtype and uvr8 mutants grown under low UV-B fluence rates. They analyse one differentially expressed gene in more detail, the transcription factor ARABIDOPSIS NAC DOMAIN CONTAINING PROTEIN 13 (ANAC13), which was induced by UV-B but by the activity of any other photoreceptor.
Gumber HK, McKenna JF, Tolmie AF, Jalovec AM, Kartick AC, Graumann K, Bass HW (2019) MLKS2
is an ARM domain and F-actin-associated KASH protein that functions in
stomatal complex development and meiotic chromosome segregation Nucleus. doi: 10.1080/19491034.2019.1629795
Open Access
Hardeep Gumber is first author on this US-led study that includes Joe KcKenna, Andrea Tolmie and Katja Graumann from Oxford Brookes as co-authors. They characterise the Maize LINC KASH AtSINE-like2 protein, MLKS2, whose targeting to the nuclear periphery requires its N-terminal armadillo repeats. Mutant mlks2 plants have pleiotropic plant phenotypes and on a nuclear level show defects in chromosome segregation and positioning. These findings support a model in which cytoplasmic actin is linked to chromatin through the LINC-KASH nuclear envelope network.
Temple H, Mortimer JC, Tryfona T, Yu X, Lopez-Hernandez F, Sorieul M, Anders N, Dupree P (2019) Two members of the DUF579 family are responsible for arabinogalactan methylation in Arabidopsis. Plant Direct. doi: 10.1002/pld3.117
Open Access
Henry Temple is first author on this work from the University of Cambridge that characterizes two members of the DUF579 family (AGM1 and AGM2). These proteins are required for 4-O-methylation of glucuronic acid within highly glycosylated arabinogalactan proteins (AGPs).
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