ABSTRACT
Calmodulin-binding transcription activators (CAMTAs) are a family of transcription factors that play an important role in plants’ response to the various biotic and abiotic stresses. The common bean (Phaseolus vulgaris L.) is one of the most important crops in the world and plays a pivotal role in sustainable agriculture. To date, the composition of CAMTA genes in genomes of Phaseolus species and their role in resistance to drought stress are not known. In this study, five PhavuCAMTA genes were characterized in common bean genome through bioinformatics analysis, the morphological and biochemical response of 23 Ph.vulgaris genotypes to different levels of drought stress were evaluated and the expression patterns of PhCAMTA1 in the leaf tissues of sensitive and tolerant genotypes were analysed. Gene structure, protein domain organization and phylogenetic analyses showed that the CAMTAs of Phaseolus were structurally similar and clustered into three groups as other plant CAMTAs. Genotypes showeda differential response to drought stress. Thus, the plant height, number of nodes and flower, total chlorophyll and total protein content, and activity of antioxidant enzymes (ascorbate peroxidase and catalase) in plants significantly influenced by genotype and drought stress interaction. Moreover, the resistant and susceptible genotypes were identified according to three-dimensional plots and the expression patterns of PhavuCAMTA1 gene were studied using real-time quantitative polymerase chain reaction. The results of the present study serve as the basis for future functional studies on the Phaseolus CAMTA family.