Effects of exogenous jasmonates induced systemic acquired resistance on the content of phenolic acid in Korean pine

Dioryctria abietella and D. sylvestrella are close relative species, both of which damage the cones concomitantly on Pinus koraiensis. In this study, we investigated the phenolic acid content in the main tips and cones of Korean pine treated by jasmonates sprayed, to explore induce defense of pine. We collected healthy, larvae fed, and jasmonates sprayed tips and cones, to determine phenolic acid content by high performance liquid chromatography (HPLC).The results showed that 5 kinds of phenolic acid, including coumaric acid, phenylacetic acid, ferulic acid, salicylic acid and cinnamic acid were detected in healthy cones. Meanwhile, 5 number but different kinds of phenolic acid in healthy main tips were determined, including coumaric acid, phenylacetic acid, benzoic acid, salicylic acid and cinnamic acid. After larvae fed, protocatechuic acid and carbolic acid in cones, and carbolic acid, ferulic acid in tips were detected, and many kinds of phenolic acid(chlorogenic acid, caffeic acid, syringic acid, phenylaetic acid, ferulic acid, benzoic acid, salicylic acid, cinnamic acid)were significantly increased in cones and main tips, whereas coumaric acid decreased in cone compared with healthy plant. Exogenous cis-jasmone induced more kinds of phenolic acid, such as carbolic acid in cones, and syringic acid in both cones and main tips compared with methyl-jasmonate treatments. In addtion, protocatechuic acid, chlorogenic acid, syringic acid, phenolic acids in cones and tips treated by exogenous cis-jasmone were higher than that of herbivore-induced, while the content and induction time of other kinds of phenolic acid by cis-jasmone and herbivore induced were more similar. 10 mmol/L exogenous cis-jasmone point or systematic atomizing sprayed induced phenolic acids were already significantly higher or similar with herbivore-induced. So 10 mmol/L is the effective dose enhancing the resistance of host pine against shoot borer larvae feeding.