Genome-Wide Identification, Characterization, and Expression Analysis of BBX Genes During Anthocyanin Biosynthesis in Mango (Mangifera indica L.)

Chengkun Yang, Muhammad Mobeen Tahir, Yawen Zhang, Xiaowen Wang, Wencan Zhu, Feili Li, Kaibing Zhou, Qin Deng, Minjie Qian

Biology (Basel); 2025 Jul 23; 14(8):919. doi: 10.3390/biology14080919.

Abstract

B-box (BBX) transcription factors are critical regulators of light-mediated anthocyanin biosynthesis, influencing peel coloration in plants. To explore their role in red mango cultivars, we identified 32 BBX genes (MiBBX1-MiBBX32) in the mango (Mangifera indica L.) genome using a genome-wide analysis. Phylogenetic and structural analyses classified these genes into five subfamilies based on conserved domains. A collinearity analysis revealed segmental duplication as the primary mechanism of MiBBX gene family expansion, with purifying selection shaping their evolution. A promoter analysis identified numerous light- and hormone-responsive cis-elements, indicating regulatory roles in the light and hormonal signaling pathways. Expression profiling in the 'Sensation' cultivar revealed organ-specific patterns, with several MiBBX genes showing higher expression in the peel than in the flesh. Many of these genes also consistently exhibited elevated expression in the peel of red-skinned cultivars ('Sensation' and 'Guifei') compared to yellow and green cultivars, suggesting their role in red peel pigmentation. Furthermore, postharvest light treatment of 'Hongmang No. 6' fruit significantly upregulated multiple MiBBX genes, suggesting their involvement in light-induced anthocyanin accumulation in red mango peel. These findings provide valuable insights into the molecular mechanisms governing light-regulated peel coloration in mango and establish a foundation for functional studies of MiBBX genes in fruit pigmentation.

See https://pubmed.ncbi.nlm.nih.gov/40906093/

Figure 2

Schematic representation of MiBBX chromosomal distribution and interchromosomal relationships. Gray lines depict all syntenic blocks across the mango genome, while red lines highlight collinear BBX gene pairs. Chromosome numbers are indicated at the base of each chromosome. The colors within the ring represent the varying levels of gene density, ranging from red to yellow. The farther the red line is from the center of the circle, the higher the gene density is.