Liu Renjian, Wang Yuyuan, Shu Bingbing, Xin Jinyang, Yu Bingwei, Gan Yuwei, Liang Yonggui, Qiu Zhengkun, Yan Shuangshuang, Cao Bihao
Key Laboratory of Horticultural Crop Biology and Germplasm Innovation in South China, Ministry of Agriculture, College of Horticulture, South China Agricultural University, Guangzhou, China.
Guangdong Vegetable Engineering and Technology Research Center, South China Agricultural University, Guangzhou, China.
Plant Cell Environ. 2025 May;48(5):3085-3104. doi: 10.1111/pce.15339. Epub 2024 Dec 17.
High temperature (HT) is a major environmental factor that restrains eggplant growth and production. Heat shock factors (HSFs) play a vital role in the response of plants to high-temperature stress (HTS). However, the molecular mechanism by which HSFs regulate heat tolerance in eggplants remains unclear. Previously, we reported that SmEGY3 enhanced the heat tolerance of eggplant. Herein, SmHSFA8 activated SmEGY3 expression and interacted with SmEGY3 protein to enhance the activation function of SmEGY3 on SmCSD1. Virus-induced gene silencing (VIGS) and overexpression assays suggested that SmHSFA8 positively regulated heat tolerance in plants. SmHSFA8 enhanced the heat tolerance of tomato plants by promoting SlEGY3 expression, HO production and HO-mediated retrograde signalling pathway. DNA affinity purification sequencing (DAP-seq) analysis revealed that SmHSPs (SmHSP70, SmHSP70B and SmHSP21) and SmF3H were candidate downstream target genes of SmHSFA8. SmHSFA8 regulated the expression of HSPs and F3H and flavonoid content in plants. The silencing of SmF3H by VIGS reduced the flavonoid content and heat tolerance of eggplant. In addition, exogenous flavonoid treatment alleviated the HTS damage to eggplants. These results indicated that SmHSFA8 enhanced the heat tolerance of eggplant by activating SmHSPs exprerssion, mediating the SmEGY3-SmCSD1 module, and promoting SmF3H-mediated flavonoid biosynthesis.
高温（HT）是抑制茄子生长和产量的主要环境因素。热激因子（HSFs）在植物对高温胁迫（HTS）的响应中起着至关重要的作用。然而，HSFs调控茄子耐热性的分子机制仍不清楚。此前，我们报道SmEGY3增强了茄子的耐热性。在此，SmHSFA8激活SmEGY3表达并与SmEGY3蛋白相互作用，以增强SmEGY3对SmCSD1的激活功能。病毒诱导基因沉默（VIGS）和过表达分析表明，SmHSFA8正向调控植物的耐热性。SmHSFA8通过促进SlEGY3表达、HO产生和HO介导的逆行信号通路增强了番茄植株的耐热性。DNA亲和纯化测序（DAP-seq）分析表明，SmHSPs（SmHSP70、SmHSP70B和SmHSP21）和SmF3H是SmHSFA8的候选下游靶基因。SmHSFA8调控植物中HSPs和F3H的表达以及类黄酮含量。通过VIGS沉默SmF3H降低了茄子的类黄酮含量和耐热性。此外，外源类黄酮处理减轻了高温胁迫对茄子的损伤。这些结果表明，SmHSFA8通过激活SmHSPs表达、介导SmEGY3-SmCSD1模块以及促进SmF3H介导的类黄酮生物合成来增强茄子的耐热性。
