Ectopic expression of CSD1 and CSD2 targeting genes of miR398 in grapevine is associated with oxidative stress tolerance
Ectopic expression of CSD1 and CSD2 targeting genes of miR398 in grapevine is associated with oxidative stress tolerance
复制标题
葡萄中 CSD1 和 CSD2 靶向 miR398 基因的异位表达与氧化应激耐受性相关
DOI：
10.1007/s10142-017-0565-9
复制
发表时间：
2017-11-01
影响因子：
2.9
通讯作者：
Fang, Jinggui
中科院分区：
文献类型：
--
作者：
Leng, XiangPeng;Wang, Peipei;Fang, Jinggui
microRNAs（miRNAs）是一类长度约为21个核苷酸的内源性小分子RNA，在转录后水平上通过调控mRNA的切割或翻译抑制而在植物的多种生理过程中发挥重要作用。先前的研究表明，响应于氧化胁迫的miR 398的下调允许两个靶基因，细胞溶质CSD 1和叶绿体CSD 2（铜/锌超氧化物歧化酶）的上调，从而保护植物耐受氧化胁迫。在这项研究中，我们提供的证据表明，葡萄藤miR 398（Vv-miR 398），通过调节其靶基因，VvCSD 1和VvCSD 2的表达，介导葡萄藤铜（Cu）胁迫的反应，这已被放大，由于增加含铜农药的应用。不同浓度的Cu胁迫抑制了Vv-miR 398的表达;另一方面，VvCSD 1和VvCSD 2基因的活性稳步上升。通过在转基因烟草（Nicotiana tabacum）中过量表达VvCSD 1和VvCSD 2来彻底检查VvCSD 1和VvCSD 2在Cu胁迫下的功能。我们发现，这两个过表达的转基因株系与野生型相比，具有较低的铜敏感性和较高的铜耐受性。此外，在高铜条件下，与野生型相比，转基因株系中积累了较低水平的ROS和较高水平的SOD活性。此外，这些转基因烟草品系还记录了比WT植物更高的UV和盐耐受性。这些结果表明，过表达VvCSD将增强ROS清除系统，并保护植物免受更多的氧化损伤。此外，需要在这方面进行更多的调查，这将大大提高我们对水果作物对环境胁迫的抗性的理解。
MicroRNAs (miRNAs) are endogenous small RNAs of -21 nucleotides that play an important role in diverse plant physiological processes at the post-transcriptional level by directing mRNA cleavage or translational inhibition. Previous studies have indicated that down-regulation of miR398 in response to oxidative stress allows up-regulation of the two target genes, cytosolic CSD1 and chloroplastic CSD2 (copper/zinc superoxide dismutase), resulting in protecting the plants to tolerate oxidative stress. In this study, we provide evidence that grapevine miR398 (Vv-miR398), by regulating the expression of its target genes, VvCSD1 and VvCSD2, mediates responses of grapevine to copper (Cu) stress which have been magnified due to increase in Cu-containing pesticide application. The expression of Vv-miR398 was inhibited by different concentrations of Cu stress; on the other hand, there was a steady increase in the activity of VvCSD1 and VvCSD2 genes. The function of VvCSD1 and VvCSD2 under Cu stress was thoroughly examined by overexpressing the use of the VvCSD1 and VvCSD2 in transgenic tobacco (Nicotiana tabacum). We found that both the overexpressed transgenic lines had lower Cu sensitivity and higher Cu tolerance compared with the wild type. In addition, lower levels of ROS and higher levels of SOD activities were accumulated in the transgenic lines in comparison with the wild type under the higher Cu conditions. Furthermore, these transgenic tobacco lines also recorded a higher UV and salt tolerance than the WT plants. These results suggested that overexpressing the VvCSDs will enhance the ROS-scavenging systems and protect the plant against more oxidative damage. Also, more investigations in this line are needed that would provide significant improvements in our understanding the resistance of fruit crops to environmental stress.