Effect of ochratoxin A-producing Aspergilli on stilbenic phytoalexin synthesis in grapes.
Berries of Vitis vinifera L. cv. Barbera were infected, at veraison and during ripening, by a conidial suspension of A. japonicus, A. ochraceus, A. fumigatus and two isolates of A. carbonarius to control ochratoxin A production and stilbene induced synthesis. The experimental design provided also for intact and punctured berries and incubation temperature of 25 degrees C and 30 degrees C. All the tested fungi, except A. fumigatus, significantly increased trans-resveratrol synthesis over the control, while trans-piceid was not affected; only A. ochraceus significantly elicited the berries to synthesize piceatannol. The two isolates of A. carbonarius produced higher amounts of ochratoxin A than did the other fungi. A positive correlation between ochratoxin A and trans-resveratrol synthesis occurred. trans-Resveratrol and piceatannol showed fungicidal activity against A. carbonarius, being able to completely inhibit fungal growth at a concentration of 300 microg/g and 20 microg/g, respectively.
D001230:Aspergillus / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D005638:Fruit / Q000378:metabolism / Q000382:microbiology*; D007700:Kinetics; D009793:Ochratoxins / Q000096:biosynthesis*; D010936:Plant Extracts / Q000096:biosynthesis*; D000077185:Resveratrol; D012717:Sesquiterpenes; D013267:Stilbenes / Q000378:metabolism* / Q000494:pharmacology; D013729:Terpenes; D027843:Vitis / Q000378:metabolism / Q000382:microbiology*; D000094162:Phytoalexins
D009793:Ochratoxins; D010936:Plant Extracts; D012717:Sesquiterpenes; D013267:Stilbenes; D013729:Terpenes; C025589:ochratoxin A; C041525:3,3',4,5'-tetrahydroxystilbene; D000077185:Resveratrol; D000094162:Phytoalexins