Gum in apricot (Prunus armeniaca L.) shoots induced by methyl jasmonate

Abstract

It has been well known that some fungal pathogens (Monilia laxa, M. fructigena, Cytospora cincta), larvae of Grapholita molesta and plant hormone - ethylene, induce gummosis in apricot shoots. Methyl jasmonate (JA-Me) was also found to induce gummosis in apricot shoots as well as biotic and abiotic factors mentioned above. In order to know the mode of action of JA-Me on gum induction and/or formation, chemical composition of polysaccharides (after hydrolysis) in gums of apricot shoots induced by JA-Me compared with those by ethephon and their mixture, and naturally occurring ones was studied, resulted in the succesful identification of monosaccharides, and the similarity of a composition consisting of xylose, arabinose and galactose at molar ratio 1:10:14, respectively. These results suggest that beside different inducers of gum in apricot the mechanism of polysaccharides biosynthesis of gums is the same or similar. The physiological role for JA-Me on gum induction and/or formation in apricot shoots, and other species are also discussed.