Dao Mei, Zhang Zhiyu, Yin Xian, Wang Jianzhao, Qin Ying, Yu Longfeng, Wu Tian
Southwest Landscape Architecture Engineering Research Center of National Forestry and Grassland Administration, College of Landscape Architecture and Horticulture Science, Southwest Forestry University, Kunming, Yunnan, China.
Yunnan Key Laboratory of tea Germplasm Conservation, Lincang, Yunnan, China.
Physiol Plant. 2025 Jul-Aug;177(4):e70430. doi: 10.1111/ppl.70430.
The intercropping of tea plants with Chinese chestnut has been recognized as an advanced and eco-friendly cultivation method that enhances the self-resistance of tea plants. This study aimed to investigate the relationship between plant hormones and CsAFS1 based on previous findings and to reveal the mechanism by which CsAFS1 enhances the resistance of tea plants intercropped with Chinese chestnut. In this study, an α-farnesene synthase (AFS) was identified in tea plants intercropped with Chinese chestnut through transcriptome sequencing. This gene was actively expressed during cold and under exogenous methyl jasmonate (MeJA), salicylic acid (SA), abscisic acid (ABA), and gibberellic acid (GA) induction. The gene was cloned, and the bioinformatics analysis revealed that its encoded protein was clustered within the same evolutionary branch as camellia proteins, and hence it was named CsAFS1. The promoter analysis revealed multiple cis-acting elements responsive to cold, JA, MeJA, and SA. After transformation of CsAFS1 into tobacco plants, the transgenic tobacco plants exhibited growth similar to that of wild-type tobacco plants, but with longer and denser glandular trichomes. Aphid and cold stress were used as representative examples of biotic and abiotic stresses in transgenic tobacco plants, respectively. Enhanced resistance to aphid and cold stress was associated with increased levels of osmoregulatory substances and protective enzyme activities, upregulated expression of stress-related genes, and reduced reactive oxygen species production. CsAFS1 was also found to respond rapidly to MeJA and SA, and significant changes in terpenoid content, for example, nerolidol, were observed. These findings suggested that CsAFS1 enhanced stress resistance by boosting antioxidant enzyme activity, the level of osmoregulatory substances, and secondary metabolites, hormone signaling, and systemic acquired resistance, making tea plants or tea plantations much healthier. This study provided a theoretical foundation for understanding stress regulation in tea plants and for breeding stress-resistant varieties.
茶树与板栗间作已被认为是一种先进且环保的栽培方法，可增强茶树的自身抗性。本研究旨在基于先前的研究结果，探究植物激素与CsAFS1之间的关系，并揭示CsAFS1增强与板栗间作茶树抗性的机制。在本研究中，通过转录组测序在与板栗间作的茶树中鉴定出一种α-法尼烯合酶（AFS）。该基因在低温以及外源茉莉酸甲酯（MeJA）、水杨酸（SA）、脱落酸（ABA）和赤霉素（GA）诱导下均有活跃表达。该基因被克隆，生物信息学分析表明其编码的蛋白质与山茶属植物蛋白质聚集在同一进化分支内，因此将其命名为CsAFS1。启动子分析揭示了多个对低温、茉莉酸（JA）、MeJA和SA有响应的顺式作用元件。将CsAFS1转化到烟草植株中后，转基因烟草植株的生长与野生型烟草植株相似，但腺毛更长且更密集。分别以蚜虫和低温胁迫作为转基因烟草植株生物胁迫和非生物胁迫的代表实例。对蚜虫和低温胁迫抗性的增强与渗透调节物质水平和保护酶活性的增加、胁迫相关基因表达上调以及活性氧产生减少有关。还发现CsAFS1对MeJA和SA反应迅速，并且观察到萜类化合物含量有显著变化，例如橙花叔醇。这些发现表明，CsAFS1通过提高抗氧化酶活性、渗透调节物质水平和次生代谢产物、激素信号传导以及系统获得性抗性来增强胁迫抗性，使茶树或茶园更加健康。本研究为理解茶树中的胁迫调节以及培育抗逆品种提供了理论基础。
