Role of Plant Calmodulin Isoforms in Tolerance to Abiotic Stress

Calmodulin(CaM) and Ca2+ have been implicated in adaptation of plants to changes in its environment. Arabidopsis thaliana (Arabidopsis) genome has nine genetic loci encoding calmodulin protein isoforms. We have used wild type (WT) and T-DNA insertion mutants of seven calmodulin genes in Arabidopsis to determine role of specific isoform of calmodulin in abiotic stress in Arabidopsis.The obtained results suggest that collective amounts of CaM proteins may regulate GAD activity in response to abiotic stress rather than specific CaM protein under different stress conditions. Steady-state level of CAM mRNA in WT and cam mutants provides support for some level of compensation in expression CAM genes in Arabidopsis thaliana.