Xu Yu, Ni Longjie, Yu Chaoguang, Hua Jianfeng, Yin Yunlong, Gu Chunsun, Wang Zhiquan
Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China; State Key Laboratory of Tree Genetics and Breeding, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China.
Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China; Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Nanjing 210014, China.
Plant Sci. 2025 Mar;352:112378. doi: 10.1016/j.plantsci.2024.112378. Epub 2024 Dec 27.
Hibiscus hamabo Sieb. et Zucc. (H. hamabo) is a semi-mangrove plant with excellent stress tolerance that plays a crucial role in the ecological restoration of saline and alkaline areas. It is an ideal candidate species for studying the mechanisms involved in stress tolerance. Although the MYB gene family has preliminarily been characterized in H. hamabo, the specific functions and action mechanisms of the R2R3-MYB genes in this species have not fully been elucidated. In this study, 190 R2R3-MYB genes were identified at the genomic level using bioinformatics methods. The genes were divided into 26 subgroups based on their evolutionary relationships and found to be distributed randomly on 46 chromosomes. RNA sequencing data and subsequent real-time quantitative PCR analysis of 12 differentially expressed R2R3-HhMYB genes showed HhMYB111r to be highly expressed under various abiotic stress conditions. Self-activation and subcellular localization results showed that the intact HhMYB111r had strong self-activation activity and located in both the nucleus and cytoplasm. Overexpression in Arabidopsis significantly improved salt tolerance, and silencing HhMYB111r reduced the tolerance of H. hamabo to salt stress, indicating that HhMYB111r positively regulates the salt stress response. In this first analysis of the R2R3-MYB gene family in H. hamabo, we identified a key salt stress response gene, HhMYB111r, enriching the understanding of MYB function and laying a foundation for exploring the abiotic stress response of plants.
海滨木槿（Hibiscus hamabo Sieb. et Zucc.）是一种具有出色抗逆性的半红树植物，在盐碱地生态修复中发挥着关键作用。它是研究抗逆机制的理想候选物种。尽管已经对海滨木槿中的MYB基因家族进行了初步表征，但该物种中R2R3-MYB基因的具体功能和作用机制尚未完全阐明。在本研究中，利用生物信息学方法在基因组水平上鉴定出190个R2R3-MYB基因。这些基因根据其进化关系被分为26个亚组，并发现随机分布在46条染色体上。对12个差异表达的R2R3-HhMYB基因的RNA测序数据及随后的实时定量PCR分析表明，HhMYB111r在各种非生物胁迫条件下均高表达。自激活和亚细胞定位结果表明，完整的HhMYB111r具有很强的自激活活性，且定位于细胞核和细胞质中。在拟南芥中过表达显著提高了耐盐性，而沉默HhMYB111r降低了海滨木槿对盐胁迫的耐受性，表明HhMYB111r正向调控盐胁迫反应。在对海滨木槿R2R3-MYB基因家族的首次分析中，我们鉴定出一个关键的盐胁迫响应基因HhMYB111r，丰富了对MYB功能的理解，并为探索植物的非生物胁迫反应奠定了基础。
