The full-length c DNA of functionally-unknown salivary protein C002 in Schizaphis graminum was cloned using rapid amplification of c DNA ends（RACE） and designated as Sg C002（Gen Bank accession no. KC977563）. It is...The full-length c DNA of functionally-unknown salivary protein C002 in Schizaphis graminum was cloned using rapid amplification of c DNA ends（RACE） and designated as Sg C002（Gen Bank accession no. KC977563）. It is 767 bp long and encodes a protein of 190 amino acid residues with a predicted mass of 21.5 k Da and a predicted cleavage site of N-terminal signal peptide between the 24 th and the 25 th residues. Sg C002 is specifically expressed in salivary gland with the highest level at the 2nd instar. Introducing Sg C002-specific 476-si RNA, but not 546-si RNA to aphids through artificial diet significantly suppressed Sg C002 expression. Silencing Sg C002 gene led to lethality of the aphid on wheat plants, but not on pure artificial diet. Our study demonstrated that artificial diet-mediated RNAi can be a useful tool for research on the roles of genes in aphid salivary gland, and also provided new insights into the characteristics of C002 in wheat aphids.展开更多
基金supported by the National Natural Science Foundation of China (30971920,31371946)the International Cooperation Project between China and Belgium (2010DFA32810)the Earmarked Fund for Modern Agro-Industry Technology Research System,China (CARS3)
文摘The full-length c DNA of functionally-unknown salivary protein C002 in Schizaphis graminum was cloned using rapid amplification of c DNA ends（RACE） and designated as Sg C002（Gen Bank accession no. KC977563）. It is 767 bp long and encodes a protein of 190 amino acid residues with a predicted mass of 21.5 k Da and a predicted cleavage site of N-terminal signal peptide between the 24 th and the 25 th residues. Sg C002 is specifically expressed in salivary gland with the highest level at the 2nd instar. Introducing Sg C002-specific 476-si RNA, but not 546-si RNA to aphids through artificial diet significantly suppressed Sg C002 expression. Silencing Sg C002 gene led to lethality of the aphid on wheat plants, but not on pure artificial diet. Our study demonstrated that artificial diet-mediated RNAi can be a useful tool for research on the roles of genes in aphid salivary gland, and also provided new insights into the characteristics of C002 in wheat aphids.
文摘通过cDNA末端快速扩增技术（rapid amplification of cDNA ends,RACE）从益母草（Leonurus heterophyllus Sweet）叶片中克隆获得了一个编码糖基转移酶的基因（LhsUGT）。该基因cDNA全长为1562 bp,开放阅读框（open reading frame,ORF）为1368 bp,编码455个氨基酸残基,其分子量和等电点分别为50.47 k D和5.52。生物信息学分析结果显示：LhsUGT编码的酶蛋白含有3种二级结构,其中α螺旋占43.1%,β折叠片占17.5%,无规卷曲占39.4%,其C端还发现了一段高度保守的PSPG结构域,说明LhsUGT编码的酶蛋白属于植物糖基转移酶超家族;对LhsUGT的氨基酸序列进行BLAST同源比对,发现益母草与其它植物的糖基转移酶序列相似性为26.4%-68.0%;系统进化树分析表明,LhsUGT蛋白属于拟南芥糖基转移酶超家族的L组,故推测它可能具有催化简单酚类发生糖基化的功能;SDS-PAGE电泳显示,原核表达系统成功表达出分子量约为69 k D的LhsUGT重组蛋白,其N端含有一段17.9 k D的His标签,且在IPTG诱导5 h后达到最高表达量。本研究结果为进一步开展体外酶促反应、阐明益母草糖基转移酶的生物学功能奠定了基础。
