Weeding the Gems

Arabidopsis Research Round-up

It’s all about Norwich Research Park this week as Jonathan Jones, Dan MacLean (The Sainsbury Laboratory) and Caroline Dean (John Innes Centre) take the lead on this week’s papers. As a bonus, they’re all open access!

• Sohn KH, Segonzac C, Rallapalli G, Sarris PF, Woo JY, Williams SJ, Newman TE, Paek KH, Kobe B and Jones JDG. The nuclear immune receptor RPS4 is required for RRS1^SLH1-dependent constitutive defense activation in Arabidopsis thaliana. PLOS Genetics, 23 October 2014. DOI: 10.1371/journal.pgen.1004655. [Open Access]

While it is known that plant nucleotide-binding leucine-rich repeat (NB-LRR) disease resistance proteins recognise specific ‘avirulent’ pathogen effectors and activate immune responses, the mechanisms by which they do this are not well understood. This article challenges previous hypotheses and advances our understanding of how immune receptors activate defense in Arabidopsis.

• Younsi R and MacLean D. Using 2k + 2 bubble searches to find single nucleotide polymorphisms in k-mer graphs. Bioinformatics, 24 October 2014.DOI: 10.1093/bioinformatics/btu706. [Open Access]

In this Bioinformatics paper, Younsi and MacLean from The Sainsbury Laboratory describe how they used sequence data from 16 Arabidopsis thaliana ecotypes to test and validate an algorithm capable of accurately detecting single nucleotide polymorphisms from de Bruijn graphs.

• Csorba T, Questa JI, Sun Q and Dean C. Antisense COOLAIR mediates the coordinated switching of chromatin states at FLC during vernalization.Proceedings of the National Academy of Sciences of the USA, 27 October 2014. DOI: 10.1073/pnas.1419030111. [Open Access]

In previous work, Caroline Dean and colleagues from the John Innes Centre showed that expression of FLOWERING LOCUS C (FLC) is regulated epigenetically by modifications to the histones: accumulation of H3K36me6 causes FLC to be expressed, thus applying a ‘brake’ to flowering, while accumulation of H2K27me3 removes the brake. However, this is not the whole story, and now the Dean lab has identified another component of the mechanism – antisense non-coding RNA transcripts calledCOOLAIR.

You can read more about this story in this press release: Plants require COOLAIR to flower in spring.