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Salicylic acid‐mediated innate immunity in Arabidopsis is regulated by SIZ1 SUMO E3 ligase
Author(s) -
Lee Jiyoung,
Nam Jaesung,
Park Hyeong Cheol,
Na Gunnam,
Miura Kenji,
Jin Jing Bo,
Yoo Chan Yul,
Baek Dongwon,
Kim Doh Hoon,
Jeong Jae Cheol,
Kim Donggiun,
Lee Sang Yeol,
Salt David E.,
Mengiste Tesfaye,
Gong Qingqiu,
Ma Shisong,
Bohnert Hans J.,
Kwak SangSoo,
Bressan Ray A.,
Hasegawa Paul M.,
Yun DaeJin
Publication year - 2007
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2006.02947.x
Subject(s) - arabidopsis , pseudomonas syringae , biology , ubiquitin ligase , plant immunity , genetics , jasmonic acid , innate immune system , mutant , plant disease resistance , npr1 , arabidopsis thaliana , gene , systemic acquired resistance , botrytis cinerea , microbiology and biotechnology , botany , ubiquitin , immune system , medicine , heart failure , natriuretic peptide
Summary Reversible modifications of target proteins by small ubiquitin‐like modifier (SUMO) proteins are involved in many cellular processes in yeast and animals. Yet little is known about the function of sumoylation in plants. Here, we show that the SIZ1 gene, which encodes an Arabidopsis SUMO E3 ligase, regulates innate immunity. Mutant siz1 plants exhibit constitutive systemic‐acquired resistance (SAR) characterized by elevated accumulation of salicylic acid (SA), increased expression of pathogenesis‐related ( PR ) genes, and increased resistance to the bacterial pathogen Pseudomonas syringae pv. tomato ( Pst ) DC3000. Transfer of the NahG gene to siz1 plants results in reversal of these phenotypes back to wild‐type. Analyses of the double mutants, npr1 siz1 , pad4 siz1 and ndr1 siz1 revealed that SIZ1 controls SA signalling. SIZ1 interacts epistatically with PAD4 to regulate PR expression and disease resistance. Consistent with these observations, siz1 plants exhibited enhanced resistance to Pst DC3000 expressing avrRps4 , a bacterial avirulence determinant that responds to the EDS1/PAD4 ‐dependent TIR‐NBS‐type R gene. In contrast, siz1 plants were not resistant to Pst DC3000 expressing avrRpm1 , a bacterial avirulence determinant that responds to the NDR1‐dependent CC‐NBS‐type R gene. Jasmonic acid (JA)‐induced PDF1.2 expression and susceptibility to Botrytis cinerea were unaltered in siz1 plants. Taken together, these results demonstrate that SIZ1 is required for SA and PAD4‐mediated R gene signalling, which in turn confers innate immunity in Arabidopsis.