木薯MeTPP1基因克隆、结构变异及其表达分析

Gene Cloning,Structure Variation,and Expression Analysis of MeTPP1 in Cassava

旨在研究木薯MeTPP1基因在干旱、低温等非生物胁迫响应中的作用。用同源基因克隆的方法从木薯叶片中克隆MeTPP1基因,用MEGA软件构建Neighbor-joining系统进化树,用Dna SP软件分析基因结构变异,用实时荧光定量PCR技术分析MeTPP1基因在不同胁迫处理下的表达特性。结果表明,MeTPP1基因含有一个1 131 bp的开放阅读框,编码376个氨基酸,含有TPP家族保守结构域。系统进化树分析表明,MeTPP1与杨树和杞柳中同源基因的亲缘关系较近,序列相似性分别为77.8%和74.5%。基因结构变异发现,MeTPP1在木薯野生种和栽培种之间共有9个错义突变,它们可能与MeTPP1的表达有关。实时荧光定量PCR分析表明,MeTPP1表达量受到干旱、低温和ABA处理的响应。上述结果表明,MeTPP1在转录水平参与ABA介导的木薯干旱和低温胁迫,可作为候选基因进一步研究其在木薯抗逆中的功能。

This work is to reveal the roles of MeTPP1 gene in abiotic stresses such as drought and cold in cassava. Homology-based cloning method was used to clone MeTPP1 gene from cassava leaves, MEGA software to construct its neighbor-joining phylogenetic tree, DnaSP software to analyze its structural variations, and quantitative RT-PCR （ qRT-PCR ） to explore its expression characteristics under different abiotic treatments. The results showed that geue, MeTPP] had a 1 131 bp open reading frame encoding 376 amino acids, and contained a conserved domain of TPP gene family. Phylogenetic analysis revealed that MeTPP1 had close genetic relationship to its homologues from Populus trichocarpa and Salix purpurea, and the sequence similarity was 77.8% and 74.5%, respectively. Genetic structural variation showed that a total of nine mis-sense mutations, which might he related to the expression of MeTPP1, were identified between cassava wild and cultivated species, qRT-PCR analysis demonstrated that the expression of MeTPP1 significantly changed in response to drought, cold, and ABA treatments. Together, these results indicate that MeTPP1 is involved in ABA-mediated drought and cold stresses of cassava at the transcriptional level, and can be served as a candidate to further study its functions in resistance of abiotic stress in cassava.