Methyl Jasmonate Induces Gums and Stimulates Anthocyanin Accumulation in Peach Shoots

The effect of methyl jasmonate (JA-Me) on the induction of gum was studied in relation to the action of ethylene in peach (Prunus persica Batsch cv. Benishimizu) shoots. JA-Me applied at concentrations of 0.1–2.5% (w/w) in lanolin paste to current growing or older shoots substantially induced gums 3 days after treatment. The amount of gums exuded increased depending on the dose of JA-Me. Ethephon (2-chloroethyl- phosphonic acid) at 1 or 2% (w/w) in lanolin induced gum and strongly enhanced the promoting effect of JA-Me on gum formation. JA-Me also induced anthocyanin accumulation in current growing shoots, but ethephon did not. Anthocyanin accumulation in response to JA-Me at a concentration of 10 mg/liter or higher was observed also in the cut shoots of peach. Ethephon (100 mg/liter) substantially inhibited anthocyanin accumulation induced by JA-Me. These facts suggest that JA-Me plays an important role in gum formation as well as ethylene and in anthocyanin accumulation and that these processes are not necessarily accompanied by each other in peach shoots. Received January 26, 1998; accepted March 4, 1998