Genome-wide identification and analysis of the MADS-box gene family and its potential role in fruit ripening in black raspberry (Rubus occidentalis L.)

Abstract

BACKGROUND: Black raspberry is a vital fruit crop with a high antioxidant function. MADS-box genes play an important role in the regulation of fruit development in angiosperms. OBJECTIVE: To understand the regulatory role of the MADS-box family, a total of 80 MADS-box genes were identified and analyzed. METHODS: The MADS-box genes in the black raspberry genome were analyzed using bioinformatics methods. Through an analysis of the promoter elements, the possible functions of different members of the family were predicted. The spatiotemporal expression patterns of members of the MADS-box family during black raspberry fruit development and ripening were systematically analyzed. RESULTS: The genes were classified into type I (Mα: 33; Mβ: 6; Mγ: 10) and type II (MIKC*: 2; MIKCC: 29) genes. We also obtained a complete overview of the RoMADS-box gene family through phylogenetic, gene structure, conserved motif, and cis element analyses. The relative expression analysis showed different expression patterns, and most RoMADS-box genes were more highly expressed in fruit than in other tissues of black raspberry. CONCLUSIONS: This finding indicates that the MADS-box gene family is involved in the regulation of fruit ripening processes in black raspberry.