The expression of alfalfa MsPP2CA1 gene confers ABA sensitivity and abiotic stress tolerance on Arabidopsis thaliana.

Although clade A phosphatase 2Cs (PP2CAs) are well known to regulate abscisic acid (ABA) signaling, few members of this family have been identified in alfalfa so far. Here, the isolation and characterization of the gene MsPP2CA1 from alfalfa is described. Its transcription was found to be highly inducible by treatment with abscisic acid, salt, hydrogen peroxide and polyethylene glycol. The constitutive expression of MsPP2CA1 in Arabidopsis thaliana seedlings mitigates root growth imposed by either salinity or oxidative stress, while also raising the level of sensitivity to ABA during germination and early seedling development, and promoting stomatal closure. In transgenic plants, many ABA-dependent stress-responsive genes were activated, and the expressions of catalase and peroxidase which involved in reactive oxygen scavenging were promoted. MsPP2CA1 is suggested as a candidate for the genetic manipulation of salinity tolerance in legume species.