Cloning, expression and wounding induction of -caryophyllene synthase gene from Mikania micrantha H.B.K. and allelopathic potential of -caryophyllene

�-Caryophyllene is an important volatile sesquiterpene of plants that may serve as allelochemical to influence the neighboring plant growth or as an indirect defence to attract natural herbivore enemies. A partial cDNA for �-caryophyllene synthase gene was isolated from the expressed sequence tag (EST) library of Mikania micrantha leaves. The full length cDNA of �-caryophyllene synthase from M. micrantha , designated as MmCS was obtained by rapid amplification of cDNA ends (RACE) methods. This MmCS cDNA is 1898 bp in full length and it encodes a putative protein of 547 amino acids. MmCS expression was significantly increased in M. micrantha leaves within 3-days after wounding during a 5-day interval following mechanical wounding. Bioassay showed that �-caryophyllene at � 3 mg L -1 significantly inhibited the germination rates and seedling growth of Brassica campestris and Raphanus sativus . These results suggest that �-caryophyllene synthase and �-caryophyllene may play an important role in allelopathy for successful invasion of M. micrantha .