ARABIDOPSIS RESEARCH ROUND-UPARABIDOPSIS RESEARCH ROUND-UP

13th Aug 2014

The GARNet team is now back from its conference travels after attending the International Conference on Arabidopsis Research in Vancouver two weeks ago. Charis and I then stayed in Vancouver for a few days’ holiday, but now we’re back in the office and I need to catch up on the Arabidopsis Research Round-up! There’s been lots published while we’ve been away, so to avoid overloading you with too many papers at once, here’s a recap on some of the newest UK papers published in from early to mid July. I’ll do another double bill next week!

 

  • Hachez C, Laloux T, Reinhardt H et al. Arabidopsis SNAREs SYP61 and SYP121 coordinate the trafficking of plasma membrane aquaporin PIP2;7 to modulate the cell membrane water permeability. The Plant Cell, 8 July 2014. DOI: 10.1105/tpc.114.127159.

Mike Blatt from the University of Glasgow was involved in this neat little study, in which it is shown that interaction with two syntaxin proteins is required for post-Golgi trafficking of PIP2;7, a plasma membrane intrinsic protein involved in the movement of water and small solutes through membranes. It is also shown that the syntaxins, SYP61 and SYP121 (both SNAREs), physically interact with each other as well as PIP2;7, thus suggesting that a SNARE complex is formed.

 

  • Petutschnig EK, Stolze M, Lipka U et al. A novel Arabidopsis CHITIN ELICITOR RECEPTOR KINASE 1 (CERK1) mutant with enhanced pathogen-induced cell death and altered receptor processing. New Phytologist, 10 July 2014. DOI: 10.1111/nph.12920.

Members of the Sainsbury Lab in Norwich worked on this paper in New Phytologist. Here, a new Arabidopsis mutant is characterised, in which an amino acid change in the CERK1 ectodomain causes plants to maintain chitin signaling, but show hyper-inducible salicylic acid concentrations and deregulated cell death upon pathogen challenge. Study of the wild type CERK1 protein reveals that it undergoes ectodomain shedding; the report of this process in plants.

 

  • Chen C-W, Panzeri D, Yeh Y-H et al. The Arabidopsis malectin-like leucine-rich repeat receptor-like kinase IOS1 associates with thepatterm recognition receptors FLS2 and EFR and is critical for priming of pattern-triggered immunity. The Plant Cell, 13 July 2014. DOI: 10.1105/tpc.114.125682.

This Plant Cell paper was produced in collaboration between researchers from Taiwan and the Sainsbury Lab in Norwich, including our very own GARNet committee member Cyril Zipfel. This work reveals more information about the role of IMPAIRED OOMYCETE SUSCEPTIBILITY1 (IOS1) in the regulation of plasma membrane-localised pattern recognition receptors that prime pattern-triggered immunity (PTI) in Arabidopsis thaliana. ios1 mutants  were hypersusceptible to Pseudomonas syringae infection, and showed defective PTI responses, while IOS1 overexpressing lines showed increased resistance to P. syringae and were primed for PTI. 

 

  • Busse-Wicher M, Gomes TCF, Tryfona T, Nikolovski N, Stott K, Grantham NJ, Bolam DN, Skaf MS and Dupree P. The pattern of xylan acetylation suggests xylan may interact with cellulose microfibrils as a twofold helical screw in the secondary plant cell wall of Arabidopsis thaliana. The Plant Journal, 15 July 2014. DOI: 10.1111/tpj.12575. [Open Access]

In the ongoing quest to resolve the biochemical structures of secondary cell walls, important for advancing our knowledge to develop efficient biofuels, this paper from scientists at the Universities of Cambridge, Newcastle, and Campinas in Brazil adds to our understanding of xylan-cellulose interactions and their importance.  Here, the group investigates the arrangement of acetyl residues in xylan to determine the effects on conformation architecture and stability.

 

  • Canizares MC, Rosas-Diaz T, Rodriguez-Negrete E, Hogenhout SA, Bedford D, Bejarano ER, Navas-Castillo J and Moriones E. Arabidopsis thaliana, an experimental host for tomato yellow leaf curl disease-associated begomoviruses by agroinoculation and whitefly transmission. Plant Pathology, 16 July 2014. DOI: 10.1111/ppa.12270.

Saskia Hogenhout and Ian Bedford from the John Innes Centre were collaborators on this Spanish-led paper in Plant Pathology. The study identifies that Arabidopsis thaliana can be infected by two isolate strains of tomato yellow leaf curl viruses (TYLCV), and as such is a suitable host for studying TYLCV­–insect vector–plant host interaction studies. A particularly Spanish strain of the virus was found to be unable to infect Arabidopsis thaliana however. This information has been used to identify which viral factors are required for infection.

 

  • Li P, Filiault D, Box MS et al. Multiple FLC haplotypes defined by indepent cis-regulatory variation underpin life history diversity in Arabidopsis thaliana. Genes & Development, 17 July 2014. DOI: 10.1101/gad.245993.114. [Open Access]

Norwich is well represented in this week’s Round-up! Here’s another paper involving scientists from the John Innes Centre, University of East Anglia and The Genome Analysis Centre, together with US and Austrian colleagues. The paper discusses the findings of the analysis of 1307 Arabidopsis accessions, in which five predominant haplotypes of natural variation in the FLC locus are identified. The extensive allelic heterogeneity present in this floral repressor gene can account for a good proportion of the natural variation in vernalisation rate in Arabidopsis thaliana.

 

  • Kumpf R, Thorstensen T, Rahman MA et al. The ASHR3 SET-domain protein controls cell division competence of the meristem and quiescent centre of the Arabidopsis thaliana primary root. Plant Physiology, 17 July 2014. DOI: 10.1104/pp.114.244798. [Open Access]

GARNet committee member Malcolm Bennett from the University of Nottingham appears on this Plant Phys paper, as does his colleague Ranjan Swarup and collaborators from Oslo and Ghent. Seeking to understand more about the cell division that takes place in primary root stem cells before they switch to differentiation, the team identifies that the ASH RELATED3 (ASHR3) gene is involved in the synchronization of stem cell replication and cell division. The non-stochastic pattern of cell division seen in the wild type is disrupted in ASHR3 mutant lines, which also show increased cell division in the quiescent centre.

 

  • Ali MA, Wieczorek K, Kreil DP and Bohlmann H. The beet cyst nematode Heterodera schachtii modulates the expression of WRKY transcription factors in syncytia to favor its development in Arabidopsis roots. PLOS ONE, 17 July 2014. DOI: 10.1371/journal.pone.0102360. [Open Access]

Working with colleagues from Austria and Pakistan, this PLOS ONE paper also features David Kreil from the University of Warwick. In this study, the group compared the transcriptomes of syncytia induced by invasion of the beet cyst nematode Heterodera schachtii with regular Arabidopsis root tissue. They found that a great many WRKY genes were down-regulated, and studied four of these in detail. Down-regulation of WRKY genes seems to be important for nematode development, in particular through interference with plant defense reactions.