Abstract

Jasmonates (JAs) are plant signal compounds and can induce many biochemical responses. In the current study, the effects of three concentrations of exogenous JAs plus control on the free amino acid (FAA) contentsin needles of Larix olgensis Herry seedlings were investigated. Our results showed that the proportions of nineessential FAAs detected/identified in all treatments varied with concentrations of JAs. Total FAA contents in control needles fluctuated in an increasing-decreasing-increasing pattern within a 20-day period; however, a decreasing-increasing-decreasing pattern was observed in JAs-treated needles compared to their controls.They were significantly affected by the interactions of time, JAs type and JAs concentration. Furthermore,methyl jasmonate (MeJA) showed stronger treatment effect on total FAA contents than did cis-jasmone (cisJ)or jasmonic acid (JA). While total FAA contents were significantly influenced by 0.01 mM JA, 0.1 mM cisJ and 0.1 and 1 mM MeJA treatments compared to their corresponding controls. The results indicated that exogenous JAs might induce significant changes of the individual FAA ratios and total FAA contents in larch needles. This could be a potential factor influencing the preference and performance of pest insects that utilizeL. olgensis as a host.

Key words: Larix olgensis, jasmonic acid, methyl jasmonate, cis-jasmone, induce function.