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 ...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。展开更多
miRNAs are a class of conserved, small, endogenous, and non-protein-coding RNA molecules with 20- 24 nucleotides （nt） in length that function as post-transcriptional modulators of gene expression in eukaryotic cells...miRNAs are a class of conserved, small, endogenous, and non-protein-coding RNA molecules with 20- 24 nucleotides （nt） in length that function as post-transcriptional modulators of gene expression in eukaryotic cells. Functional studies have demonstrated that plant miRNAs are involved in the regulation of a wide range of plant de- velopmental processes. To date, however, no research has been carried out to study the expression profiles of miRNAs in Gossypium raimondii, a model cotton species. We selected 16 miRNAs to profile their tissue-specific expression patterns in G. raimondii four different tissues, and these miRNAs are reported to play important roles in plant growth and development. Our results showed that the expression levels of these miRNAs varied significantly from one to another in a tissue-dependent manner. Eight miRNAs, including miR-159, miR-162, miR-164, miR-172, miR-390, miR-395, miR-397, and miR-398, exhibited exclusively high expression levels in flower buds, suggesting that these miRNAs may play significant roles in floral development. The expression level of miR-164 was relatively high in shoots beside flower buds, implying that the function of miR-164 is not only limited to floral development but it may also play an important role in shoot development. Certain miRNAs such as miR-166 and miR-160 were extremely highly expressed in all of the four tissues tested compared with other miRNAs investigated, suggesting that they may play regulatory roles at multiple development stages. This study will contribute to future studies on the functional charac- terization of rniRNAs in cotton.展开更多
文摘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。
基金supported by the US National Institute of Food and Agriculture(NIFA)the Cotton Incorporatedthe National NaturalScience Foundation of China(No.31170263)
文摘miRNAs are a class of conserved, small, endogenous, and non-protein-coding RNA molecules with 20- 24 nucleotides （nt） in length that function as post-transcriptional modulators of gene expression in eukaryotic cells. Functional studies have demonstrated that plant miRNAs are involved in the regulation of a wide range of plant de- velopmental processes. To date, however, no research has been carried out to study the expression profiles of miRNAs in Gossypium raimondii, a model cotton species. We selected 16 miRNAs to profile their tissue-specific expression patterns in G. raimondii four different tissues, and these miRNAs are reported to play important roles in plant growth and development. Our results showed that the expression levels of these miRNAs varied significantly from one to another in a tissue-dependent manner. Eight miRNAs, including miR-159, miR-162, miR-164, miR-172, miR-390, miR-395, miR-397, and miR-398, exhibited exclusively high expression levels in flower buds, suggesting that these miRNAs may play significant roles in floral development. The expression level of miR-164 was relatively high in shoots beside flower buds, implying that the function of miR-164 is not only limited to floral development but it may also play an important role in shoot development. Certain miRNAs such as miR-166 and miR-160 were extremely highly expressed in all of the four tissues tested compared with other miRNAs investigated, suggesting that they may play regulatory roles at multiple development stages. This study will contribute to future studies on the functional charac- terization of rniRNAs in cotton.
