Identification of OSCA gene family in Solanum habrochaites and its function analysis under stress

OSCA (hyperosmolality-gated calcium-permeable channel) is a calcium permeable cation channel protein that plays an important role in regulating plant signal transduction. It is involved in sensing changes in extracellular osmotic potential and an increase in Ca.sup.2+ concentration. S. habrochaites is a good genetic material for crop improvement against cold, late blight, planthopper and other diseases. Till date, there is no report on OSCA in S. habrochaites. Thus, in this study, we performed a genome-wide screen to identify OSCA genes in S. habrochaites and characterized their responses to biotic and abiotic stresses. A total of 11 ShOSCA genes distributed on 8 chromosomes were identified. Subcellular localization analysis showed that all members of ShOSCA localized on the plasma membrane and contained multiple stress-related cis acting elements. We observed that genome-wide duplication (WGD) occurred in the genetic evolution of ShOSCA5 (Solhab04g250600) and ShOSCA11 (Solhab12g051500). In addition, repeat events play an important role in the expansion of OSCA gene family. OSCA gene family of S. habrochaites used the time lines of expression studies by qRT-PCR, do indicate OSCAs responded to biotic stress (Botrytis cinerea) and abiotic stress (drought, low temperature and abscisic acid (ABA)). Among them, the expression of ShOSCAs changed significantly under four stresses. The resistance of silencing ShOSCA3 plants to the four stresses was reduced. This study identified the OSCA gene family of S. habrochaites for the first time and analyzed ShOSCA3 has stronger resistance to low temperature, ABA and Botrytis cinerea stress. This study provides a theoretical basis for clarifying the biological function of OSCA, and lays a foundation for tomato crop improvement.