Genome-Wide Characterization of CaM/CML Gene Family in Cabbage (Brassica oleracea var. capitata): Expression Profiling and Functional Implications During Hyaloperonospora parasitica Infection

Calmodulin (CaM) and calmodulin-like proteins (CMLs) are crucial for calcium signal transduction in plants. Although <i>CaM</i>/<i>CML</i> genes have been extensively studied in various plant species, research on these genes in <i>Brassica oleracea</i> is still limited. In this study, 14 <i>BoCaM</i> and 75 <i>BoCML</i> genes were identified in the <i>B. oleracea</i> genome through a genome-wide search. Phylogenetic analysis categorized these genes, along with their homologs in <i>Arabidopsis</i> and rice, into six distinct groups. All <i>BoCaM</i>/<i>BoCML</i> genes were unevenly distributed across the nine chromosomes of <i>B. oleracea</i>, with 52 of them lacking introns. Collinearity analysis revealed that <i>CaM</i>/<i>CML</i> genes in <i>Arabidopsis</i> are present in multiple copies in the <i>B. oleracea</i> genome. Moreover, the majority of <i>BoCaM</i>/<i>BoCML</i> genes exhibited distinct expression patterns across the different tissues, indicating their role in the growth and development of <i>B. oleracea</i>. A clustering heatmap of <i>BoCaM</i>/<i>BoCML</i> gene expression showed distinct patterns before and four days after <i>Hyaloperonospora parasitica</i> infection, dividing the genes into five groups based on their expression patterns. Notably, <i>BoCML46-2</i> is significantly downregulated in both susceptible and resistant materials, suggesting that it plays an important role in responding to <i>H. parasitica</i> infection. This study conducted a comprehensive survey of the <i>BoCaM/BoCML</i> gene family in <i>B. oleracea</i>. It could serve as a theoretical foundation for further functional identification and utilization of family members and their role in the interaction between <i>B. oleracea</i> and <i>H. parasitica</i>.