RESEARCH ARTICLE Open Access Genome-wide survey and expression analysis of the OSCA gene family in rice

Background: Reception of and response to exogenous and endogenous osmotic changes is important to sustain plant growth and development, as well as reproductive formation. Hyperosmolality-gated calcium-permeable channels (OSCA) were first characterised as an osmosensor in Arabidopsis and are involved in the perception of extracellular changes to trigger hyperosmolality-induced [Ca2+]i increases (OICI). To explore the potential biological functions of OSCAs in rice, we performed a bioinformatics and expression analysis of the OsOSCA gene family. Results: A total of 11 OsOSCA genes were identified from the genome database of Oryza sativa L. Japonica. Based on their sequence composition and phylogenetic relationship, the OsOSCA family was classified into four clades. Gene and protein structure analysis indicated that the 11 OsOSCAs shared similar structures with their homologs in Oryza sativa L. ssp. Indica, Oryza glaberrima, and Oryza brachyantha. Multiple sequence alignment analysis revealed a conserved DUF221 domain in these members, in which the first three TMs were conserved, while the others were not. The expression profiles of OsOSCA genes were analysed at different stages of vegetative growth, reproductive development, and under osmotic-associated abiotic stresses. We found that four and six OsOSCA genes showed a clear correlation between the expression profile and osmotic changes during caryopsis development and seed imbibition, respectively. Orchestrated transcription of three OsOSCAs was strongly associated with the circadia