He Jiaojun, Chen Shutong, Chen Ru, Li Xinyu, Wu Jiahua, Zheng Yueping, Li Feifei, Zhan Yihua
College of Advanced Agricultural Sciences, Zhejiang A & F University, Hangzhou 311300, China.
Int J Mol Sci. 2024 Nov 28;25(23):12820. doi: 10.3390/ijms252312820.
Soil salinization is one of the abiotic stresses that inhibit plant growth and development, which seriously restricts global crop production. WRKY transcription factors play an important role in regulating plant responses to stress such as salt stress. In our previous study, two WRKY family genes from okra, and , were significantly up-regulated and down-regulated, respectively, in response to salt stress. In this study, subcellular localization showed that they were localized to the nucleus. The down-regulation of and via whole plant virus-induced gene silencing (VIGS) increased and decreased plant sensitivity to salt stress, respectively. Ectopic expression of and led to promoted and reduced salt tolerance in transgenic , respectively. There was no significant difference between transgenic plants and wild type (WT) without salt treatment. Salt stress significantly inhibited plant growth. The decrease of chlorophyll content and the increase of anthocyanin content in -overexpressed transgenic plants were lower than those in the WT, while -overexpressed plants had the opposite effect. Under salt stress, the -overexpressed plants had the highest malondialdehyde (MDA) content, followed by the WT, and the lowest in -overexpressed plants. The hydrogen peroxide (HO) content and superoxide anion (O) generation rate were only slightly increased. Moreover, salt stress significantly increased plant proline content and antioxidant enzyme activities, which was highest in -overexpressed plants except superoxide dismutase (SOD). Taken together, these results suggest that AeWRKY32 and AeWRKY70 play positive and negative roles in plant in response to salt stress, respectively.
土壤盐渍化是抑制植物生长发育的非生物胁迫之一，严重制约着全球作物产量。WRKY转录因子在调节植物对盐胁迫等胁迫的反应中发挥着重要作用。在我们之前的研究中，来自秋葵的两个WRKY家族基因，分别在盐胁迫下显著上调和下调。在本研究中，亚细胞定位显示它们定位于细胞核。通过全株病毒诱导基因沉默（VIGS）下调和分别增加和降低了植物对盐胁迫的敏感性。和的异位表达分别导致转基因拟南芥的耐盐性增强和降低。未经盐处理的转基因植物与野生型（WT）之间没有显著差异。盐胁迫显著抑制植物生长。过表达转基因植物中叶绿素含量的降低和花青素含量的增加低于野生型，而过表达植物则有相反的效果。在盐胁迫下，过表达植物的丙二醛（MDA）含量最高，其次是野生型，过表达植物中最低。过氧化氢（H₂O₂）含量和超氧阴离子（O₂⁻）产生速率仅略有增加。此外，盐胁迫显著增加了植物脯氨酸含量和抗氧化酶活性，除超氧化物歧化酶（SOD）外，过表达植物中的这些指标最高。综上所述，这些结果表明AeWRKY32和AeWRKY70在植物对盐胁迫的反应中分别发挥正、负作用。
