A positive correlation of transcription trends between microarray and qRT-PCR was obtained. The 8 genes were ALDH, PK, pyruvate decarboxylase, glutamate dehydrogenase +), acetate-CoA ligase, adenylosuccinate synthase, asparagine synthase, and nitrite reductase, which changed Monensin sodium salt significantly under elevated CO2 concentrations. In terms of physiological processes, the growth parameter of diameter was significantly increased and net photosynthetic rate was decreased under elevated CO2 concentrations. Simultaneously, the changes in concentration of the four endogenous hormones appeared to actively promote plant development. These changes in physiological parameters prompted us to study the molecular processes at the transcriptome level. In this study, we focused on gene expression in the triploid white poplar leaf under elevated CO2 concentrations using gene chips, in order to MOPS, sodium salt confirm the key genes affected. Firstly, after the selection of 5,127 differentially expressed genes under elevated CO2 concentrations, a set of unique and representative expression profiles was identified. Significant profiles indicate that common functions attributable to the coexpressed genes. Such functions mainly indicate the biological characteristics. With this method, we explicitly considered the dynamic nature of gene expression profiles during clustering and confirmed a number of clear clusters. Second, after filtering the differentially expressed genes by significant expression profiles, functional annotation based on GO analysis showed that several genes functioned in metabolic process and response to stimulus of external environment, including response to light stimulus, radiation, abiotic stimulus and stress, the latter containing cellular response to stress, base-excision repair, DNA repair, and response to DNA damage stimulus. It is worthy of note that 31 genes participating in the function of ����response to stimulus of external environment���� contributed to the delivery of important signal molecules responding to elevated CO2. One gene for a photoreceptorinteracting protein was found, which showed decreased expression under T1 and increased expression under T2 treatment. In short, metabolism-related genes displayed considerable responses to elevated CO2. In addition, a similar phenomenon was found in KEGG analysis.