Zhu Zhi-Peng, Yu Jian-Xiang, Liu Fang-Fang, Zhu De-Wei, Xiong Ai-Sheng, Sun Miao
College of Marine and Biological Engineering, Yancheng Teachers University, Yancheng, Jiangsu, 224002, China.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China.
J Plant Physiol. 2023 Aug;287:154062. doi: 10.1016/j.jplph.2023.154062. Epub 2023 Aug 1.
Okra (Abelmoschus esculentus L.) is a tropical crop species, and its growth and development are severely affected by cold stress. Recent studies have identified a potential association between WRKY transcription factors and the cold response mechanism of crops. In this study, the AeWRKY32 transcription factor that encodes 482 amino acids was amplified from A. esculentus, and its expression level was found to be the highest in the okra flower. AeWRKY32 localized to the nucleus and displayed transcriptional activation capability. Under normal conditions, overexpression of AeWRKY32 induced anthocyanin accumulation, with higher expression levels of AtCHS1, AtCHI4, AtF3H1, and AtDFR2 in transgenic Arabidopsis. Under cold stress, anthocyanin levels were further elevated in transgenic Arabidopsis plants. At the same time, AeWRKY32 overexpression promoted ABA biosynthesis, inhibited HO and O generation, induced stomatal closure, reduced electrolyte leakage, and thus improved the cold resistance of transgenic Arabidopsis. Furthermore, under cold stress, the expression profiles of AtCOR413, AtCOR15B, AtCBF1, and AtCBF2 were upregulated in transgenic Arabidopsis. Overall, our study provides evidence that AeWRKY32 serves as a crucial regulator in both anthocyanin accumulation and cold tolerance of transgenic Arabidopsis. Our findings could provide insights into the molecular mechanism linking AeWRKYs to plant cold tolerance.
秋葵（Abelmoschus esculentus L.）是一种热带作物，其生长发育受到冷胁迫的严重影响。最近的研究已经确定WRKY转录因子与作物的冷响应机制之间存在潜在关联。在本研究中，从秋葵中扩增出编码482个氨基酸的AeWRKY32转录因子，发现其在秋葵花中的表达水平最高。AeWRKY32定位于细胞核并具有转录激活能力。在正常条件下，AeWRKY32的过表达诱导花青素积累，转基因拟南芥中AtCHS1、AtCHI4、AtF3H1和AtDFR2的表达水平较高。在冷胁迫下，转基因拟南芥植株中的花青素水平进一步升高。同时，AeWRKY32的过表达促进ABA生物合成，抑制H₂O₂和O₂产生，诱导气孔关闭，减少电解质渗漏，从而提高转基因拟南芥的抗寒性。此外，在冷胁迫下，转基因拟南芥中AtCOR413、AtCOR15B、AtCBF1和AtCBF2的表达谱上调。总体而言，我们的研究提供了证据表明AeWRKY32在转基因拟南芥的花青素积累和耐寒性中均起关键调节作用。我们的发现可为AeWRKYs与植物耐寒性之间的分子机制提供见解。
