【摘要】 DNA甲基化主要是通过在甲基转移酶的催化下修饰基因组DNA来响应外界环境的胁迫，是表观遗传学的重要手段之一，参与植物中DNA甲基化起始的主要DNA甲基转移酶是DRM2。文章通过美国国家生物技术信息中心(National Center for Biotechnology Information, NCBI)数据库，在番茄中发现了一个与拟南芥胞嘧啶甲基转移酶DRM2同源性较高的序列，即SlDRM2L。通过GenBank(登录号NM_-001246974)获得番茄DNA甲基转移酶SlDRM2L基因的cDNA全长序列。实时荧光定量聚合酶链式反应(polymerase chain reaction, PCR)结果表明SlDRM2L在所有组织中均有表达，叶和花的表达量最高。同时利用烟草瞬时表达系统将构建的绿色荧光瞬时表达载体35S::SlDRM2L-GFP用于亚细胞定位实验，通过激光共聚焦显微镜观察可知SlDRM2L蛋白定位于细胞核中；此外，在高温条件下(39℃,4 h),番茄SlDRM2L的基因转录水平明显提高，表明SlDRM2L介导的DNA甲基化可能受高温诱导。该文为发现SlDRM2L在植物生长发育中的作用提供了相关的科学依据，为深入研究SlDRM2L的功能奠定了理论基础。更多还原

【Abstract】 The DNA methylation catalyzed by DNA methyltransferase modifies genomic DNA to respond to stress of external environment, which is one of the important means of epigenetics. The main DNA methyltransferase involved in the initiation of DNA methylation in plants is DRM2. In this paper, through the National Center for Biotechnology Information(NCBI) database of USA, a sequence with high homology to Arabidopsis cytosine methyltransferase DRM2 was found, namely SlDRM2L. The full-length cDNA of tomato DNA methyltransferase SlDRM2L gene was obtained from GenBank(accession number NM_-001246974). Quantitative real-time polymerase chain reaction(qRT-PCR) revealed that the expression of SlDRM2L was in all tissues of tomato, but higher expression in leaves and flowers. At the same time, the transient expression system of tobacco was used to construct the green fluorescent transient expression vector 35 S::S1DRM2L-GFP for subcellular localization experiments. The observation through the laser confocal microscope revealed that SlDRM2 L was expressed in the nucleus; In addition, SlDRM2L transcription level was significantly increased under high temperature(39 ℃, 4 h), suggesting that SlDRM2L-mediated DNA methylation may be induced by high temperature. This paper provides relevant scientific basis for discovering the role of SlDRM2L in plant growth and development, and lays a theoretical foundation for in-depth study on the function of SlDRM2L.更多还原