Yang Jiaheng, Qu Xiao, Li Tao, Gao Yixiang, Du Haonan, Zheng Lanjie, Ji Manchun, Zhang Paifeng, Zhang Yan, Hu Jinxin, Liu Liangyu, Lu Zefu, Yang Zijian, Zhang Huiyong, Yang Jianping, Jiao Yongqing, Zheng Xu
College of Agronomy, State Key Laboratory of Wheat and Maize Crop Science, and Center for Crop Genome Engineering, Longzi Lake Campus, Henan Agricultural University, Zhengzhou, 450046, China.
College of Life Science, Henan Agricultural University, Zhengzhou, 450002, China.
J Integr Plant Biol. 2023 Jan;65(1):45-63. doi: 10.1111/jipb.13372. Epub 2022 Dec 31.
Integration of light signaling and diverse abiotic stress responses contribute to plant survival in a changing environment. Some reports have indicated that light signals contribute a plant's ability to deal with heat, cold, and stress. However, the molecular link between light signaling and the salt-response pathways remains unclear. We demonstrate here that increasing light intensity elevates the salt stress tolerance of plants. Depletion of HY5, a key component of light signaling, causes Arabidopsis thaliana to become salinity sensitive. Interestingly, the small heat shock protein (sHsp) family genes are upregulated in hy5-215 mutant plants, and HsfA2 is commonly involved in the regulation of these sHsps. We found that HY5 directly binds to the G-box motifs in the HsfA2 promoter, with the cooperation of HISTONE DEACETYLASE 9 (HDA9), to repress its expression. Furthermore, the accumulation of HDA9 and the interaction between HY5 and HDA9 are significantly enhanced by salt stress. On the contrary, high temperature triggers HY5 and HDA9 degradation, which leads to dissociation of HY5-HDA9 from the HsfA2 promoter, thereby reducing salt tolerance. Under salt and heat stress conditions, fine tuning of protein accumulation and an interaction between HY5 and HDA9 regulate HsfA2 expression. This implies that HY5, HDA9, and HsfA2 play important roles in the integration of light signaling with salt stress and heat shock response.
光信号与多种非生物胁迫反应的整合有助于植物在不断变化的环境中生存。一些报告表明，光信号有助于植物应对热、冷和胁迫的能力。然而，光信号与盐反应途径之间的分子联系仍不清楚。我们在此证明，增加光照强度可提高植物的耐盐胁迫能力。光信号的关键成分HY5的缺失会导致拟南芥对盐分敏感。有趣的是，小热激蛋白（sHsp）家族基因在hy5-215突变体植物中上调，且HsfA2通常参与这些sHsp的调控。我们发现，HY5在组蛋白去乙酰化酶9（HDA9）的协同作用下直接结合到HsfA2启动子中的G-box基序上，以抑制其表达。此外，盐胁迫显著增强了HDA9的积累以及HY5与HDA9之间的相互作用。相反，高温触发HY5和HDA9降解，导致HY5-HDA9从HsfA2启动子上解离，从而降低耐盐性。在盐和热胁迫条件下，蛋白质积累的微调以及HY5与HDA9之间的相互作用调节HsfA2的表达。这意味着HY5、HDA9和HsfA2在光信号与盐胁迫和热激反应的整合中发挥重要作用。
