Shandong Dry-land Farming Technology Key Laboratory, College of Agronomy, Qingdao Agricultural University / Peanut Industry Cooperative Innovation Center, Qingdao, 266109, Shandong, China.
Shandong Dry-land Farming Technology Key Laboratory, College of Agronomy, Qingdao Agricultural University / Peanut Industry Cooperative Innovation Center, Qingdao, 266109, Shandong, China.
Plant Physiol Biochem. 2021 Mar;160:175-183. doi: 10.1016/j.plaphy.2021.01.014. Epub 2021 Jan 17.
Peanut is an important oilseed crop whose production is threatened by various abiotic and biotic stresses. Study of the molecular mechanism of salt tolerance could provide important information for the salt tolerance of this crop. WRKY transcription factors (TFs) are one of the largest TF families in plants and are involved in growth and development, defense regulation and the stress response. Here, we cloned a novel WRKY transcription factor gene belonging to the WRKY IIc subfamily, AhWRKY75, from the salt-tolerant mutant M34. The expression of AhWRKY75 was induced by NaCl stress treatment. After salt treatment, AhWRKY75-overexpressing peanuts grew better than wild-type plants. Furthermore, several genes related to the reactive oxygen species (ROS) scavenging system were up-regulated; the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were significantly higher in transgenic lines than in non-transgenic control plants; and the malondialdehyde (MDA) and superoxide anion contents were significantly lower in transgenic lines than in control plants. The net photosynthetic rate (Pn), stomatal conductance (GS) and transpiration rate (Tr) of transgenic lines were significantly higher in transgenic plants than in control plants, and the intercellular CO concentration (Ci) was significantly lower in transgenic plants than in control plants. These results demonstrated that the AhWRKY75 gene conferred salt tolerance in transgenic peanut lines by improving the efficiency of the ROS scavenging system and photosynthesis under stress treatment. This study identifies a novel WRKY gene for enhancing the tolerance of peanut and other plants to salt stress.
花生是一种重要的油料作物，其生产受到各种非生物和生物胁迫的威胁。研究耐盐性的分子机制可为该作物的耐盐性提供重要信息。WRKY 转录因子（TFs）是植物中最大的 TF 家族之一，参与生长发育、防御调节和应激反应。在这里，我们从耐盐突变体 M34 中克隆了一个属于 WRKY IIc 亚家族的新型 WRKY 转录因子基因 AhWRKY75。AhWRKY75 的表达受 NaCl 胁迫处理诱导。盐处理后，AhWRKY75 过表达的花生比野生型植物生长得更好。此外，几种与活性氧（ROS）清除系统相关的基因上调；超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）的活性在转基因株系中明显高于非转基因对照植物；而丙二醛（MDA）和超氧阴离子含量在转基因株系中明显低于对照植物。转基因株系的净光合速率（Pn）、气孔导度（GS）和蒸腾速率（Tr）明显高于对照植物，而胞间 CO2 浓度（Ci）明显低于对照植物。这些结果表明，AhWRKY75 基因通过提高胁迫处理下 ROS 清除系统和光合作用的效率赋予转基因花生耐盐性。本研究鉴定了一个新的 WRKY 基因，用于增强花生和其他植物对盐胁迫的耐受性。
