The ABC transporter BcatrB from Botrytis cinerea exports camalexin and is a virulence factor on Arabidopsis thaliana.
Arabidopsis thaliana is known to produce the phytoalexin camalexin in response to abiotic and biotic stress. Here we studied the mechanisms of tolerance to camalexin in the fungus Botrytis cinerea, a necrotrophic pathogen of A. thaliana. Exposure of B. cinerea to camalexin induces expression of BcatrB, an ABC transporter that functions in the efflux of fungitoxic compounds. B. cinerea inoculated on wild-type A. thaliana plants yields smaller lesions than on camalexin-deficient A. thaliana mutants. A B. cinerea strain lacking functional BcatrB is more sensitive to camalexin in vitro and less virulent on wild-type plants, but is still fully virulent on camalexin-deficient mutants. Pre-treatment of A. thaliana with UV-C leads to increased camalexin accumulation and substantial resistance to B. cinerea. UV-C-induced resistance was not seen in the camalexin-deficient mutants cyp79B2/B3, cyp71A13, pad3 or pad2, and was strongly reduced in ups1. Here we demonstrate that an ABC transporter is a virulence factor that increases tolerance of the pathogen towards a phytoalexin, and the complete restoration of virulence on host plants lacking this phytoalexin.
Stefanato
Francesca L
FL
Department of Biology, University of Fribourg, Chemin du Musée 8, CH-1700 Fribourg, Switzerland.
Abou-Mansour
Eliane
E
Buchala
Antony
A
Kretschmer
Matthias
M
Mosbach
Andreas
A
Hahn
Matthias
M
Bochet
Christian G
CG
Métraux
Jean-Pierre
JP
Schoonbeek
Henk-jan
HJ
D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000382:microbiology* / Q000528:radiation effects; D020171:Botrytis / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D007211:Indoles / Q000378:metabolism*; D009154:Mutation; D010935:Plant Diseases / Q000382:microbiology; D012331:RNA, Fungal / Q000378:metabolism; D018749:RNA, Plant / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism*; D014466:Ultraviolet Rays; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*; D000094162:Phytoalexins
D018528:ATP-Binding Cassette Transporters; D005656:Fungal Proteins; D007211:Indoles; D012331:RNA, Fungal; D018749:RNA, Plant; D013844:Thiazoles; D037521:Virulence Factors; C437164:ABC transporter BcatrB; C102405:camalexin; D000094162:Phytoalexins