Molecular cloning, characterization and expression pattern analysis of a jasmonic acid responsive sesquiterpene synthase gene from Persicaria minor

Terpenoids represent an important class of plant secondary metabolites, serving as component of plant defense against various biotic and abiotic stresses. A large number of structurally diverse terpenoid compounds have been identified from Persicaria minor (P. minor), an aromatic plant native to Malaysia. However, number of studies focusing on the P. minor terpenoid metabolism, especially at the genetic level is still very scarce. In the present study, a cDNA sequence (KT192706) from the leaves of P. minor, encoding a sesquiterpene synthase (PmSS) gene was successfully cloned. The complete sequence of PmSS comprised of 1724 bp with a 1680 bp open reading frame, corresponding to a deduced protein of 559 amino acids. Under the normal conditions, PmSS gene was found to be differentially expressed in the organs of P. minor. Significantly higher expression level of PmSS was recorded in leaves and stems which are, respectively, about 98 folds and 49 folds higher than that in the roots. In addition, the present study has also shown that the expression of PmSS gene was responsive towards the exogenous application of jasmonic acid in all organs of the P. minor.