title: Ethylene: indicator but not inducer of phytoalexin synthesis in soybean.
abstract: Cell wall preparations (elicitors) from Phytophthora megasperma var. sojae increase C(2)H(4) formation, phenylalanine ammonia lyase activity, and glyceollin accumulation in soybean cotyledons within about 1.5, 3, and 6 hours after treatment, respectively. The immediate precursor of C(2)H(4), 1-aminocyclopropane-1-carboxylic acid, stimulates C(2)H(4) formation like the elicitor within 1.5 hours after administration, whereas phenylalanine ammonia lyase activity and glyceollin concentration remain unchanged. Aminoethoxyvinylglycine, a specific inhibitor of C(2)H(4) formation in higher plants, inhibits elicitor-induced C(2)H(4) formation by about 95% but has no effects on phenylalanine ammonia lyase or glyceollin accumulation. It was concluded that C(2)H(4) is a signal accompanying the specific recognition process which finally leads to the induction of phytoalexin formation, but it is not functioning as a link or messenger in the induction sequence of glyceollin accumulation.
authors: Institut für Botanik und Mikrobiologie, Technische Universität München, D-8000 München, Federal Republic of Germany.
authors: I
authors: I
authors: Paradies
authors: J R
authors: JR
authors: Konze
authors: E F
authors: EF
authors: Elstner