Zheng Anru, Tian Caiyun, Zhou Chengzhe, Yang Niannian, Wen Shengjing, Hu Xiaowen, Zhang Zhendong, Fang Jiaxin, Lai Zhongxiong, Guo Yuqiong
Anxi College of Tea Science, College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
Anxi College of Tea Science, College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
Plant Physiol Biochem. 2025 May;222:109758. doi: 10.1016/j.plaphy.2025.109758. Epub 2025 Mar 8.
Heat and drought are the stressors with significant adverse impacts on the yield stability of tea plants. The heat shock proteins 60 (HSP60s) play important roles in protecting plants under heat stress. However, the mechanism of HSP60s under heat and drought stresses remains unclear. Here, we identified 19 CsHSP60s (namely CsHSP60-1 to CsHSP60-19) in tea plants and classified them into three groups based on phylogenetic analysis. In addition, studies on gene duplication events during the evolutionary process demonstrated that CsHSP60 members were subjected to purify selection. Analysis of cis-acting elements revealed the presence of numerous stress and hormone-responsive elements within the promoter regions of CsHSP60s. Real-time quantitative fluorescent PCR (qRT-PCR) analyses demonstrated that CsHSP60s rapidly responded to heat and combined heat and drought stress while exhibiting a delayed response to drought stress. The inhibition of eight CsHSP60 genes via antisense oligodeoxynucleotide (AsODN) resulted in more severe damage and ROS accumulation. Specifically, CsHSP60-9, CsHSP60-16, and CsHSP60-19 exhibited notable reductions in Fv/Fm values and displayed increased accumulation of HO and O. These observations indicated a potential role for CsHSP60 in mitigating ROS accumulation under stress conditions, thereby enhancing tea plants' resilience to heat and drought stresses. Using a yeast two-hybrid (Y2H) assay, we identified that CsHSP60-2 and CsHSP60-16 physically interact with CsCPN10-4 and CsCPN10-5, respectively. These interactions suggest a cooperative chaperone activity between CsHSP60 and CsCPN10 in response to combined heat and drought stress. These findings lay a foundation for further understanding the involvement of HSP60s in the tolerance mechanisms to compound heat and drought stresses.
高温和干旱是对茶树产量稳定性产生重大不利影响的胁迫因素。热激蛋白60（HSP60s）在保护植物免受热胁迫方面发挥着重要作用。然而，HSP60s在高温和干旱胁迫下的作用机制仍不清楚。在此，我们在茶树中鉴定出19个CsHSP60s（即CsHSP60-1至CsHSP60-19），并根据系统发育分析将它们分为三组。此外，对进化过程中基因复制事件的研究表明，CsHSP60成员受到纯化选择。顺式作用元件分析表明，CsHSP60s启动子区域存在大量胁迫和激素响应元件。实时定量荧光PCR（qRT-PCR）分析表明，CsHSP60s对高温以及高温和干旱复合胁迫迅速做出反应，而对干旱胁迫的反应则延迟。通过反义寡脱氧核苷酸（AsODN）抑制8个CsHSP60基因会导致更严重的损伤和活性氧积累。具体而言，CsHSP60-9、CsHSP60-16和CsHSP60-19的Fv/Fm值显著降低，且HO和O的积累增加。这些观察结果表明，CsHSP60在减轻胁迫条件下的活性氧积累方面具有潜在作用，从而增强茶树对高温和干旱胁迫的耐受性。通过酵母双杂交（Y2H）试验，我们确定CsHSP60-2和CsHSP60-16分别与CsCPN10-4和CsCPN10-5发生物理相互作用。这些相互作用表明，在应对高温和干旱复合胁迫时，CsHSP60和CsCPN10之间存在协同伴侣活性。这些发现为进一步了解HSP60s在复合高温和干旱胁迫耐受机制中的作用奠定了基础。
