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The Arabidopsis csb3 mutant reveals a regulatory link between salicylic acid‐mediated disease resistance and the methyl‐erythritol 4‐phosphate pathway
Author(s) -
Gil Ma José,
Coego Alberto,
MauchMani Brigitte,
Jordá Lucia,
Vera Pablo
Publication year - 2005
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.2005.02517.x
Subject(s) - salicylic acid , arabidopsis , complementation , mutant , biology , arabidopsis thaliana , psychological repression , biochemistry , plant disease resistance , atp synthase , enzyme , biosynthesis , genetics , gene , gene expression
Summary We report on constitutive subtilisin3 ( csb3 ), an Arabidopsis mutant showing strikingly enhanced resistance to biotrophic pathogens. Epistasis analyses with pad4 , sid2 , eds5 , NahG , npr1 , dth9 and cpr1 mutants revealed that the enhanced resistance of csb3 plants requires intact salicylic acid (SA) synthesis and perception. CSB3 encodes a 1‐hydroxy‐2‐methyl‐2‐butenyl 4‐diphosphate synthase, the enzyme controlling the penultimate step of the biosynthesis of isopentenyl diphosphate via the 2‐C‐methyl‐ d ‐erythritol‐4‐phosphate (MEP) pathway in the chloroplast. CSB3 is expressed constitutively in healthy plants, and shows repression in response to bacterial infection. We also show the pharmacological complementation of the enhanced‐resistance phenotype of csb3 plants with fosmidomycin, an inhibitor of the MEP pathway, and propose that CSB3 represents a point of metabolic convergence modulating the magnitude of SA‐mediated disease resistance to biotrophic pathogens.