Evolutionary Patterns and Functional Analysis of MATH Genes: Insights into Cold Tolerance Mechanisms in Oilseed Rape (Brassica napus).

MATH domain-containing proteins are important for plant growth, development, and stress adaptation, but their evolution and cold resistance in Brassica napus remain unexplored. Here, we characterized MATH genes in B. napus, Brassica rapa, Brassica oleracea, and Arabidopsis thaliana. We identified 461 MATH genes. Microcollinearity and pan-genomic analyses revealed stable syntenic gene numbers, purifying selection, and conserved evolution. The MATH family experienced ancient duplications, showing weak codon bias and reduced functional redundancy. Type A and D MATH genes exhibited low expression in root and leaf tissues, whereas type B and C genes showed high expression. RT-qPCR confirmed their roles in the cold stress response. Duplicated genes underwent defunctionalization or subfunctionalization. Subcellular localization showed that BnaA04g13830D and BnaC09g03690D were localized to the plasma membrane. Overexpression of BnaA04g13830D and BnaC09g03690D in Arabidopsis enhanced cold tolerance, potentially by influencing C-repeat binding factor signaling genes. This study provides insights into the evolutionary patterns and functions of the MATH gene families.