College of Ecology and the Environment, Nanjing Forestry University, Nanjing, Jiangsu 210037, China; State Key Laboratory of Tree Genetics and Breeding, College of Life Sciences, Nanjing Forestry University, Nanjing, Jiangsu 210037, China; Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China; National Positioning Observation Station of Hung-tse Lake Wetland Ecosystem in Jiangsu Province, Hongze, Jiangsu 223100, China.
College of Ecology and the Environment, Nanjing Forestry University, Nanjing, Jiangsu 210037, China.
J Hazard Mater. 2023 Sep 15;458:131991. doi: 10.1016/j.jhazmat.2023.131991. Epub 2023 Jul 14.
Hormesis is important in plant performance in contaminated environments, but the underlying genetic mechanisms are poorly understood. This study aimed at mining key genes in regulating Cd-induced hormesis in Arabidopsis thaliana and verifying their biological function. Hormesis of fresh weight, dry weight, and root length occurred at concentrations of 0.003-2.4, 0.03-0.6, and 0.03-0.6 µM Cd, respectively. Superoxide dismutase and catalase activities, and chlorophyll content displayed inverted U-shaped curves, indicating that the antioxidant defense system and photosynthesis system played roles in hormesis. Based on KEGG pathway analysis with the trend chart of differentially expressed genes and weighted correlation network analysis, the key gene ABF1 in the metabolic pathway of abscisic acid was identified. Subsequently, genetic experiments with wild, overexpressing, and knockdown lines of A. thaliana were conducted to further verify the biological function of ABF1 involving Cd-induced hormesis in A. thaliana. The results revealed that the resistance capability of the overexpressing type to Cd stress was significantly enhanced and implicated that the ABF1 gene is essential for Cd-induced hormesis in A. thaliana. Mining key genes that regulate Cd-induced hormesis in plants and stimulate them could have a transformative impact on the phytoremediation of metal-contaminated environments.
植物在污染环境中的性能受胁迫诱导现象（Hormesis）的影响，但其潜在的遗传机制尚未被充分了解。本研究旨在挖掘调控拟南芥Cd 诱导胁迫诱导现象的关键基因，并验证其生物学功能。结果表明，在 0.003-2.4、0.03-0.6 和 0.03-0.6µM Cd 浓度下，鲜重、干重和根长分别出现胁迫诱导现象。超氧化物歧化酶和过氧化氢酶活性以及叶绿素含量呈倒“U”型曲线，表明抗氧化防御系统和光合作用系统在胁迫诱导现象中发挥作用。基于差异表达基因的趋势图和加权相关网络分析的 KEGG 途径分析，确定代谢途径中脱落酸的关键基因 ABF1。随后，通过野生型、过表达和敲低拟南芥的遗传实验，进一步验证了 ABF1 基因参与拟南芥 Cd 诱导胁迫诱导现象的生物学功能。过表达型对 Cd 胁迫的抗性能力显著增强，表明 ABF1 基因对拟南芥 Cd 诱导胁迫诱导现象至关重要。挖掘调控植物 Cd 诱导胁迫诱导现象的关键基因并对其进行刺激，可能会对金属污染环境的植物修复产生变革性影响。
