Zhu Xi, Duan Xiaoqin, Luo Junfu, Guan Nengkang, Zheng Haifei, Majeed Yasir, Zou Huafen, Jin Hui, Chen Zhuo, Zhang Yu
Key Laboratory of Tropical Fruit Biology, Ministry of Agriculture and Rural Affairs/Key Laboratory of Hainan Province for Postharvest Physiology and Technology of Tropical Horticultural Products, South Subtropical Crops Research Institute, Chinese Academy of Tropical Agricultural Sciences, Zhanjiang, Guangdong, China.
National Key Laboratory for Tropical Crop Breeding, Sanya Research Institute, Chinese Academy of Tropical Agricultural Sciences, Sanya, China.
Front Plant Sci. 2025 Jul 21;16:1634338. doi: 10.3389/fpls.2025.1634338. eCollection 2025.
Heat stress severely impacts the growth and development of potato plants. However, the molecular mechanisms underlying thermotolerance, particularly the role of WRKY transcription factors (TFs), remain poorly understood. Here, we identified as a heat-responsive gene in potato, demonstrating significant transcriptional upregulation under 30°C and 35°C heat stress conditions. Phylogenetic analysis classified StWRKY65 into the WRKY Group II family, revealing high evolutionary conservation with its tomato ortholog SlWRKY65. Subcellular localization confirmed its nuclear targeting. Additionally, we generated transgenic potato lines with overexpression (OE) or RNA interference (RNAi)-mediated suppression of the target gene. Under heat stress, OE lines exhibited enhanced thermotolerance, manifested through improvements in plant height, fresh/dry weights of plants and roots, tuber yield, photosynthetic efficiency, transpiration rate, and stomatal conductance. Concurrently, compared to non-transgenic (NT) controls, overexpression significantly elevated the activities of antioxidant enzymes (ascorbate peroxidase [APX], catalase [CAT], peroxidase [POD], superoxide dismutase [SOD]), proline accumulation, and total chlorophyll content, while reducing malondialdehyde (MDA) and hydrogen peroxide (HO) levels. Conversely, RNAi lines displayed heightened heat sensitivity, impaired growth parameters, diminished antioxidant capacity, and elevated oxidative stress markers. Furthermore, overexpression transcriptionally activated key antioxidant enzyme-related genes (, , , , , ), whereas its knockdown produced opposing effects. This study demonstrates the pivotal role of in enhancing potato thermotolerance by simultaneously boosting antioxidant defenses and maintaining photosynthetic efficiency under heat stress. As climate change intensifies thermal extremes, these findings position as a valuable genetic target for developing heat-resistant potato varieties, offering a timely strategy to protect this vital crop and global food security.
热胁迫严重影响马铃薯植株的生长发育。然而，耐热性的分子机制，特别是WRKY转录因子（TFs）的作用，仍知之甚少。在此，我们鉴定出一个马铃薯中的热响应基因，该基因在30°C和35°C热胁迫条件下表现出显著的转录上调。系统发育分析将StWRKY65归类到WRKY第II组家族，显示其与番茄直系同源基因SlWRKY65具有高度的进化保守性。亚细胞定位证实其定位于细胞核。此外，我们构建了过表达（OE）或RNA干扰（RNAi）介导的靶基因抑制的转基因马铃薯株系。在热胁迫下，OE株系表现出增强的耐热性，表现为株高、植株和根系鲜重/干重、块茎产量、光合效率、蒸腾速率和气孔导度的提高。同时，与非转基因（NT）对照相比，过表达显著提高了抗氧化酶（抗坏血酸过氧化物酶[APX]、过氧化氢酶[CAT]、过氧化物酶[POD]、超氧化物歧化酶[SOD]）的活性、脯氨酸积累和总叶绿素含量，同时降低了丙二醛（MDA）和过氧化氢（H₂O₂）水平。相反，RNAi株系表现出更高的热敏感性、生长参数受损、抗氧化能力下降和氧化应激标记物升高。此外，过表达转录激活了关键抗氧化酶相关基因（APX、CAT、POD、SOD、GR、DHAR），而其敲低则产生相反的效果。本研究表明，StWRKY65在热胁迫下通过同时增强抗氧化防御和维持光合效率来提高马铃薯耐热性方面起着关键作用。随着气候变化加剧极端高温，这些发现使StWRKY65成为培育耐热马铃薯品种的有价值的遗传靶点，为保护这种重要作物和全球粮食安全提供了及时的策略。
