Phaseolus vulgaris genome possesses CAMTA genes, and phavuCAMTA1 contributes to the drought tolerance

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.

Efficient In Vitro Somatic Embryogenesis and Plant Regeneration from Mature and Immature Embryos of Wheat ( Triticum aestivum L.)

ABSTRACT An efficient regeneration system is a pre-requisite for the application of genetic transformation and functional genomics study of important plants. In this study, the effect of different factors (plant growth regulators, casein hydrolysate, aspartic acid and ascorbic acid) on in vitro embryogenesis and regeneration of Arta, Bahar and Zagros cultivars from mature and immature explants were investigated. Immature and mature embryos were dissected from disinfected seeds 20-25 days after pollination and imbedded mature seeds, respectively, and cultured on MS (Murashige and Skoog) medium supplemented with different compounds. The results showed that immature embryos expose high capacity of embryogenesis and regeneration in comparison with mature embryos. There were significant differences between cultivars in terms of the percentage of callus induction and regeneration. Plant growth regulators had significant effect on percentage of callus induction in mature explants and percentage of regeneration from both explants. In immature explants, the highest percentage of regeneration (65%) was achieved with the Arta cultivar calli derived from MS medium supplemented with 1mg/L 2,4-D, 2 mg/L Picloram and 200 mg/L casein hydrolysate, and subcultured on MS medium. Also, the highest percentage of regeneration (52.38%) from mature embryo explants was achieved in the Arta cultivar with callus induction on MS medium supplemented with 1 mg/L 2,4-D, 2 mg/L Picloram and 200 mg/L casein hydrolysate and regeneration on MS medium containing 0.05 mg/L NAA.