Ectopic Expression of Cold Responsive Gene Enhances Cold Stress Tolerance in .

Low-temperature stress severely affects the growth, development, and geographical distribution of various crop plants, resulting in significant economic loss to producers. In a quest to identify cold-regulated genes, we constructed a cDNA suppression subtractive library from a high altitude adapted ecotype of . We cloned a cold-induced gene CIPK from the subtracted cDNA library which gave homology to CIPK15 gene. The predicted 3D structure of CIPK protein also showed homology with CIPK protein. Quantitative real-time PCR analysis in seedlings exposed to 6 h of cold stress shows a 3-fold increase in the expression of CIPK transcript. The expression of CIPK was also differentially regulated by ethylene, CaCl, ABA, and SA treatments. Ethylene and CaCl2 treatments up regulated CIPK expression, whereas ABA and SA treatments down regulated the CIPK expression. Transgenic plants overexpressing CIPK gene under constitutive promoter show an increased level of proline and cell membrane stability. Taken together, our results suggest that the CIPK contributes to the cold-response pathway in plants.