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Susceptibility to Verticillium longisporum is linked to monoterpene production by TPS 23/27 in Arabidopsis
Author(s) -
Roos Jonas,
Bejai Sarosh,
Mozūraitis Raimondas,
Dixelius Christina
Publication year - 2015
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/tpj.12752
Subject(s) - monoterpene , jasmonic acid , biology , methyl jasmonate , botrytis cinerea , arabidopsis , verticillium , botany , verticillium dahliae , pathogenic fungus , leptosphaeria maculans , botrytis , mutant , gene , fungus , biochemistry
Summary The fungus Verticillium longisporum is a soil‐borne plant pathogen of increasing economic importance, and information on plant responses to it is limited. To identify the genes and components involved in the early stages of infection, transcripts in roots of V. longisporum ‐challenged Arabidopsis Col‐0 and the susceptible NON ‐ RACE SPECIFIC DISEASE RESISTANCE 1 ( ndr1‐1 ) mutant were compared using ATH 1 gene chips. The analysis revealed altered transcript levels of several terpene biosynthesis genes, including the monoterpene synthase TPS 23/27 . When transgenic 35S: TPS 23/27 and TPS 23/27‐ami RNA plants were monitored the over‐expresser line showed enhanced fungal colonization whereas the silenced genotype was indistinguishable from Col‐0. Transcript analysis of terpene biosynthesis genes suggested that only the TPS 23/27 pathway is affected in the two transgenic genotypes. To confirm changes in monoterpene production, emitted volatiles were determined using solid‐phase microextraction and gas chromatography–mass spectrometry. Levels of all identified TPS23/27 monoterpene products were significantly altered in the transgenic plants. A stimulatory effect on conidial germination and hyphal growth of V. longisporum was also seen in co‐cultivation with 35S: TPS 23/27 plants and upon exposure to 1,8‐cineole, the main product of TPS 23/27. Methyl jasmonate treatments of myc2‐1 and myc2‐2 mutants and analysis of TPS 23/27:uidA in the myc2‐2 background suggested a dependence on jasmonic acid mediated by the transcription factor MYC 2. Taken together, our results show that TPS 23/27‐produced monoterpenes stimulate germination and subsequent invasion of V. longisporum in Arabidopsis roots.