[Role of active forms of oxygen in the induction of phytoalexin synthesis in Allium cepa cells].

The results of studies on the role of plant superoxidesynthase signal system in elicitation of antimicrobial phytoalexin (PA) synthesis in cultured Allium cepa cells are presented. Exogenic application of O2- and H2O2 generators results in formation of PA--Tcibulins 1D and 2 [symbol: see text] in A. cepa cells. The mechanism of PA elicitation does not require peroxidase activity. However, the inhibition of one of the possible sources of the reactive oxygen, HADPH oxidase, suppresses elicitor-stimulated PA production. "Oxidative burst" modulation by different chemical compounds in A. cepa cells results in changes of PA synthesis elicitation. The results obtained suggest the tough correlation between "oxidative burst" and elicitation of defense responses, PA synthesis in particular.