Abstract
Fuji, a major cultivar group of apple (Malus domestica), is extensively grown in China, Japan, and the USA. However, it has been experiencing prolonged differentiation of flower buds. and the potential mechanisms are largely unknown. Thus, for better comprehend the differentiation of apple flower buds, we performed a comparative transcriptomic and proteomic analysis between the closed (CK) and well-ventilated apple orchards (T) of 15-year-old ‘Nagano Fuji No.2’. In total, 12,211 and 8,290 differentially expressed genes (DEGs) and 473 and 534 differentially expressed proteins (DEPs) were identified in the CK group and T group, respectively. In both the expressional and translational levels, 14 up- and 156 down-regulated members were found in samples after flowering compared to pre-flowering in the CK group, respectively. In contrast, 31 up- and 131 down-regulated members were found in the T group. These members were mainly enriched in several Gene Ontology (GO) terms, such as "glycolytic process," "glucan biosynthetic process," and "response to water." These pathways were involved in the differentiation of flower buds regulated by light. Several genes, including MD13G1093200, MD06G1122100, MD15G1253900, MD13G1161400, MD07G1279200, MD15G1253900, and MD10G1289200, exhibited differential expression patterns between the CK and T groups, making them potential key candidates for additional functional analysis. Our findings provide a foundation for further research on the molecular mechanisms of light in flower bud differentiation.