18th Jul 2017

This weeks Arabidopsis Research Roundup includes four studies from around the UK. Firstly is a systems-level study of the drought response that includes Alessandra Devoto from RHUL as a co-author. Secondly Anne Osbourn’s group at the JIC investigates sesterterpenoid biosynthesis across plant species. Thirdly Paul Jarvis from Oxford University adds to this groups portfolio of research on the mechanisms that control thylakoid import. Finally Patrick Gallois (University of Manchester) provides further insight into the regulation of programmed cell death.

Kim JM, To TK et al (2017) Acetate-mediated novel survival strategy against drought in plants Nature Plants http:/​/​dx.​doi.​org/10.1038/nplants.2017.97

Open with URL.

Alessandra Devoto (Royal Holloway) is a co-author of this study led by Jong-Myong Kim, Mototaki Seki (RIKEN, Yokohama) and Taiko Kim Ko (University of Toyko) that investigates the system-wide alterations that plants make in response to drought stress. They demonstrate that the histone deacetylase HDA6 is the primary regulator of an epigenetic switch that leads to a metabolic flux conversion from glycolysis into acetate synthesis. This in turn stimulates the jasmonate signaling pathway that causes increased drought tolerance. Importantly the authors show that this critical survival response is evolutionarily conserved through monocots and dicots.

Huang AC, Kautsar SA, Hong YJ, Medema MH, Bond AD, Tantillo DJ, Osbourn A (2017) Unearthing a sesterterpene biosynthetic repertoire in the Brassicaceae through genome mining reveals convergent evolution. PNAS http:/​/​dx.​doi.​org/10.1073/pnas.1705567114

Open Access

Anne Osbourn (JIC) leads this study in which her group works with collaborators from Cambridge, Wageningen and UC Davis to perform a cross-species genome-wide analysis of sesterterpenoid biosynthesis. They use a novel search algorithm to identify paired enzymatic components that comprise sesterterpene synthases (STS). These enzymes were transiently overexpressed in tobacco leaves, resulting in the formation of fungal-like sesterterpenes, suggestive of convergent evolution of plant and fungal STS. This study illuminates possible future strategies for the beneficial use of sesterterpenes through metabolic and protein engineering

Bédard J, Trösch R, Wu F, Ling Q, Flores-Pérez Ú, Töpel M, Nawaz F, Jarvis P (2017) New Suppressors of the Chloroplast Protein Import Mutant tic40 Reveal a Genetic Link between Protein Import and Thylakoid Biogenesis. Plant Cell. http:/​/​dx.​doi.​org/10.1105/tpc.16.00962 Open Access

Paul Jarvis (Oxford University) leads this global collaboration that focuses on the chloroplast protein import protein Tic40. A suppressor screen identified two novel regulators of Tic40, ALB4 and STIC2 that they postulate are involved in the thylakoid targeting of a subset of proteins and that their influence becomes more important in the absence of Tic40.

Cai YM, Yu J, Ge Y, Mironov A, Gallois P (2017) Two proteases with caspase-3-like activity, cathepsin B and proteasome, antagonistically control ER-stress-induced programmed cell death in Arabidopsis. New Phytol. 

http:/​/​dx.​doi.​org/10.1111/nph.14676 Open Access

Patrick Gallois is the corresponding author on this study that originates at the University of Manchester. They attempt to establish a role for cathepsin B and proteasome subunit PBA1 in the control of programmed cell death (PCD) and whether their functions interest with those of caspase-3. They reveal a complex system of regulation where aspects of PCD are differentially impacted by each of these proteins. They propose the role of cathepsin B might occur late in PCD following tonoplast rupture.