Gourab Ghosh
St. Xavier’s College, India
Title: Novel technique to develop transgenic selectable marker free pigeonpea (Cajanus cajan) conferring resistance against pod borer Helicoverpa armigera
Biography
Biography: Gourab Ghosh
Abstract
Pigeonpea is one of the major grain legumes of tropics and subtropics, covering vast regions of developing countries from Africa, Asia to Latin America. It ranks fifth in area among pulses after soybean, common bean, peanut, and chickpea.Globally, pigeonpea is cultivated on 4.92 million hectares with an annual production of 3.65 metric tons and productivity of 898 kg/ha2.As they are grown in harsh environments and exposed to a variety of biotic and abiotic stresses, their productivity has not increased conspicuously for the last 50 years.Among many insect pests, the pod borer Helicoverpa armigera causes significant damage to this crop. It is the most devastating Lepidopteran pest and causes extensive economic losses to the tune of US$ 300 million annually. The present study seeks to protect pigeonpea plants from H. armigera infestation by incorporating cry1Ac and cry2Aa genes, through a unique and efficient gene transfer method. An Agrobacterium tumefaciens-mediated transformation strategy was implemented using in vitro transgenic shoot-grafting technique. A. tumefaciens harbouring different binary vectors containing cry1Ac and cry2Aa geneswere used for transgenic pigeonpea development. An overall 7-9% of transformation frequency was recorded. After monitoring transgene integration by Southern hybridization, transgenic T1 and T2 lines were further analyzed by western blot, ELISA and insect bioassay. Transgenic lines obtained,exhibited optimum expression of Cry1Ac and Cry2Aa proteins. This study was further extended to the development of selectable marker (nptII) free cry1Ac expressing transgenic lines using cre-lox mediated marker elimination system