Identification and characterization of the CONSTANS-like gene family and its expression profiling under salt treatment in alfalfa (Medicago sativa L.)

Abstract

Alfalfa (Medicago sativa L.) is a globally cultivated, high-quality forage crop. The CONSTANS-LIKE (COL) genes play crucial roles in regulating flowering time and stress responses in plants. However, the functional characterization of COL genes in alfalfa remain largely unexplored. In this study, we conducted a genome-wide analysis of the Xinjiang Daye alfalfa genome and identified 36 MsCOL genes. Multiple sequence alignment confirmed that all MsCOL genes contain conserved B-box and CCT (CO, CO-like and TOC1) domains. Phylogenetic analysis and gene structure analyses classified the MsCOL genes into two subclades, exhibiting similar exon-intron organization and conserved motif distributions. Chromosomal mapping revealed that these genes are distributed across 22 chromosomes. Expression profiling under salt stress demonstrated that MsCOL genes exhibit expression patterns, indicating their potential involvement in abiotic stress responses. These findings enhance our understanding of MsCOL gene function in alfalfa and provide a theoretical basis for breeding salt-tolerant alfalfa cultivars.