College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China.
College of Biological Sciences and Technology, Yili Normal University, Yili, 830500, Xinjiang, China.
Plant Physiol Biochem. 2024 Nov;216:109086. doi: 10.1016/j.plaphy.2024.109086. Epub 2024 Sep 1.
Drought stress strongly restricts the growth, development, and yield of wheat worldwide. Among the various transcription factors (TFs) involved in the wheat drought response, the specific functions of many basic leucine zipper (bZIP) TFs related to drought tolerance are still not well understood. In this study, we focused on the bZIP TF TabZIP156 in wheat. Our analysis showed that TabZIP156 was highly expressed in both roots and leaves, and it responded to drought and abscisic acid (ABA) stress. Through subcellular localization and transactivation assays, we confirmed that TabZIP156 was located to the nucleus and functioned as a transcriptional activator. Overexpression of TabZIP156 in Arabidopsis enhanced drought tolerance, as evidenced by higher germination rate, longer root length, lower water loss rate, reduced ion leakage, increased proline accumulation, decreased levels of HO, O and MDA, and improved activities of POD, SOD, and CAT enzymes. Additionally, the expression of drought- and antioxidant-related genes were significantly upregulated in TabZIP156 transgenic Arabidopsis under drought stress. However, silencing TabZIP156 in wheat led to decreased proline content, increased accumulation of HO, O and MDA, reduced activities of antioxidant enzymes, and downregulation of many drought- and antioxidant-related genes under drought stress. Furthermore, the dual-luciferase assay demonstrated that TabZIP156 could activate the expression of TaP5CS, TaDREB1A, and TaPOD by binding to their promoters. Taken together, this study highlights the significant role of TabZIP156 in drought stress and provides valuable insights for its potential application in breeding drought-resistant wheat.
干旱胁迫强烈限制了小麦在全球范围内的生长、发育和产量。在参与小麦干旱响应的各种转录因子（TFs）中，许多与耐旱性相关的基本亮氨酸拉链（bZIP）TFs 的具体功能仍不为人所理解。在本研究中，我们专注于小麦中的 bZIP TF TabZIP156。我们的分析表明，TabZIP156 在根和叶中均高度表达，并且对干旱和脱落酸（ABA）胁迫有响应。通过亚细胞定位和转录激活测定，我们证实 TabZIP156 定位于细胞核，并作为转录激活子发挥作用。TabZIP156 在拟南芥中的过表达增强了耐旱性，表现在更高的发芽率、更长的根长、更低的水分损失率、减少的离子渗漏、脯氨酸积累增加、HO、O 和 MDA 水平降低以及 POD、SOD 和 CAT 酶活性提高。此外，在干旱胁迫下，TabZIP156 转基因拟南芥中与干旱和抗氧化相关的基因表达显著上调。然而，在小麦中沉默 TabZIP156 导致脯氨酸含量降低、HO、O 和 MDA 积累增加、抗氧化酶活性降低以及许多与干旱和抗氧化相关的基因表达下调。此外，双荧光素酶测定表明，TabZIP156 可以通过结合其启动子来激活 TaP5CS、TaDREB1A 和 TaPOD 的表达。综上所述，本研究强调了 TabZIP156 在干旱胁迫中的重要作用，并为其在培育耐旱小麦中的潜在应用提供了有价值的见解。
