Overexpression of ICE1 gene in mungbean (Vigna radiata L.) for cold tolerance

The putative transgenic mungbean (Vigna radiata Var. OBGG-52) plants were regenerated on Murashige and Skoog (1962) medium supplemented with 1.0 mg/L 6-benzylaminopurine (BA). The transgenic status of transformants (T2 generation) was determined through PCR analysis using nptII and ICE1 gene-specific primers as well as uidA reporter gene expression. About 75% of the transformed plantlets were successfully established in the greenhouse. Overexpression of ICE1 gene in transgenic mungbean plants resulted in cold-tolerance at the seedling stage when compared to non-transformed plants. Seeds from T2 generation were further studied for cold tolerance through nutrient culture. Transgenic seeds had significantly increased germination and growth on a nutrient medium at 10–14 °C in growth chamber compared to the non-transgenic control. Moreover, the root and shoot length of transformed plants were significantly increased at 10–14 °C as compared with the non-transformed plants. Under cold stress, it was also observed that the transformed plantlets have significantly higher chlorophyll, proline, and lipid content as well as anti oxidative enzyme activity as compared to non-transformed plants. This study will help in mungbean improvement program for abiotic stress tolerance.