Plant Regeneration and Agrobacterium-Mediated Gene Transfer Studies in Leaf Tissue of male Himalayan Poplar (Populus ciliata Wall.)

Abstract

A system was developed to obtain high frequency plant regeneration, genetic transformation and expression of foreign gene in leaf tissue of Himalayan poplar. High frequency shoot regeneration via direct organogenesis was obtained on MS medium supplemented with 0.5 mg l-1 Kn and 0.2 mg l-1 IAA. High frequency root induction from in vitro shoots was obtained on the MS medium supplemented with 0.1 mg l-1 IAA. Plantlets were regenerated within two months. Agrobacterium – mediated gene transfer studies were carried out using binary vector (pBI 121) using npt-II and gus genes. After co-cultivation, transformed calli were selected on the selective medium containing 50 mg l-1 kanamycin. Most of the calli obtained from leaf explants on the selective medium were GUS positive expressing ß-glucuronidase enzyme activity. These results demonstrate the transformation of Himalayan poplar cells derived from mature plants and the potential for using Agrobacterium tumefaciens to transfer economically important genes to Himalayan poplar. To our knowledge this is the first report on the direct organogenesis and genetic transformation in leaf tissue of male plant of Populus ciliata.