T. Shiraishi, N. Hori, Tetsuji Yamada
Apr 25, 1990
Citations
0
Influential Citations
11
Citations
Journal
Japanese Journal of Phytopathology
Abstract
Phytoalexins (PAs) are believed to play important roles in defense mechanisms of plant against the attack by phytopathogenic microorganisms. It was recently demonstrated that the production of pisatin, a major PA of pea plant, was regulated at the level of gene expression of two key-enzymes in flavonoid synthetic pathway, phenylalanine ammonia-lyase and chalcone synthase when the tissues were treated with elicitor and/or suppressor from Mycosphaerella pinodes1). It is, however, not clear how the elicitor is recognized by pea cells, and what is the second messenger in the process of signal transduction for the defense reaction. In carrot suspension-cultured cells, Ca2+ and cAMP seem to play as the second messengers for the production of 6-methoxymellein, a PA of carrot2). The increase of Ca2+ in soybean cultured cells was believed to enhance the enzyme activities in glyceollin biosynthetic pathway and its accumulation3). However, it was reported that fluctuation of Ca2+ content did not correlate to the chitosanor Fusarium solani-induced pisatin production in pea pod tissue4). In this paper, we report the effect of some putative inhibitors of signal transduction on pisatin accumulation and discuss the regulatory mechanisms in the early process of pisatin production in pea epicotyls.