Stability of small ubiquitin-like modifier (SUMO) proteases OVERLY TOLERANT TO SALT1 and -2 modulates salicylic acid signalling and SUMO1/2 conjugation in Arabidopsis thaliana

Bailey, Mark; Srivastava, Anjil; Conti, Lucio; Nelis, Stuart; Zhang, Cunjin; Florance, Hannah; Love, Andrew; Milner, Joel; Napier, Richard; Grant, Murray; Sadanandom, Ari

Abstract

Small ubiquitin-like modifier proteases 1 and 2 (SUMO1/2) have been linked to the regulation of salicylic acid (SA)-mediated defence signalling in Arabidopsis thaliana. In order to define the role of the SUMO proteases OVERLY TOLERANT TO SALT1 and -2 (OTS1/2) in defence and to provide insight into SUMO1/2-mediated regulation of SA signalling, we examined the status of SA-mediated defences in ots1/2 mutants. The ots1 ots2 double mutant displayed enhanced resistance to virulent Pseudomonas syringae and higher levels of SA compared with wild-type (WT) plants. Furthermore, ots1 ots2 mutants exhibited upregulated expression of the SA biosynthesis gene ICS1 in addition to enhanced SA-responsive ICS1 expression beyond that of WT. SA stimulated OTS1/2 degradation and promoted accumulation of SUMO1/2 conjugates. These results indicate that OTS1 and -2 act in a feedback loop in SA signalling and that de novo OTS1/2 synthesis works antagonistically to SA-promoted degradation, adjusting the abundance of OTS1/2 to moderate SA signalling. Accumulation of SUMO1/2 conjugates coincides with SA-promoted OTS degradation and may play a positive role in SA-mediated signalling in addition to its repressive roles reported elsewhere.

Citation

Bailey, M., Srivastava, A., Conti, L., Nelis, S., Zhang, C., Florance, H., …Sadanandom, A. (2016). Stability of small ubiquitin-like modifier (SUMO) proteases OVERLY TOLERANT TO SALT1 and -2 modulates salicylic acid signalling and SUMO1/2 conjugation in Arabidopsis thaliana. Journal of Experimental Botany, 67(1), 353-363. https://doi.org/10.1093/jxb/erv468

• Journal Article Type: Article
• Acceptance Date: Oct 5, 2015
• Online Publication Date: Oct 22, 2015
• Publication Date: Jan 1, 2016
• Deposit Date: Nov 2, 2015
• Publicly Available Date: Nov 3, 2015
• Journal: Journal of Experimental Botany
• Print ISSN: 0022-0957
• Electronic ISSN: 1460-2431
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 67
• Issue: 1
• Pages: 353-363
• DOI: https://doi.org/10.1093/jxb/erv468
• Keywords: Arabidopsis thaliana, Defence, Pathogen, Salicylic acid (SA), Small ubiquitin-like modifier (SUMO), SUMO protease, SUMOylation.
• Public URL: https://durham-repository.worktribe.com/output/1427568