Xu Ping, Guo Qinwei, Pang Xin, Zhang Peng, Kong Dejuan, Liu Jia
Department of Tea Science, Zhejiang University, Hangzhou 310058, China.
Quzhou Academy of Agricultural Sciences, Quzhou 324000, Zhejiang, China.
Plants (Basel). 2020 Mar 2;9(3):311. doi: 10.3390/plants9030311.
Heat shock transcription factor (Hsf) is one of key regulators in plant abotic stress response. Although the Hsf gene family has been identified from several plant species, original and evolution relationship have been fragmented. In addition, tea, an important crop, genome sequences have been completed and function of the Hsf family genes in response to abiotic stresses was not illuminated. In this study, a total of 4208 Hsf proteins were identified within 163 plant species from green algae () to angiosperm (monocots and dicots), which were distributed unevenly into each of plant species tested. The result indicated that Hsf originated during the early evolutionary history of chlorophytae algae and genome-wide genetic varies had occurred during the course of evolution in plant species. Phylogenetic classification of Hsf genes from the representative nine plant species into ten subfamilies, each of which contained members from different plant species, imply that gene duplication had occurred during the course of evolution. In addition, based on RNA-seq data, the member of the Hsfs showed different expression levels in the different organs and at the different developmental stages in tea. Expression patterns also showed clear differences among species, indicating that regulation of Hsf genes expression varied between organs in a species-specific manner. Furthermore, expression of most Hsfs in response to drought, cold and salt stresses, imply a possible positive regulatory role under abiotic stresses. Expression profiles of nineteen Hsf genes in response to heat stress were also analyzed by quantitative real-time RT-PCR. Several stress-responsive Hsf genes were highly regulated by heat stress treatment. In conclusion, these results lay a solid foundation for us to elucidate the evolutionary origin of plant Hsfs and Hsf functions in tea response to abiotic stresses in the future.
热激转录因子（Hsf）是植物非生物胁迫响应中的关键调控因子之一。尽管已从多种植物中鉴定出Hsf基因家族，但其起源和进化关系仍不完整。此外，重要作物茶树的基因组序列已完成，而Hsf家族基因在响应非生物胁迫方面的功能尚未阐明。在本研究中，从绿藻到被子植物（单子叶植物和双子叶植物）的163种植物中总共鉴定出4208个Hsf蛋白，它们在每个受试植物物种中的分布并不均匀。结果表明，Hsf起源于绿藻的早期进化历史，并且在植物物种进化过程中发生了全基因组遗传变异。来自代表性9种植物的Hsf基因被系统发育分类为10个亚家族，每个亚家族都包含来自不同植物物种的成员，这意味着在进化过程中发生了基因复制。此外，基于RNA测序数据，Hsf成员在茶树的不同器官和不同发育阶段表现出不同的表达水平。不同物种之间的表达模式也存在明显差异，表明Hsf基因表达的调控在不同器官之间以物种特异性方式变化。此外，大多数Hsf在响应干旱、寒冷和盐胁迫时的表达，暗示其在非生物胁迫下可能具有正向调控作用。还通过定量实时RT-PCR分析了19个Hsf基因对热胁迫的响应表达谱。几个胁迫响应性Hsf基因受到热胁迫处理的高度调控。总之，这些结果为我们未来阐明植物Hsf的进化起源以及Hsf在茶树响应非生物胁迫中的功能奠定了坚实基础。
