Understanding the Role of SRO Genes in Rapeseed’s Response to Drought Stress

The study identified 19 BnaSROs from the rapeseed genome and analyzed their sequence characteristics, phylogenetic relationships, gene structures, and conserved domains. Additionally, the researchers explored the collinearity relationships of the SRO members in Brassica napus and Brassica juncea. Collinearity refers to the conservation of gene order on chromosomes, which can help in understanding the evolutionary relationships between genes.

The expression profiles of these BnaSROs were examined under various stress conditions, including ABA (abscisic acid), MeJA (methyl jasmonate), and water-deficit drought treatments using quantitative PCR (qPCR). The results indicated that BnaSROs exhibit multiple stress-responsive expression patterns. Specifically, BnaSRO1 and BnaSRO11 were identified as major drought-regulated members, likely functioning through interactions with NAC transcription factors. Transcription factors are proteins that help turn specific genes on or off by binding to nearby DNA.

This study builds on earlier research that has explored the genetic basis of rapeseed’s adaptation and agronomic traits. For instance, a comprehensive genomic assessment of rapeseed identified 628 associated loci-related causative candidate genes for 56 agronomically important traits^[2]. This earlier study highlighted the importance of understanding the genetic basis for improving rapeseed varieties, providing a valuable genomic resource for genome-assisted breeding. The current study on SROs complements this by focusing on the role of these genes in drought stress responses.

Additionally, the study on the miR169-NF-YA8 regulatory module in rapeseed demonstrated that miR169n acts as a negative regulator of drought resistance by targeting the NF-YA8 gene^[3]. Overexpression of NF-YA8 led to improved drought tolerance, suggesting that targeting specific genes can enhance stress resistance. The current study on SROs adds another layer to this understanding by identifying specific SRO genes that respond to drought stress.

The SROs are a highly conserved family of plant-specific proteins with crucial functions in stress adaptation and development^[4]. They contain domains such as the poly(ADP-ribose) polymerase (PARP) domain and the RST (RCD-SRO-TAF4) domain, which are involved in protein interactions and possibly transcription factor regulation. Despite the presence of the PARP domain, SROs do not possess ADP-ribosyl transferase activity, suggesting that their function might be related to transcription factor regulation and complex formation.

The current study’s findings provide a solid foundation for further functional analysis of the SRO gene family in rapeseed. By understanding the specific roles of BnaSRO1 and BnaSRO11 in drought stress responses, researchers can develop strategies to enhance drought resistance in rapeseed. This could involve genetic modifications or selective breeding to promote the expression of these key genes under drought conditions.

In conclusion, the study by the Guizhou Academy of Agricultural Sciences offers valuable insights into the role of the SRO gene family in rapeseed’s response to drought stress. By identifying and characterizing key SRO genes, this research paves the way for developing drought-resistant rapeseed varieties, thereby improving yield and expanding the crop’s cultivation areas.