This edition of the GARNet Research Roundup is led by two papers from John Christie’s lab at the University of Glasgow. First is a study that looks at the function of the NPH3 protein during phototropism whilst the second paper is a collaboration with Mike Blatt’s group and has used an synthetic biology approach to increase plant biomass by altering stomatal conductance.
Third is a paper from the University Dundee and James Hutton Institute that looks at the extent of alternative splicing of long non-coding RNAs in response to cold stress.
The fourth paper is from Royal Holloway and defines the role of a MAP kinase module during meristem development. The fifth paper is led by Charles Spillane in Galway and includes Mary O’Connell at the University of Nottingham as a co-author and investigates the selective pressures that are applied to parentally imprinted genes.
The penultimate paper is from Aberystwyth and uses microCT imaging to determine grain parameters in wheat and barley whilst the final paper is from Queens Mary University of London looks at nonphotochemical quenching in Berteroa incana.
Sullivan S, Kharshiing E, Laird J, Sakai T, Christie J (2019) De-etiolation Enhances Phototropism by Modulating NON-PHOTOTROPIC HYPOCOTYL 3 Phosphorylation Status. Plant Physiol. doi: 10.1104/pp.19.00206
Stuart Sullivan is first author on this work from John Christie’s lab
at the University of Glasgow in which they investigate the functional
significance of dephosphorylation of the NON-PHOTOTROPIC HYPOCOTYL 3
(NPH3) protein that occurs following activation of Phototropin receptor
kinases. They show that plant greening (de-etiolation) enhances
phototropic responses that are coincident with reduced NPH3
dephosphorylation and increased plasma membrane retention of the
protein. They further investigate other genetic and environmental
factors that impact NPH3 dephosphorylation, which allows young seedlings
to maximise their establishment under changing light conditions.
Papanatsiou M, Petersen J, Henderson L, Wang Y, Christie JM, Blatt MR (2019) Optogenetic manipulation of stomatal kinetics improves carbon assimilation, water use, and growth. Science. doi: 10.1126/science.aaw0046
Maria Papanatsiou is lead author on this work from the University of Glasgow that occured in the labs of Mike Blatt
and John Christie. They aimed to address a phenomonen that occurs
during changing environmental conditions in which stomatal dynamics lag
behind biochemical photosynthetic changes. This prevents plants from
maximising their outputs due to inefficiencies in gas and water
exchange. In this work they express a synthetic blue light-gated K+
channel BLINK1 in guard cells. This introduced a K+ conductance to these
cells resulting in accelerated stomatal opening under light exposure
and closing after irradiation. Ultimately they show that this
significantly increases biomass without incurring a water use cost. This
approach has clear potential for improving plant productivity under
changing environmental conditions.
Calixto CPG, Tzioutziou NA, James AB, Hornyik C, Guo W, Zhang R, Nimmo HG, Brown JWS (2019) Cold-Dependent Expression and Alternative Splicing of Arabidopsis Long Non-coding RNAs. Front Plant Sci. doi: 10.3389/fpls.2019.00235
Calixto and John Brown from the University of Dundee and the James
Hutton Institute lead this study into alternative splicing of lncRNAs in
response to cold. This is a follow-up to their large scale scale study
on the extent of alternative splicing in Arabidopsis.
The authors identified 135 lncRNA genes with cold-dependent
differential expression (DE) and/or differential alternative splicing
(DAS), some of which were highly sensitive to small temperature changes.
This system identified a set of lncRNAs that could be targets for
future research aimed at understanding how plants respond to cold and
Dóczi R, Hatzimasoura E, Farahi Bilooei S, Ahmad Z, Ditengou FA, López-Juez E, Palme K, Bögre L (2019) The MKK7-MPK6 MAP Kinase Module Is a Regulator of Meristem Quiescence or Active Growth in Arabidopsis. Front Plant Sci. doi: 10.3389/fpls.2019.00202
is the first author on this UK, Hungarian and German collaboration that
is led from Royal Holloway University of London. They use genetic
approaches to show that the MKK7-MPK6 MAP kinase module is a suppressor
of meristem activity. They use mkk7 and mpk6 mutants as
well as overexpression lines to demonstrate that perturbation of the
MAPK signaling pathway alters both shoot and root meristem development
and plays important roles in the control of plant developmental
Tuteja R, McKeown PC, Ryan P, Morgan CC, Donoghue MTA, Downing T, O’Connell MJ, Spillane C (2019) Paternally expressed imprinted genes under positive Darwinian selection in Arabidopsis thaliana. Mol Biol Evol. doi: 10.1093/molbev/msz063
Reetu Tuteja from the National University of Ireland at Galway is first author on this paper that includes Mary O’Connell from the University of Nottingham.
The authors used Arabidopsis to look at 140 endosperm-expressed genes
that are regulated by genomic imprinting and found that they were
evolving more rapidly than expected. This investigation was extended
across 34 other plant species and they found that paternally, but not
maternally imprinted genes were under positive selection, indicating
that imprinted genes of different parental origin were subject to
different selective pressures. This data supports a model wherein
positive selection effects paternally-expressed genes that are under
continued conflict with maternal sporophyte tissues.
Hughes N, Oliveira HR, Fradgley N, Corke FMK, Cockram J, Doonan JH, Nibau C (2019) μCT trait analysis reveals morphometric differences between domesticated temperate small grain cereals and their wild relatives. Plant J doi: 10.1111/tpj.14312
Nathan Hughes and Candida Nibau at the Aberystwyth University lead
this work that uses microCT imaging alongside novel image analysis
techniques and mathematical modeling to assess grain size and shape
across accessions of wheat and barley. They find that grain depth is a
major driver of shape change and that it is also an excellent predictor
of ploidy levels. In addition they have developed a model that enables
the prediction of the origin of a grain sample from measurements of its
length, width and depth.
Wilson S, Ruban AV (2019) Enhanced NPQ affects long-term acclimation in the spring ephemeral Berteroa incana. Biochim Biophys Acta Bioenerg. doi: 10.1016/j.bbabio.2019.03.005
This study is led by Sam Wilson and Alexander Ruban at QMUL and investigates nonphotochemical quenching in the Arabidopsis-relative Berteroa incana. They show that light tolerance and ability to recover from light stress is greatly enhanced in Berteroa compared to Arabidopsis. This is due to faster synthesis of zeaxanthin and a larger xanthophyll cycle (XC) pool available for deepoxidation. This result gives B.incana a greater capacity for protective NPQ allowing enhanced light-harvesting capability when acclimated to a range of light conditions. The authors suggest this short-term protection prevents the need for the metabolic toll of making long-term acclimations.