DEFENSIVE RESPONSES OF POPLUS DELTOIDES 895 SEEDLINGS AGAINST EXOGENOUS METHYL JASMONATE

Abstract

Methyl jasmonate (MeJA) is a chemical elicitor that induces a series of defensive responses in plants and has been widely used to simulate pathogens and herbivore attacks for several decades. This study aimed to determine the effect of exogenous MeJA on one-year-old Populus deltoids 895 seedlings. MeJA solution (10µM) was sprayed on the leaves, and the activities of sugar, free amino acid, four defensive enzymes, tannin, flavone, phenolic acid and volatile compounds were examined at different time periods. Sugar, free amino acid, and protein contents decreased to some extent regardless of the type of treatment (direct MeJA-treated leaves or indirect contralateral non-MeJA-treated leaves), whereas tannin, flavone, and phenolic acid increased. PPO, LOX, TI, and CI were activated by the treatment. MeJA also affected emissions of the leaf volatiles. These results indicate that MeJA could generate or trigger defensive responses by P. deltoids seedlings. This study provided basic information as reference for further studies on defoliators performance after feeding on MeJA-treated poplar leaves.