小麦抗白粉病相关基因GST克隆与表达

以从小麦抗白粉病相关基因差异表达分析中获得的EST-3 (Genbank序列号EX567360)为标签,采用电子克隆的方法对其进行延伸,并对电子克隆结果进行半定量RT-PCR验证,最后对白粉菌不同侵染时间进行了表达分析.经RT-PCR扩增,EST-3表达的带型变化趋势与其在抑制性消减杂交SSH-cDNA的差异显示情况一致,且RT-PCR获得的序列与电子克隆的序列一致性达98％.生物信息学分析表明,该序列是由875 bp核苷酸组成的,具有完整的开放阅读框架,编码蛋白为229个氨基酸,GenBank序列号JK841279,含有一个N端和C端谷胱甘肽硫转移酶结构域,该序列与小麦谷胱甘肽硫转移酶基因(GST)一致性较高,达97％.表达分析结果显示,白粉菌侵染24 h表达受到抑制,48 h开始表达,侵染72 h表达最强,96 h又开始下降,表明GST基因属于白粉菌诱导型相关基因,参与小麦对白粉病的应答反应.

Cloning and Expression of Glutathione-S-transferase (GST) Gene Related to Powdery Mildew of Wheat

Batrachospermales is an order belonging to Florideophceae,Rhodophyta.It distributes all over the world.China and its adjacent regions are the distribution center.The small-subunit rDNA gene (SSU) sequences from species of Batrachospermales and their relative lineages were used to reconstruct the phylogenetic trees by using the PAUP^* 4.0b10 and MrBayes 3.1.2 software,which contained 12 samples collected from China and 28 species abroad obtained from GenBank.The results showed that the SSU region sequence was 1 871 bp with 709 variation sites (38%) and 169 parsimony informative sites (9%).The phylogenetic relationships were inferred using the maximum-likelihood,neighbor-joining,and Bayesian analysis,and three methods produced trees with largely congruent topology.All phylogenetic trees topology got a similar placement of Thoreales,which formed a monophyletic group with high bootstrap support.According to the Bayesian analysis,the conclusion supported that the Thoreales should be classified as a separate order.Three trees all revealed that Batrachospermum gelatinosum is separated from other members of Sect.Batrachospermum and should be classified as a separate Section.The genus Kumanoa should be admitted based on Sect.Contorta and Sect.Hybrida.