Chen Sique, Cao Hongrui, Huang Baolin, Zheng Xiujuan, Liang Kangjing, Wang Guo-Liang, Sun Xinli
Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Department of Plant Science and Technology, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China.
Department of Plant Pathology, Ohio State University, Columbus, Ohio, USA.
Plant Cell Environ. 2022 Jul;45(7):2126-2144. doi: 10.1111/pce.14329. Epub 2022 May 1.
WRKY transcription factors (TFs) play crucial roles in biotic and abiotic stress responses. However, their roles in thermal response are still largely elusive, especially in rice. In this study, we revealed the functions of WRKY10 TF and VQ8 protein containing VQ motif in rice thermotolerance. Overexpression of WRKY10 or loss of VQ8 function increases thermosensitivity, whereas conversely, overexpression of VQ8 or loss of WRKY10 function enhances thermotolerance. Overexpression of WRKY10 accelerates reactive oxygen species (ROS) accumulation in chloroplasts and apoplasts, and it also induces the expression of heat shock TF and protein genes. We also found that WRKY10 regulates nuclear DNA fragmentation and hypersensitive response by modulating NAC4 TF expression. The balance between destructive and protective responses in WRKY10-overexpression plant is more fragile and more easily broken by heat stress compared with wild type. In vitro and in vivo assays revealed that VQ8 interacts with WRKY10 and inhibits the transcription activity via repressing its DNA-binding activity. Our study demonstrates that WRKY10 negatively regulates thermotolerance by modulating the ROS balance and the hypersensitive response and that VQ8 functions antagonistically to positively regulate thermotolerance. The functional module of WRKY10-VQ8 provides safe and effective regulatory mechanisms in the heat stress response.
WRKY转录因子（TFs）在生物和非生物胁迫响应中发挥着关键作用。然而，它们在热响应中的作用仍 largely难以捉摸，尤其是在水稻中。在本研究中，我们揭示了WRKY10转录因子和含有VQ基序的VQ8蛋白在水稻耐热性中的功能。WRKY10的过表达或VQ8功能的丧失会增加热敏感性，反之，VQ8的过表达或WRKY10功能的丧失会增强耐热性。WRKY10的过表达会加速叶绿体和质外体中活性氧（ROS）的积累，还会诱导热激TF和蛋白基因的表达。我们还发现WRKY10通过调节NAC4转录因子的表达来调控核DNA片段化和过敏反应。与野生型相比，WRKY10过表达植株中破坏和保护反应之间的平衡更脆弱，更容易被热胁迫打破。体外和体内试验表明，VQ8与WRKY10相互作用并通过抑制其DNA结合活性来抑制转录活性。我们的研究表明，WRKY10通过调节ROS平衡和过敏反应对耐热性起负调控作用，而VQ8则起拮抗作用对耐热性起正调控作用。WRKY10-VQ8功能模块在热胁迫响应中提供了安全有效的调控机制。
