A non canonical subtilase attenuates the transcriptional activation of defence responses in Arabidopsis thaliana

eLife

Alain Jauneau¹  Cécile Pouzet¹  Irene Serrano²  Pierre Buscaill²  Susana Rivas²  Corinne Audran² 

[1] Fédération de Recherche 3450, Plateforme Imagerie, Pôle de Biotechnologie Végétale, Castanet-Tolosan, France;LIPM, Université de Toulouse, INRA, CNRS, Castanet-Tolosan, France;

关键词: transcription factors;    plant defence;    alternative splicing;    subtilase;    hypersensitive response;   

DOI  :  10.7554/eLife.19755

来源: DOAJ

【 摘 要 】

Proteases play crucial physiological functions in all organisms by controlling the lifetime of proteins. Here, we identified an atypical protease of the subtilase family [SBT5.2(b)] that attenuates the transcriptional activation of plant defence independently of its protease activity. The SBT5.2 gene produces two distinct transcripts encoding a canonical secreted subtilase [SBT5.2(a)] and an intracellular protein [SBT5.2(b)]. Concomitant to SBT5.2(a) downregulation, SBT5.2(b) expression is induced after bacterial inoculation. SBT5.2(b) localizes to endosomes where it interacts with and retains the defence-related transcription factor MYB30. Nuclear exclusion of MYB30 results in its reduced transcriptional activation and, thus, suppressed resistance. sbt5.2 mutants, with abolished SBT5.2(a) and SBT5.2(b) expression, display enhanced defence that is suppressed in a myb30 mutant background. Moreover, overexpression of SBT5.2(b), but not SBT5.2(a), in sbt5.2 plants reverts the phenotypes displayed by sbt5.2 mutants. Overall, we uncover a regulatory mode of the transcriptional activation of defence responses previously undescribed in eukaryotes.

【 授权许可】

Unknown