Genome-wide identification of SIMILAR to RCD ONE (SRO) gene family in rapeseed ( L.) reveals their role in drought stress response.

Rapeseed ( L.) is an important oilseed crop widely cultivated worldwide, and drought is the main environmental factor limiting its yield enhancement and the expansion of planted areas. SIMILAR TO RCD ONE () is a plant-specific small gene family that plays a crucial role in plant growth, development, and responses to abiotic stresses such as drought. However, the functional role of in rapeseed remains poorly understood. In this study, 19 were identified from the rapeseed genome, with 9, 10, 10, 18, and 20 members identified from the genomes of , , , , and , respectively. We then analyzed their sequence characteristics, phylogenetic relationships, gene structures, and conserved domains, and explored the collinearity relationships of the members in and . Next, we focused on the analysis of tissue expression and stress-responsive expression patterns of rapeseed members and examined their expression profiles under ABA, MeJA and water-deficit drought treatments using qPCR. Transcriptome data analysis and qPCR detection indicated that exhibit multiple stress-responsive expression patterns. and , which are likely to function through interactions with NAC transcription factors, were screened as major drought-regulated members. Our results provide a solid foundation for functional analysis of the role of the gene family in abiotic stress responses, especially drought stress responses, in rapeseed.