Isolation and Expression Analysis of Cold Acclimation Specific Gene CAS15# From White Clover(Trifolium repens L)

Isolation and Expression Analysis of Cold Acclimation Specific Gene CAS15# From White Clover(Trifolium repens L

Cold stress severely limits crop production in temperate regions by affecting growth and developments of plants. At molecular level cold-regulated genes are known to play an important role in conferring cold tolerance in plants. In this study, for the first time we have cloned a cold acclimation specific (CAS) gene TRICAS15, from the cold tolerant ecotype of white clover using degenerate gene specific primers. TRICAS15 ORF was 474bp long and encoded for 16.3kD protein which contained 15 amino acid long motifs present in tandem. It showed homology with the CAS15 genes of different species of leguminosae. Phylogeny analysis revealed that CAS genes found in different species of leguminosae might have evolved from a basic gene and diverged during course of evolution. Expression of TRICAS15 fluctuated during the course of cold treatment and appeared to be specific to cold. Further, at the structural level TRICAS15 polypeptide was similar to dehydrins and might be performing similar functions during cold stres.