Agrobacterium mediated transformation of ABA biosynthetic pathway coding genes for enhanced drought tolerance in Nicotiana tabacum

Abstract

Abscisic acid (ABA) is an important hormone that regulates stomata closure, developmental stages and drought tolerance in plants. NCED (EC 1.13.11.51) is a key enzyme involved in the biosynthesis of abscisic acid. Transgenic tobacco plants with the integration of nced and rpk genes under the control of stress inducible promoters viz., sal T and lea P were developed through Agrobacterium mediated transformation. Over expression of integrated genes were confirmed by leaf disc assay method by imposing artificial stress using methyl Viologen (5 μMmethyl Viologen for 36 hrs).On exposure of stress, transgenic plants showed high content of chlorophyll pigments and low level of electrolyte leakage and MDA were observed than the wild type plants. Over expression of nced and rpk enhanced the abscisic acid content and increased the tolerance to drought stress.