Genome-Wide Identification and Analysis of the MADS-Box Gene Family in American Beautyberry ().

The MADS-box gene family encodes a number of transcription factors that play key roles in various plant growth and development processes from response to environmental cues to cell differentiation and organ identity, especially the floral organogenesis, as in the prominent ABCDE model of flower development. Recently, the genome of American beautyberry () has been sequenced. It is a shrub native to the southern region of United States with edible purple-colored berries; it is a member of the family, a family of medical and agricultural importance. Seventy-eight MADS-box genes were identified from 17 chromosomes of the assembled genome. Peptide sequences blast and analysis of phylogenetic relationships with MADS-box genes of , , , and were performed. Genes were separated into 32 type I and 46 type II MADS-box genes. MADS-box genes were clustered into four groups: MIKC, MIKC*, Mα-type, and Mγ-type, while the Mβ-type group was absent. Analysis of the gene structure revealed that from 1 to 15 exons exist in MADS-box genes. The number of exons in type II MADS-box genes (5-15) greatly exceeded the number in type I genes (1-9). The motif distribution analysis of the two types of MADS-box genes showed that type II MADS-box genes contained more motifs than type I genes. These results suggested that MADS-box genes type II had more complex structures and might have more diverse functions. The role of MIKC-type MADS-box genes in flower and fruit development was highlighted when the expression profile was analyzed in different organs transcriptomes. This study is the first genome-wide analysis of the MADS-box gene family, and the results will further support any functional and evolutionary studies of MADS-box genes and serve as a reference for related studies of other plants in the medically important family.