Ectopic Expression of a Novel Cold-resistance Protein 1 (BoCRP1) from Brassica Oleracea Promotes Tolerance to Cold via Modulating Stress Associated Components

Abstract

Cold stress is considered as a major environmental factor that adversely affect the plant growth and distribution. Therefore, there arises an immediate need to cultivate effective strategies aimed at developing stress-tolerant crops that would boost the production and minimise the risks associated with cold stress. In this study, a novel cold-responsive protein1 isolated from Brassica oleracea (BoCRP1) was ectopically expressed in a cold susceptible tomato genotype Shalimar 1 and its function was investigated in response to chilling stress. BoCRP1 was constitutively expressed in all the tissues of B. oleracea including leaf, root and stem however, its expression was found to be significantly increased in response to cold stress. Moreover, transgenic tomato plants expressing BoCRP1 exhibited increased tolerance to chilling stress (4oC) with an overall improved rate of seed germination, increased root length, reduced membrane damage and increase in accumulation of osmoprotectants. Furthermore, we observed increased transcript levels of stress responsive genes and enhanced accumulation of ROS scavenging enzymes in transgenic on exposure to chilling stress. These results are therefore strongly in support of the role of BoCRP1 in offering the plant a protective shield and heightened resilience to chilling stress by maintaining osmotic balance, utilising the cellular antioxidant system and enhancing the transcription of cold responsive genes.