ARABIDOPSIS RESEARCH ROUND-UPARABIDOPSIS RESEARCH ROUND-UP

5th Mar 2014

A mixed bag of new Arabidopsis papers for you this week, including characterisation of a virulence effector, further understanding of the mechanism of stomatal closure in response to UV-B, evidence to suggest that PAMP-triggered immunity is important in providing plant defence against aphids as well as microbes, and a Systems Biology advance in transcription thermodynamics – enjoy!  

 

  • Sugio A, MacLean AM and Hogenhout SA. The small phytoplasma virulence effector SAP11 contains distincy domains required or nuclear targeting and CIN-TCP binding and destablization. New Phytologist, 19 February 2014. DOI: 10.1111/nph.12721.

This paper from the Hogenhout lab at the John Innes Centre builds on previous work, in which it was discovered that the virulence effector SAP11 binds to CIN-TCP transcription factors, and subsequently causes changes in leaf morphogenesis and increased susceptibility to phytoplasma insect vectors. Here, further understanding of the function of SAP11 is provided.

 

  • Tossi VE, Lamattina L, Jenkins G and Cassia R. UV-B-induced stomatal closure in Arabidopsis is regulated by the UVR8 photoreceptor in an NO-dependent mechanism. Plant Physiology, 27 February 2014. DOI: ​10.​1104/​pp.​113.​231753. [Open Access]

Gareth Jenkins from the University of Glasgow worked with an Argentinean team on this open access Plant Physiology paper. The team investigated the participation of the UVR8 pathway and its interaction with NO in UV-B-induced stomatal movements in Arabidopsis. It was found that the UVR8 pathway is involved in the closure of stomata via a mechanism involving both NO and H­2O2.

 

  • Prince DC, Drurey C, Zipfel C and Hogenhout S. The leucine-rich repeat receptor-like kinase BAK1 and the cytochrome P450 PAD3 contribute to innate immunity to aphids in Arabidopsis. Plant Physiology, 28 February 2014. DOI: 10.​1104/​pp.​114.​235598. [Open Access]

While PAMP-triggered immunity (PTI) has been demonstrated to provide plants with innate defenses against microbes, there has been little research into whether PTI can also protect against insects. Researchers from the John Innes Centre and the Sainsbury Lab in Norwich – including GARNet committee member Cyril Zipfel – here provide evidence to support the idea that indeed they do, perhaps via early perception of elicitors by cell surface-localised pattern recognition receptors leading to downstream signalling.

 

  • Sidaway-Lee K, Costa MJ, Rand DA, Finkenstadt B and Penfield S. Direct measurement of transcription rates reveals multiple mechanisms for configuration of the Arabidopsis ambient temperature response. Genome Biology, 3 March 2014. DOI: 10.1186/gb-2014-15-3-r45. [Open Access]

The abundance of mRNA in a plant’s transcriptome changes with ambient temperature, but it is unclear whether this is as a result of decreased transcription, or increased mRNA decay. Systems biology researchers from the Universities of Exeter and Warwick used a base analogue labelling method to measure the temperature co-efficient of mRNA synthesis and degradation rates in Arabidopsis. They found that, in fact, increased ambient temperature increases mRNA abundance, but this is buffered by passive increases in mRNA decay (and vice versa).