Transcriptome analysis reveals key genes involved in rhizome bud germination of Cephalostachyum pingbianense in four seasons

Cephalostachyum pingbianense is the only known bamboo species that can produce bamboo shoots in four seasons under natural conditions. Nevertheless, the regulatory mechanisms of shoot bud differentiation and development of that is still unknown. In this study, RNA sequencing and differentially expressed gene analysis were performed on dormant rhizome bud (DR), growing rhizome bud (GR) and germinative bud (GB) of C. pingbianense in each season. The results showed that rhizome bud germination of C. pingbianense was cooperatively regulated by multiple pathways such as carbohydrate metabolism, hormone signal transduction, cell wall biogenesis, temperature response, water metabolism and so on. Putative major regulatory genes of each season, such as HK and BGLU4 in spring, GUX2 and GH3 in winter, GPI and talA/talB in summer and autumn, were identified through protein-protein interaction network analyses. We propose that dynamic changes of phytohormones and the differential expression of these genes contribute to the rhizome bud germination of C. pingbianense in four seasons.