Genome-wide identification and characterization of MADS-box gene family of Rhododendron griersonianum Balf. f. et Forrest

MADS-box genes play an important role in plant growth and development, especially in processes such as floral organ formation, flowering time regulation, and fruit development and ripening. Based on whole-genome sequencing data of Rhododendron griersonianum Balf. f. et Forrest, 81 MADS-box genes were identified and analyzed using bioinformatics methods. Phylogenetic analysis and protein structure classification divided these genes into two classes, including 24 genes in Type-Ⅰand 57 genes in Type-Ⅱ. The MADS-box genes were unevenly distributed across 12 chromosomes, with no genes located on chromosome 2. Among the 81 MADS-box genes, six pairs showed segmental duplications and one pair showed tandem duplication, all of which have undergone purifying selection. The promoter regions of the MADS-box genes contained elements involved in light response, plant growth, hormone response, and stress response. Overall, the identification of MADS-box gene family members provides a reliable reference for further studies on the biological functions of MADS-box proteins in R. griersonianum