Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.
Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China; College of Bee Science and Biomedicine, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.
Sci Total Environ. 2024 Dec 1;954:176369. doi: 10.1016/j.scitotenv.2024.176369. Epub 2024 Sep 17.
Brassinosteroids (BRs) and jasmonic acid (JA) are known to be involved in regulating plant responses to cadmium (Cd) stress. However, their specific roles and interaction in this process remain unclear. In this study, we discovered that exogenous BR alleviated Cd-mediated growth inhibition of rice seedlings. Enhanced Cd tolerance was also observed in m107, a BR-overproduction mutant. Phenotypic analysis of genetic materials involved in BR signaling confirmed the positive role of BR in regulating rice response to Cd toxicity. OsDLT, a key component in the BR signaling pathway, was found to be crucial for BR-mediated Cd tolerance. Further analysis demonstrated that activation of the BR pathway reduced the accumulation of Cd and reactive oxygen species (ROS) by modulating the expression of genes associated with Cd transport and ROS scavenging. Interestingly, transcriptome analysis indicated that the JA pathway was enriched in OsDLT-regulated differently expressed genes (DEGs). Gene expression and hormone assays showed that BR promoted the expression of JA pathway genes and JA levels in plants. Moreover, BR-induced tolerance was compromised in the JA signaling-deficient mutant osmyc2, suggesting that BR-mediated Cd resistance depends on the activation of the JA signaling pathway. Overall, our study revealed the synergistic interaction between BR and JA pathways in rice response to Cd stress, providing insights into the complex hormonal interplay in plant tolerance to heavy metals.
油菜素内酯（BRs）和茉莉酸（JA）被认为参与调节植物对镉（Cd）胁迫的响应。然而，它们在这个过程中的具体作用和相互作用仍不清楚。在本研究中，我们发现外源 BR 缓解了 Cd 介导的水稻幼苗生长抑制。BR 过量产生突变体 m107 也表现出增强的 Cd 耐受性。涉及 BR 信号转导的遗传材料的表型分析证实了 BR 在调节水稻对 Cd 毒性反应中的积极作用。OsDLT，BR 信号通路中的关键组成部分，被发现对 BR 介导的 Cd 耐受性至关重要。进一步的分析表明，BR 通路的激活通过调节与 Cd 转运和 ROS 清除相关的基因的表达，减少了 Cd 和活性氧（ROS）的积累。有趣的是，转录组分析表明，JA 通路在 OsDLT 调控的差异表达基因（DEGs）中富集。基因表达和激素测定表明，BR 促进了 JA 通路基因和植物中 JA 水平的表达。此外，在 JA 信号缺失突变体 osmyc2 中，BR 诱导的耐受性受损，表明 BR 介导的 Cd 抗性依赖于 JA 信号通路的激活。总的来说，我们的研究揭示了 BR 和 JA 通路在水稻应对 Cd 胁迫中的协同作用，为植物耐受重金属的复杂激素相互作用提供了新的见解。
