Key Laboratory of Sweetpotato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs/Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis and Utilization, Ministry of Education, College of Agronomy & Biotechnology, China Agricultural University, Beijing 100193, China.
College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China.
Biomolecules. 2020 Mar 27;10(4):506. doi: 10.3390/biom10040506.
WRKYs play important roles in plant growth, defense regulation, and stress response. However, the mechanisms through which WRKYs are involved in drought and salt tolerance have been rarely characterized in sweetpotato [ (L.) Lam.]. In this study, we cloned a gene, , from sweetpotato and its expression was induced with PEG6000, NaCl, and abscisic acid (ABA). The IbWRKY2 was localized in the nucleus. The full-length protein exhibited transactivation activity, and its active domain was located in the N-terminal region. IbWRKY2-overexpressing Arabidopsis showed enhanced drought and salt tolerance. After drought and salt treatments, the contents of ABA and proline as well as the activity of superoxide dismutase (SOD) were higher in transgenic plants, while the malondialdehyde (MDA) and HO contents were lower. In addition, several genes related to the ABA signaling pathway, proline biosynthesis, and the reactive oxygen species (ROS)-scavenging system, were significantly up-regulated in transgenic lines. These results demonstrate that IbWRKY2 confers drought and salt tolerance in Arabidopsis. Furthermore, IbWRKY2 was able to interact with IbVQ4, and the expression of was induced by drought and salt treatments. These results provide clues regarding the mechanism by which IbWRKY2 contributes to the regulation of abiotic stress tolerance.
WRKYs 在植物生长、防御调控和应激响应中发挥重要作用。然而，WRKYs 参与抗旱和耐盐性的机制在甘薯 [（L.）Lam.] 中很少被描述。在这项研究中，我们从甘薯中克隆了一个基因，IbWRKY2，其表达受 PEG6000、NaCl 和脱落酸（ABA）诱导。IbWRKY2 定位于细胞核中。全长蛋白具有转录激活活性，其活性域位于 N 端区域。过表达 IbWRKY2 的拟南芥表现出增强的抗旱和耐盐性。在干旱和盐处理后，转基因植物中 ABA 和脯氨酸的含量以及超氧化物歧化酶（SOD）的活性更高，而丙二醛（MDA）和 HO 的含量更低。此外，与 ABA 信号通路、脯氨酸生物合成和活性氧（ROS）清除系统相关的几个基因在转基因系中显著上调。这些结果表明 IbWRKY2 赋予拟南芥抗旱和耐盐性。此外，IbWRKY2 能够与 IbVQ4 相互作用，并且表达受干旱和盐处理诱导。这些结果为 IbWRKY2 参与调节非生物胁迫耐受性的机制提供了线索。
