Collaborative Innovation Center of Natural Rubber, Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, School of Plant Protection, Hainan University Haikou, 570228, PR China; Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, Ministry of Agriculture and Rural Affairs, PR China; Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan 571101, PR China.
Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, Ministry of Agriculture and Rural Affairs, PR China; Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan 571101, PR China.
Gene. 2022 Jun 15;827:146475. doi: 10.1016/j.gene.2022.146475. Epub 2022 Apr 1.
Heat shock protein 90 (HSP90), an essential molecular chaperone, is triggered in response to stress situations in plants. However, the roles of HSP90 gene family members in rubber tree have not been totally specified. In this study, 7 HbHSP90 genes were identified from rubber tree genome. Classification of HbHSP90 family genes into three groups, namely A, B, and C was based on phylogenetic analysis. The structural and motif analyses showed similar structural features in the same group of HbHSP90 members, but differences between groups. Analysis of cis-regulatory element sequences of HbHSP90 genes indicates that the HbHSP90 gene promoter is rich in drought, temperature, and hormone elements. qRT-PCR analysis showed that the 7 HbHSP90 genes responded in different degrees to temperature, drought and powdery mildew infection, and in particularly, HbHSP90.1 was differentially expressed under both abiotic and biotic stresses. Meanwhile, HbHSP90.1 gene was significantly expressed under the treatment of different phytohormone and HO (Hydrogen Peroxide) treatments, which means that HbHSP90.1 gene performs an essential part in the growth and development of rubber trees. Furthermore, the protein interaction results showed that HbHSP90.1 interacted with HbSGT1b. Subcellular localization showed that both HbHSP90.1 and HbSGT1b located in the nucleus. Taken together, we speculate that HbHSP90.1 interacts with HbSGT1b in the nucleus to respond to rubber tree stress processes. The results of this study provide a solid foundation for further studies on the mechanism of HbHSP90 family genes in the stress resistance response of rubber tree.
热休克蛋白 90（HSP90）是一种重要的分子伴侣，它在植物应对应激情况时被触发。然而，橡胶树 HSP90 基因家族成员的作用尚未完全确定。在本研究中，从橡胶树基因组中鉴定出 7 个 HbHSP90 基因。根据系统发育分析，将 HbHSP90 家族基因分为 A、B 和 C 三组。结构和基序分析表明，同一组 HbHSP90 成员具有相似的结构特征，但不同组之间存在差异。HbHSP90 基因顺式调控元件序列分析表明，HbHSP90 基因启动子富含干旱、温度和激素元件。qRT-PCR 分析表明，7 个 HbHSP90 基因对温度、干旱和白粉病感染的响应程度不同，特别是 HbHSP90.1 在非生物和生物胁迫下差异表达。同时，HbHSP90.1 基因在不同植物激素和 HO（过氧化氢）处理下均有显著表达，这意味着 HbHSP90.1 基因在橡胶树的生长发育中起着重要作用。此外，蛋白相互作用结果表明，HbHSP90.1 与 HbSGT1b 相互作用。亚细胞定位表明，HbHSP90.1 和 HbSGT1b 均定位于细胞核。综上所述，我们推测 HbHSP90.1 在细胞核中与 HbSGT1b 相互作用，以响应橡胶树的应激过程。本研究结果为进一步研究 HbHSP90 家族基因在橡胶树胁迫响应中的作用机制提供了坚实的基础。
