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Arabidopsis thaliana plants differentially modulate auxin biosynthesis and transport during defense responses to the necrotrophic pathogen Alternaria brassicicola
Author(s) -
Qi Linlin,
Yan Jiao,
Li Yanan,
Jiang Hongling,
Sun Jiaqiang,
Chen Qian,
Li Haoxuan,
Chu Jinfang,
Yan Cunyu,
Sun Xiaohong,
Yu Yuanjie,
Li Changbao,
Li Chuanyou
Publication year - 2012
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2012.04208.x
Subject(s) - alternaria brassicicola , auxin , biology , arabidopsis thaliana , arabidopsis , plant defense against herbivory , microbiology and biotechnology , jasmonic acid , botany , mutant , gene , genetics
Summary• Although the role of auxin in biotrophic pathogenesis has been extensively studied, relatively little is known about its role in plant resistance to necrotrophs. • Arabidopsis thaliana mutants defective in different aspects of the auxin pathway are generally more susceptible than wild‐type plants to the necrotrophic pathogen Alternaria brassicicola . We show that A. brassicicola infection up‐regulates auxin biosynthesis and down‐regulates the auxin transport capacities of infected plants, these effects being partially dependent on JA signaling. We also show that these effects of A. brassicicola infection together lead to an enhanced auxin response in host plants. • Application of IAA and MeJA together synergistically induces the expression of defense marker genes PDF1.2 (PLANT DEFENSIN 1.2) and HEL (HEVEIN‐LIKE), suggesting that enhancement of JA‐dependent defense signaling may be part of the auxin‐mediated defense mechanism involved in resistance to necrotrophic pathogens. • Our results provide molecular evidence supporting the hypothesis that JA and auxin interact positively in regulating plant resistance to necrotrophic pathogens and that activation of auxin signaling by JA may contribute to plant resistance to necrotrophic pathogens.