The CYP707A Gene Family in Strawberry (Fragaria x ananassa)

Abscisic acid (ABA) is a plant hormone that plays several roles in plant development. The de novo synthesis and the reversible inactivation of ABA have been largely described in the literature; however, the degradation of ABA, promoted by the enzymes Abscisic Acid 8'-Hydroxylase, encoded by the CYP707A gene family, is still poorly elucidated. Strawberry (Fragaria x ananassa) has been used as a model to study the ABA-dependent maturation process of non-climacteric fruits, and the ABA-dependent response to abiotic stress. However, the CYP707A genes from this species have not been fully described and characterized. In this perspective, FaCYP707A sequences were identified from strawberry fruit transcriptome and several structural and comparative genomic analyzes were performed. Moreover, the expression of the FaCYP707A sequences identified was investigated in fruits under salt stress and ABA application. Four putative FaCYP707A were identified and the structural analysis confirmed the identity of three of them. The phylogenetic analysis allowed to determine their homologous in other plant species and to predict their evolutionary history; and the expression profile of the FaCYP707As demonstrated that FaCYP707A3 seems to be involved in the response against salt stress in an ABA-dependent manner. Moreover, the interaction network analysis pointed out proteins involved in the ABA metabolism, heavy metal homeostasis and detoxification, and cell wall dissemble. This study characterized for the first time the CYP707A gene family in F. ananassa; this information will guide future studies in order to develop biofortified fruits and stress tolerant plants.