Key Laboratory of Landscaping Agriculture, Ministry of Agriculture and Rural Affairs/Key Laboratory of Biology of Ornamental Plants in East China, National Forestry and Grassland Administration, College of Horticulture, Nanjing Agricultural University, Nanjing, China.
Jiangsu Graduate Workstation/Lily Science and Technology Backyard in Qixia of Jiangsu, Nanjing, China.
Plant Cell Environ. 2024 Dec;47(12):4702-4719. doi: 10.1111/pce.15058. Epub 2024 Jul 29.
Heat stress transcription factors (HSFs) are core factors of plants in response to heat stress (HS), but their regulatory network is complicated and remains elusive in a large part, especially HSFBs. In this study, we reported that the LlERF012-LlHSFA1 module participates in heat stress response (HSR) by directly regulating HSF pathway in lily (Lilium longiflorum). LlHSFB1 was confirmed as a positive regulator in lily thermotolerance and a heat-inducible AP2/ERF member LlERF012 (Ethylene Response Factor 012) was further identified to be a direct trans-activator of LlHSFB1. Overexpression of LlERF012 elevated the thermotolerance of transgenic Arabidopsis and lily, but silencing LlERF012 reduced thermotolerance in lily. Further analysis showed LlERF012 interacted with LlHSFA1, which led to enhanced transactivation activity and DNA-binding capability of LlERF012. In addition, LlERF012 also directly activated the expression of LlHSFA1 by binding its promoter. As expected, we found that LlERF012 bound the promoters of LlHSFA2, LlHSFA3A, and LlHSFA3B to stimulate their expression, and LlERF012-LlHSFA1 interaction enhanced these activation effects. Overall, our data suggested that LlERF012 was a key factor for lily thermotolerance and the LlERF012-LlHSFA1 interaction synergistically regulated the activity of the HSF pathway including the class A and B members, which might be of great significance for coordinating the functions of different HSFs.
热应激转录因子（HSFs）是植物应对热应激（HS）的核心因子，但它们的调控网络在很大程度上仍然很复杂，难以捉摸，尤其是 HSFBs。在这项研究中，我们报道 LlERF012-LlHSFA1 模块通过直接调节百合中的 HSF 途径参与热应激反应（HSR）。LlHSFB1 被确认为百合耐热性的正调控因子，而热诱导的 AP2/ERF 成员 LlERF012（Ethylene Response Factor 012）被进一步鉴定为 LlHSFB1 的直接转录激活子。LlERF012 的过表达提高了转基因拟南芥和百合的耐热性，但 LlERF012 的沉默降低了百合的耐热性。进一步的分析表明 LlERF012 与 LlHSFA1 相互作用，导致 LlERF012 的转录激活活性和 DNA 结合能力增强。此外，LlERF012 还通过结合其启动子直接激活 LlHSFA1 的表达。不出所料，我们发现 LlERF012 结合了 LlHSFA2、LlHSFA3A 和 LlHSFA3B 的启动子，以刺激它们的表达，并且 LlERF012-LlHSFA1 相互作用增强了这些激活效应。总的来说，我们的数据表明 LlERF012 是百合耐热性的关键因素，LlERF012-LlHSFA1 相互作用协同调节 HSF 途径的活性，包括 A 类和 B 类成员，这对于协调不同 HSFs 的功能可能具有重要意义。
