木材是树木维管形成层活动的产物, 维管形成层活动具有周期性。这种周期性是树木特有的、适应环境变化的一种分生组织细胞状态转变现象, 对于树木适应环境变化及木材产量、品质形成具有重要意义。本项目将以杨树为材料，利用杨树维管形成层活动周期诱导实验体系,结合高通量测序、生物信息分析、酵母单杂、酵母双杂、免疫共沉淀和ChIP-qPCR等实验技术，研究维管形成层被动休眠、生理休眠和快速生长等阶段转换过程中的关键转录因子和microRNAs及其相互作用关系，构建形成层活动周期调控关键转录因子和microRNA调控网络。研究结果将为全面揭示维管形成层活动-休眠这种分生组织细胞状态周期性转变的分子机制提供实验证据, 也将为林业优质高产树种的推广生产、定向选育提供理论依据。

Wood is the product of vascular cambium of trees, and the cambium shows seasonal cycles of activity and dormancy, which is known as annual periodicity. This periodicity plays important roles in the wood formation and environmental adaptivity of trees. In this study, the cycles of activity and dormancy of poplar tree will be induced in experimental conditions, and deep seguencing, bioinformatics, yeast-1-hybridization, yeast-2-hybridization and ChIP-qPCR techniques will be used to study the transcription factors, microRNAs and their interaction during the cambial activity periodicity. The results will provide the experimental data for understanding the regulatory mechanisms of cambial activity periodicity, and will also provide a theoretical basis for forest breeding and production with high yield and quality.