Coronatine orchestrates ABI1-mediated stomatal opening to facilitate bacterial pathogen infection through importin β protein SAD2

Lu Liu; Yanzhi Liu; Xuehan Ji; Xia Zhao; Jun Liu; Ning Xu

doi:10.1111/tpj.16784

Coronatine orchestrates ABI1-mediated stomatal opening to facilitate bacterial pathogen infection through importin β protein SAD2

Plant J. 2024 Apr 29. doi: 10.1111/tpj.16784. Online ahead of print.

Authors

Lu Liu¹, Yanzhi Liu², Xuehan Ji¹, Xia Zhao¹, Jun Liu¹, Ning Xu¹

Affiliations

¹ State Key Laboratory of Agrobiotechnology and MOA Key Laboratory for Monitoring and Green Management of Crop Pests, China Agricultural University, Beijing, China.
² Chinese Academy of Sciences (CAS) Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, University of CAS, Chinese Academy of Sciences, Shanghai, China.

PMID: 38683723
DOI: 10.1111/tpj.16784

Abstract

Stomatal immunity plays an important role during bacterial pathogen invasion. Abscisic acid (ABA) induces plants to close their stomata and halt pathogen invasion, but many bacterial pathogens secrete phytotoxin coronatine (COR) to antagonize ABA signaling and reopen the stomata to promote infection at early stage of invasion. However, the underlining mechanism is not clear. SAD2 is an importin β family protein, and the sad2 mutant shows hypersensitivity to ABA. We discovered ABI1, which negatively regulated ABA signaling and reduced plant sensitivity to ABA, was accumulated in the plant nucleus after COR treatment. This event required SAD2 to import ABI1 to the plant nucleus. Abolition of SAD2 undermined ABI1 accumulation. Our study answers the long-standing question of how bacterial COR antagonizes ABA signaling and reopens plant stomata during pathogen invasion.

Keywords: ABI1; Arabidopsis thaliana; Pst DC3000; SAD2; coronatine; importin β; stomatal immunity.

Abstract

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