Transcriptome analysis of axillary bud differentiation in a new dual-axillary bud genotype of sugarcane

Each node of the sugarcane stem has a single axillary bud. Therefore, to ensure yield, a large number of cane setts are required for planting, which increases production costs. The dual-axillary bud genotype could provide two buds in a same node so as to reduce the amount of cane setts and ensure enough buds when same sowing planted. To studying the molecular characteristics of this genotype, we performed transcriptome sequencing (RNA-seq) analysis with between the dual-axillary bud genotype and its sister line, the single-axillary bud genotype at the axillary bud differentiation stage. A total of 84.78 Gb clean data were obtained, with an average of 10.90 Gb clean data from each genotype. By aligning to the databases, a total of 50,248 unigenes were functionally annotated. 1646 differentially expressed genes (543 up-regulated and 1103 down-regulated genes) were identified between the two genotypes. The expression of genes involved in the carotenoid pathway including F-box proteins, SCF protein complex, and α/β-hydrolase fold enzymes were down-regulated, 9-cis-epoxycarotenoid dioxygenase was up-regulated, the P450 family exhibited both up- and down- regulated. And genes related to shoot branching, including WRKY transcription factors, the Myb-like DNA-binding domain gene family, and bHLH transcription factors showed both up- and down- regulated, the NAC domain gene family, GRAS gene family, bZIP transcription factors, and R2R3-MYB transcription factors all exhibited down-regulated. Overall, we predict that the dual-axillary bud trait in sugarcane may be related to the significant expression of genes involved in the strigolactone pathway, as well as in genes or transcription factors related to shoot branching.