Weeding the Gems

Here’s your Arabidopsis Research Round-up for this week! Today we have plenty of Scottish delights, including papers from the University of Aberdeen, Dundee,Glasgow, Edinburgh and the James Hutton Institute. There is also new work from researchers at the University of Durham, Nottingham, Leeds and Oxford.

• Pokhilko A, Bou-Torrent J, Pulido P, Rodrígues-Concepción M and Ebenhöh O. Mathematical modelling of the diurnal regulation of the MEP pathway in Arabidopsis. New Phytologist, 16 January 2015. DOI: 10.1111/nph.13258.

Alexandra Pokhilko and Oliver Ebenhöh are two members of the University of Aberdeen’s Institute for Complex Systems and Mathematical Biology. Both contributed to this New Phytologist paper, in which they describe a mathematical model of the diurnal regulation of the 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway. Data show that flux through the MEP pathway is accelerated in light conditions. It is also shown that pathway products regulate the abundance and activity of DXS (the first enzyme in the pathway, 1-deoxy-d-xylulose 5-phosphate synthase), which alters flux under varying conditions.

• McCormick AJ and Kruger NJ. Lack of fructose 2,6-bisphosphate compromises photosynthesis and growth in Arabidopsis in fluctuating environments. The Plant Journal, 20 January 2015. DOI: 10.1111/tpj.12765.

Here, Alistair McCormick from SynthSys at the University of Edinburgh and Nick Kruger from the University of Oxford describe their research on understanding the physiological role of the signal metabolite fructose 2,6-bisphosphate (Fru-2,6-P₂). Plants from three independent T-DNA mutant lines deficient in 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (F2KP) grow normally in constant environments, but have reduced growth and seed yield in fluctuating light and/or temperatures. McCormick and Kruger suggest that Fru-2,6-P₂ is involved in the modulation of photoassimilate partitioning, and that this is an important determinant of growth and fitness in natural environments.

• Calixto CPG, Waugh R and Brown JWS. Evolutionary relationships among barley and Arabidopsis core circadian clock and clock-associated genes.Journal of Molecular Evolution, 22 January 2015. DOI: 10.1007/s00239-015-9665-0.

Presented by scientists from the James Hutton Institute and the University of Dundee, this paper provides a comprehensive analysis of circadian clock and clock-associated genes in Arabidopsis thaliana, barley, and eight other plant species. It is proposed that the common ancestor of Arabidopsis and barley had two-thirds of the key clock components identified in Arabidopsis prior to the divergence of monocot and dicot groups.

• Verma V, Sivaraman J, Srivastava AK, Sadanandom A and Kumar PP. Destabilization of interaction between cytokinin signalling intermediates AHP1 and ARR4 modulates Arabidopsis development. New Phytologist, 30 January 2015. DOI: 10.1111/nph.13297.

Working with Singaporean colleagues, this New Phytologist paper involved the work of Ari Sadanandom from the University of Durham. The group describe their research on the previously poorly understood relationship between histidine phosphotransfer proteins (e.g. AHP1) and response regulator proteins (e.g. ARR4 ).

• Wilson MH, Holman TJ, Sørensen I, et al. Multi-omics analysis identifies genes mediating the extension of cell walls in the Arabidopsis thaliana root elongation zone. Frontiers in Cell & Developmental Biology, 2 February 2015. DOI: 10.3389/fcell.2015.00010. [Open Access]

Scientists from the University of Leeds and the University of Nottingham (including former GARNet committee member Malcolm Bennett) here describe a multi-omics approach to understanding the regulation of cell wall extension in Arabidopsis roots.

• Preuten T, Blackwood L, Christie JM and Fankhauser C. Lipid anchoring of Arabidopsis phototropin 1 to assess the functional significance of receptor internalization: should I stay or should I go? New Phytologist, 3 February 2015. DOI: 10.1111/nph.13299.

John Christie and student Lisa Blackwood from the University of Glasgow were involved in another New Phytologist paper, led by a Swiss team from Lausanne. The group is attempting to work out why, when irradiated, a fraction of the plasma membrane-associated phototropin 1 (phot1) blue light receptor is internalized into the cytoplasm. Transgenic plants expressing a lipidated version of phot1 permanently anchored to the plasma membrane were used to assess the effect of internalisation on receptor turnover, phototropism and other phot1-mediated effects, however, data suggest that internalisation is not linked to receptor turnover or desensitisation.