This edition of the GARNet Research Roundup includes a superb selection of papers by scientists from across the UK. First is work from the Spoel lab in Edinburgh that characterizes the fine-tuning of NPR1 activity during the plant immune response. Second is work from SLCU and the University of Helsinki that is an extensive investigation into the molecular basis of cambial development. Next is research from Nottingham that looks at the importance of soil macro-structures during the growth of wheat roots.
Fourth are three papers that highlight the breadth of research occurring at the John Innes Centre. The first paper is from Enrico Coen’s lab that applies their expertise in computational modeling to leaf development in the carnivorous plant Utricularia gibba. Second is work from Saskia Hogenhout’s lab that looks at immunity to infection by Phytoplasma pathogens. Last is work from Lars Ostergaard’s lab that characterises the role of Auxin Binding promoter elements in floral development.
The seventh paper from Bristol and Glasgow looks at shade avoidance signaling via PIF5, COP1 and UVR8 whilst the eighth paper, which is from Rothamsted, demonstrates how metabolic engineering in Arabidopsis seeds can result in a high proportion of human milk fat substitute. The next paper is from the University of Durham and investigates how the composition of the Arabidopsis cell wall impacts freezing tolerance. The first author of this paper, Dr Paige Panter discusses the paper on the GARNet community podcast.
The tenth paper is from Julia Davies’s lab at the University of Cambridge and introduces an uncharacterised response to extracellular ATP signals in Arabidopsis roots. The next paper is from Mike Blatt’s group at University of Glasgow and characterises a new interaction between vesicular transport and ion channels. The penultimate entry includes co-authors from the JIC on a Chinese-led study that demonstrates improved seed vigour in wheat through overexpression of a NAC transcription factor. Finally are two methods papers taken from a special journal issue on ‘Plant Meiosis’.
Skelly MJ, Furniss JJ, Grey HL, Wong KW, Spoel SH (2019) Dynamic ubiquitination determines transcriptional activity of the plant immune coactivator NPR1. Elife. doi: 10.7554/eLife.47005
Michael Skelly is lead author on this paper from the lab of current GARNet chair Steven Spoel.
In it they investigate the mechanisms that fine-tune the function of
NPR1, a key player in the plant immune response. Progressive
ubiquitination of NPR1 by an E3 ligase causes both its interaction with
target genes and its subsequent degradation by an E4 ligase. This latter
occurrence is opposed by the deubiquitinase activity of UBP6/7, setting
up a complex regulatory environment that allows the plant to rapidly
response to pathogen attack.
Zhang J, Eswaran G, Alonso-Serra J, Kucukoglu M, Xiang J, Yang W, Elo A, Nieminen K, Damén T, Joung JG, Yun JY, Lee JH, Ragni L, Barbier de Reuille P, Ahnert SE, Lee JY, Mähönen AP, Helariutta Y (2019) Transcriptional regulatory framework for vascular cambium development in Arabidopsis roots. Nat Plants. doi: 10.1038/s41477-019-0522-9
This pan-European-Korean collaboration has Jing Zhang from the University of Helsinki and the Sainsbury Laboratory, University of Cambridge as first author. They use cambium cell-specific transcript profiling and follow-on network analysis to discover 62 new transcription factors involved in cambial development in Arabidopsis. This information was used to engineer plants with increased radial growth through ectopic cambial activity as well as to generate plants with no cambial activity. This understanding provides a platform for possible future improvements in production of woody biomass.
Atkinson JA, Hawkesford MJ, Whalley WR, Zhou H, Mooney SJ (2019) Soil strength influences wheat root interactions with soil macropores. Plant Cell Environ. doi: 10.1111/pce.13659
This work is led from the University of Nottingham by John Atkinson and Sacha Mooney.
They use X-ray Computed Tomography to investigate a trait called
trematotropism, which applies to the ability of deep rooting plants to
search out macropores and avoid densely packed soil. They show root
colonisation of macropores is an important adaptive trait and that
strategies should be put in place to increase these structures within
the natural soil environment.
Lee KJI, Bushell C, Koide Y, Fozard JA, Piao C, Yu M, Newman J, Whitewoods C, Avondo J, Kennaway R, Marée AFM, Cui M, Coen E (2019) Shaping of a three-dimensional carnivorous trap through modulation of a planar growth mechanism. PLoS Biol. doi: 10.1371/journal.pbio.3000427
Karen Lee, Claire Bushell and Yohei Koide are co-first authors on this work led by Enrico Coen at the John Innes Centre and Minlong Cui at the Zhejiang Agriculture and Forestry University in China. This study uses 3D imaging, cellular and clonal analysis, combined with computational modelling to analyse the development of cup-shaped traps of the carnivorous plant Utricularia gibba. They identify growth ansiotrophies that result in the final leave shape that develops from an initial near-spherical form. These processes have some similarities to the polar growth seen in Arabidopsis leaves. Overall they show that ‘simple modulations of a common growth framework underlie the shaping of a diverse range of morphologies’.
Pecher P, Moro G, Canale MC, Capdevielle S, Singh A, MacLean A, Sugio A, Kuo CH, Lopes JRS, Hogenhout SA (2019) Phytoplasma
SAP11 effector destabilization of TCP transcription factors
differentially impact development and defence of Arabidopsis versus
maize. PLoS Pathog. doi: 10.1371/journal.ppat.1008035
This work from Saskia Hogenhout’s
lab at the John Innes Centre is led by Pascal Pecher and Gabriele Moro.
They look at the effect of SAP11 effectors from Phytoplasma species
that infect either Arabidopsis or maize. They demonstrate that although
both related versions of SAP11 destabilise plant TCP transcription
factors, their modes of action have significant differences. Please look
out for Saskia discussing this paper on the GARNet Community podcast
Kuhn A, Runciman B, Tasker-Brown W, Østergaard L 92019) Two Auxin Response Elements Fine-Tune PINOID Expression During Gynoecium Development in Arabidopsis thaliana. Biomolecules. doi: 10.3390/biom9100526
is first author of this research from Lars Østergaard’s lab at the John
Innes Centre. They functional characterise two Auxin-responsive
Elements (AuxRE) within the promotor of the PINOID gene, which are bound
by the ETITIN/ARF3 Auxin Response Factor. Alteration of this AuxRE
causes phenotypic changes during flower development demonstrating that
even with a complex regulatory environment, small changes to
cis-elements can have significant developmental consequences.
Sharma A, Sharma B, Hayes S, Kerner K, Hoecker U, Jenkins GI, Franklin KA (2019) UVR8 disrupts stabilisation of PIF5 by COP1 to inhibit plant stem elongation in sunlight. Nat Commun. doi: 10.1038/s41467-019-12369-1
is first author of this UK-Spanish-Germany collaboration led by Keara
Franklin at University of Bristol. They have characterised the
interaction between three significant molecular players that function
during the shade avoidance response in Arabidopsis; PIF5, UVR8 and COP1.
In shaded conditions, UVR8 indirectly promotes rapid degradation of
PIF5 through their interactions with the E3 ubiquitin ligase COP1.
van Erp H, Bryant FM, Martin-Moreno J, Michaelson LV, Bhutada G, Eastmond PJ (2019) Engineering the stereoisomeric structure of seed oil to mimic human milk fat. Proc Natl Acad Sci U S A. doi: 10.1073/pnas.1907915116
Harrie Van Arp and Peter Eastmond at Rothamsted Research lead this extremely translational study in which they have modified the metabolic pathway for triacylglycerol (TAG) biosynthesis. By modifying the location of one biosynthesis enzyme and removing the activity of another, the fats produced in these Arabidopsis seeds are enriched to contain TAGs that are similar to those found in human milk. They propose that this technology could be used to develop a source of plant-derived human milk fat substitute.
Kent O, Dale M, Smith SJ, Skipsey M, Thorlby G, Cummins I, Ramsay N,
Begum RA, Sanhueza D, Fry SC, Knight MR, Knight H (2019) MUR1-mediated cell-wall fucosylation is required for freezing tolerance in Arabidopsis thaliana. New Phytol. doi: 10.1111/nph.16209
led this work as part of her PhD at the University of Durham in the lab
of Heather Knight. They characterise the role of the MUR1 protein in
the control of cell wall fucosylation and how this contributes to plant
freezing tolerance. Paige discusses this paper and the long history of
MUR1 on the GARNet Community podcast. Please check it out!
Wang L, Stacey G, Leblanc-Fournier N, Legué V, Moulia B, Davies JM (2019) Early Extracellular ATP Signaling in Arabidopsis Root Epidermis: A Multi-Conductance Process. Front Plant Sci. doi: 10.3389/fpls.2019.01064.
The UK-French collaboration is led by Limin Wang from Julia Davies’s
lab in Cambridge. They use patch clamp electrophysiology to identify
previously uncharacterized channel conductances that respond to
extracellular ATP across the root elongation zone epidermal plasma
Waghmare S, Lefoulon C, Zhang B, Lileikyte E, Donald NA, Blatt MR (2019) K+ channel-SEC11 binding exchange regulates SNARE assembly for secretory traffic. Plant Physiol. doi: 10.1104/pp.19.00919
This work from Mike Blatt’s lab in Glasgow is led by Sakharam Waghmare.
They look at the interaction between SNARE proteins, which are involved
in vesicular fusion and K+ channels, which help control turgor pressure
during cell expansion. Through combining analysis of protein-protein
interactions and electrophysiological measurement they have found that
this interaction requires the activity of the regulatory protein SEC11.
Li W, He X, Chen Y, Jing Y, Shen C, Yang J, Teng W, Zhao X, Hu W, Hu M, Li H, Miller AJ, Tong Y (2019) A wheat transcription factor positively sets seed vigour by regulating the grain nitrate signal. New Phytol. doi: 10.1111/nph.16234
Wenjing Li is first author of this Chinese study that includes Yi Chen and Anthony Miller from the John Innes Centre as co-authors. This research shows that seed vigour and nitrate accumulation in wheat is regulated by the TaNAC2 transcriptions factor through its control of the TaNRT2.5 nitrate transporter. The authors suggest that both genes could be used as potential future targets to increase grain yield and nitrogen use efficiency.
The Special Issue of Methods in Molecular Biology on Plant Meiosis
includes papers from the University of Cambridge, led by Christophe
Lambing and the James Hutton Institute, led by Benoit Darrier.
Lambing C, Choi K, Blackwell AR, Henderson IR (2019) Chromatin Immunoprecipitation of Meiotically Expressed Proteins from Arabidopsis thaliana Flowers. Methods Mol Biol. doi: 10.1007/978-1-4939-9818-0_16
Darrier B, Arrieta M, Mittmann SU, Sourdille P, Ramsay L, Waugh R, Colas I (2019) Following the Formation of Synaptonemal Complex Formation in Wheat and Barley by High-Resolution Microscopy. Methods Mol Biol. doi: 10.1007/978-1-4939-9818-0_15