Activities and Gene Expressions of Phenylpropane Metabolic Enzymes in Populus simonii×P. nigra by Herbivore Induction of Lymantria dispar(Lepidoptera:Lymantriidae)

【Objective】Phenylalanine is a precursor of many plant compounds that are essential for plant reproduction,growth,development,and defense against different types of stress.Phenylalanine biosynthesis pathway is one of the most important secondary metabolic pathways in plants.In the phenylalanine biosynthesis pathway,the cinnamate 4-hydroxylase(C4H) and 4-coumarate CoA ligase(4CL) are involved in the core reaction of phenylpropane metabolism.Lymantria dispar is a major forest pest in the world.In this study,our objective is to explore the effects of Lymantria dispar herbivore on key enzymes in phenylalanine biosynthesis pathway of Populus simonii × P.nigra for inducing defense,and to provide genetic materials for promoting host resistance by genetic engineering method.【Method】The full length of C4H and 4CL was cloned by RT-PCR technology and its characteristics were analyzed in this study.The phylogenetic trees of C4H and4CL were constructed by Neighbor-joining method,respectively.The activities of C4H and 4CL w