Genome-wide identification and expression analysis of the response regulator gene family in alfalfa ( L.) reveals their multifarious roles in stress response.

As important components of the two-component regulatory system, response regulatory proteins (RRPs) play a crucial role in histidine phosphorylation-mediated signal transduction in response to environmental fluctuations. Accumulating evidence has revealed that RRPs play important roles in plant growth and stress response. However, the specific functions of genes () in cultivated alfalfa remain ambiguous. Therefore, in this study, we identified and characterized the family genes in the alfalfa genome using bioinformatics methods. Our analysis revealed 37 in the alfalfa genome of Zhongmu No.1 that were unevenly distributed on the chromosomes. Cis-elements analysis revealed the involvement of in responses to light, stress, and various plant hormones. Expression analysis of in different tissues revealed their distinct tissue expression patterns. These findings provide preliminary insights into the roles of in plant responses to abiotic stress, which can be used to improve the stress tolerance of autotetraploid-cultivated alfalfa plants genetic engineering.