甲基化是蛋白质和核酸的一种重要修饰，能够调节基因表达和关闭，是表观遗传学的重要研究内容。6-甲基腺嘌呤 (m6A)，是发生在RNA碱基A第六位N原子上的甲基化，抑制或敲除 m6A 甲基转移酶均会引起重要表型变化，成为近年来表观遗传修饰研究的崭新领域。然而，目前已有关于m6A修饰的报道主要集中在动物和人类上，在植物领域尚不多见，与树木生长发育相关的m6A修饰机制的研究仍未见报道。针对前人工作的不足，本项目以我国重要造林生态树种毛白杨为材料，针对树木发育年周期性生长不同时期之间的交替转换，运用MeRIP-seq测序分析技术，结合细胞生物学、生物化学以及生物信息学等检测手段，在全转录组水平对m6A修饰位点进行探究，挖掘鉴定毛白杨中调控其维管形成层周期性转换的关键位点及作用模式，解析和阐释m6A修饰对树木维管形成层周期性转换的调控机理，为进一步揭示树木次生生长季节循环的表观遗传分子机理奠定基础。

Methylation is an important modification in proteins and nucleic acids, which can regulate gene expression and shut down, and is one of the significant contents in epigenetics research. N6-methyladenosine (m6A) is the most prevalent and internal modification that occurs in the messenger RNAs (mRNA) of most eukaryotes. Recent studies have discovered inhibition or knockout of m6A methyltransferase causes significant phenotypic changes, thus becoming a brand new field of epigenetic modification research now (Niu et al., 2013). Nevertheless, reports about RNA m6A modification mainly focus on the study of animal and human diseases, and related research is still rare in the field of plant. So far, the investigations related to the mechanism of RNA methylation modification in trees growth remain quite limited. In this project, we will use MeRIP-seq technology coupled with cell biology, biochemistry and bioinformatics detections to present the transcriptome-wide m6A modification profiling effort for the phase transition of vascular cambium in Populus tomentosa. First, we will analyze the key m6A modification sites and the model in the regulation of the phase transition of vascular cambium activity. In addition, we will identify and determine the biological function of these key sites. Finally, based on the results, we will further explore the molecular mechanism of RNAm6A methylated modification in regulation of the phase transition of vascular cambium activity in poplar. Surely, the results of this study will lay foundation for the further investigation of regulation mechanism for tree secondary growth and cambial differentiation, and provide a valuable resource for wood properties related tree breeding.