Detoxification of the cruciferous phytoalexin brassinin in Sclerotinia sclerotiorum requires an inducible glucosyltransferase.
The phytoalexins, brassinin, 1-methoxybrassinin and cyclobrassinin, were metabolized by the stem rot fungus Sclerotinia sclerotiorum into their corresponding glucosyl derivatives displaying no detectable antifungal activity. Importantly, co-incubation of S. sclerotiorum with camalexins, various phytoalexin analogs, and brassinin indicated that a synthetic camalexin derivative could slow down substantially the rate of brassinin detoxification. Furthermore, inducible brassinin glucosyltransferase (BGT) activity was detected in crude cell-free extracts of S. sclerotiorum. BGT activity was induced by the phytoalexin camalexin, and the brassinin analogs methyl tryptamine dithiocarbamate and methyl 1-methyltryptamine dithiocarbamate. The overall results suggest that the fungus S. sclerotiorum in its continuous adaptation and co-evolution with brassinin producing plants, has acquired efficient glucosyltransferase(s) that can disarm some of the most active plant chemical defenses.
Pedras
M Soledade C
MS
Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, SK S7N 5C9, Canada. s.pedras@usask.ca
Ahiahonu
Pearson W K
PW
Hossain
Mohammad
M
D000935:Antifungal Agents / Q000378:metabolism* / Q000633:toxicity; D001203:Ascomycota / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D002457:Cell Extracts; D002851:Chromatography, High Pressure Liquid; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism*; D008658:Inactivation, Metabolic; D007211:Indoles / Q000378:metabolism* / Q000633:toxicity; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010936:Plant Extracts / Q000378:metabolism* / Q000633:toxicity; D012717:Sesquiterpenes; D013729:Terpenes; D013859:Thiocarbamates / Q000378:metabolism* / Q000633:toxicity; D000094162:Phytoalexins
D000935:Antifungal Agents; D002457:Cell Extracts; D007211:Indoles; D010936:Plant Extracts; D012717:Sesquiterpenes; D013729:Terpenes; D013859:Thiocarbamates; C089020:brassinin; D005964:Glucosyltransferases; D000094162:Phytoalexins