Zhou Xiangui, Sun Zhaofei, Huang Yuanzhi, He Dan, Lu Lu, Wei Mengting, Lin Shuangmei, Luo Wenxi, Liao Xiaozhen, Jin Songsong, Guo Manyuan, Hao Lingyun, Jiang Zhonghao
College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518000, China.
College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518000, China.
Plant Physiol Biochem. 2025 Feb;219:109408. doi: 10.1016/j.plaphy.2024.109408. Epub 2024 Dec 18.
Salt damage is a major issue that causes a decline in crop yield. WRKY transcription factors (TFs) extensively regulate plant biotic and abiotic stress responses, growth, and development. WRKY45 is crucial in regulating leaf senescence, low phosphorus responses, and cadmium stress response in Arabidopsis. However, the involvement of WRKY45 in salinity and osmotic stress responses is unclear. Here, we report that WRKY45 plays a vital role in responding to salinity and osmotic stress. NaCl and sorbitol treatments upregulate WRKY45 expression. Furthermore, the overexpression of WRKY45 (WRKY45-OXs) may enhance the tolerance of Arabidopsis to salinity and osmotic stress. Moreover, the root length, fresh weight, chlorophyll, and proline content were significantly higher in WRKY45-OXs than in the wide type (WT) Col-0 plants after salt or PEG treatment, whereas malondialdehyde and reactive oxygen species (ROS) levels were significantly lower than in the WT plants. Correspondingly, the overexpression of WRKY45 modulated the expression of stress-responsive genes. Dual luciferase assay and electrophoretic mobility shift assay further confirmed that WRKY45 can activate the promoter of RD29A by directly binding to specific W-box cis-acting elements. Overall, our experimental evidence suggesting that WRKY45 mainly acts as a key regulator coordinating the response to high salinity and osmotic stress through mechanisms dependent on ABA signaling along with enhanced antioxidant capacity.
盐害是导致作物产量下降的一个主要问题。WRKY转录因子广泛调控植物的生物和非生物胁迫反应、生长及发育。WRKY45在拟南芥中对叶片衰老、低磷反应及镉胁迫反应的调控中起关键作用。然而，WRKY45在盐胁迫和渗透胁迫反应中的作用尚不清楚。在此，我们报道WRKY45在响应盐胁迫和渗透胁迫中起重要作用。NaCl和山梨醇处理上调WRKY45的表达。此外，WRKY45过表达植株（WRKY45-OXs）可能增强拟南芥对盐胁迫和渗透胁迫的耐受性。而且，在盐或聚乙二醇（PEG）处理后，WRKY45-OXs的根长、鲜重、叶绿素和脯氨酸含量显著高于野生型（WT）Col-0植株，而丙二醛和活性氧（ROS）水平显著低于WT植株。相应地，WRKY45过表达调控了胁迫响应基因的表达。双荧光素酶测定和电泳迁移率变动分析进一步证实WRKY45可通过直接结合特定的W-box顺式作用元件来激活RD29A的启动子。总体而言，我们的实验证据表明WRKY45主要作为一个关键调节因子，通过依赖脱落酸（ABA）信号传导的机制以及增强的抗氧化能力来协调对高盐和渗透胁迫的响应。
