Populus cultivar:Hybrid cultivar of Populus nigra and Populus tomentosa Carr Transcriptome or Gene expression

Branching in woody plants affects their ecological benefits and impacts wood formation. To obtain genome-wide insights into the transcriptome changes and regulatory mechanisms associated with branching, we used high-throughput RNA sequencing to characterize cDNA libraries generated from active buds of Populus deltoides CL. 'zhonglin2025' (BC) and Populus×zhaiguanheibaiyang (NC). 'Populus×zhaiguanheibaiyang (NC)' is a new poplar cultivar bred our research group, which had a more branches and rapid growth. Populus deltoides CL. 'zhonglin2025' (BC) (Figure 1)is a fast-growing cultivar produced by cross breeding, and it has fewer branches than NC. In this study, we obtained a total of 198.2 million high-quality clean reads from the NC and BC libraries. We detected 3543 differentially expressed genes (DEGs) between the NC and BC libraries; 1418 were down-regulated and 2125 were up-regulated genes in the NC/BC comparisons. Gene Ontology functional classification of the differentially expressed genes indicated that they included 89 genes encoding proteins related to hormones biosynthesis, 364 related to hormone signaling transduction, and 104 related to auxin efflux transmembrane transporter. In addtion, we validated the expression profiles of the 16 DEGs by real-time quantitative PCR, and the results displayed similar expression pattern to those generated from high-throughput sequencing. Here, we identified global hormone regulatory patterns and differences in gene expression between NC and BC, and constructed a hormone regulatory network to explain branching in P. tomentosa buds. We also identified candidate genes for molecular breeding of particular plant types, and provided a starting point that will help in future investigations into the molecular mechanisms of branching in Populus.