Overexpression of StDREB30 Gene Enhances Salt Stress Tolerance in Transgenic Potato

Abstract

Salt stress is a major limiting factor for the decline in crop yield and productivity, worldwide. Potato is the third largest crop in terms of human consumption as two-thirds of the world population consumes potato as a staple food. However, this crop faces severe challenges due to salinization of arable land. Dehydration responsive element binding (DREB) transcription factors are key players in regulating plant defence signalling in response to various stress factors; hence, these are promising candidates for molecular plant breeding techniques. The current study focuses on the characterization of StDREB30 under salt stress conditions in transgenic potatoes. The results showed that after 15 days of 100 mM and 200 mM salt stress treatments, the transgenic plants overexpressing StDREB30 (OE) showed enhanced tolerance towards different salt stress concentrations. Moreover, in contrast to non-transgenic (NT) controls, the overexpressive line showed better growth, higher fresh weight, and an increase in number of microtubers during the stress period. The non-transgenic controls showed stunted growth and low fresh weight and failed to produce microtubers. The antioxidant assay analysis revealed a significant increase in superoxide dismutase, catalase, and ascorbic peroxidase activity with a decrease in malondialdehyde activity. These biochemical analyses highly correlate with the expression profiling data that showed 52-fold, 15-fold and 24-fold highly significant expression in transgenic roots, shoots and leaves respectively. Thus, this data indicates the high potency of StDREB30 gene in conferring tolerance to salt stress in overexpressive transgenic potato.