Key Laboratory of Southern Subtropical Plant Diversity, Fairy Lake Botanical Garden, Shenzhen & Chinese Academy of Science, Shenzhen, China.
Core Botanical Gardens/Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China.
PeerJ. 2022 Aug 9;10:e13603. doi: 10.7717/peerj.13603. eCollection 2022.
Heat shock factor (HSF) genes are essential in some of the basic developmental pathways in plants. Despite extensive studies on the structure, functional diversification, and evolution of HSF genes, their divergence history and gene duplication pattern remain unknown. To further illustrate the probable divergence patterns in these subfamilies, we analyzed the evolutionary history of HSF genes using phylogenetic reconstruction and genomic syntenic analyses, taking advantage of the increased sampling of genomic data from pteridophytes, gymnosperms and basal angiosperms. We identified a novel clade that includes HSFA2, HSFA6, HSFA7, and HSFA9 with a complex relationship, which is very likely due to orthologous or paralogous genes retained after frequent gene duplication events. We hypothesized that HSFA9 derives from HSFA2 through gene duplication in eudicots at the ancestral state, and then expanded in a lineage-specific way. Our findings indicate that HSFB3 and HSFB5 emerged before the divergence of ancestral angiosperms, but were lost in the most recent common ancestors of monocots. We also presumed that HSFC2 derives from HSFC1 in ancestral monocots. This work proposes that during the radiation of flowering plants, an era during which there was a differentiation of angiosperms, the size of the HSF gene family was also being adjusted with considerable sub- or neo-functionalization. The independent evolution of HSFs in eudicots and monocots, including lineage-specific gene duplication, gave rise to a new gene in ancestral eudicots and monocots, and lineage-specific gene loss in ancestral monocots. Our analyses provide essential insights for studying the evolutionary history of this multigene family.
热休克因子 (HSF) 基因在植物的一些基本发育途径中是必不可少的。尽管对 HSF 基因的结构、功能多样化和进化进行了广泛的研究，但它们的分化历史和基因复制模式仍然未知。为了进一步说明这些亚家族可能的分化模式，我们利用从蕨类植物、裸子植物和基干被子植物中增加的基因组数据采样，通过系统发育重建和基因组共线性分析来分析 HSF 基因的进化历史。我们确定了一个新的亚家族，其中包括 HSFA2、HSFA6、HSFA7 和 HSFA9，它们之间的关系非常复杂，这很可能是由于同源或旁系基因在频繁的基因复制事件后保留下来。我们假设 HSFA9 是通过在被子植物祖先状态下的基因复制从 HSFA2 衍生而来的，然后以谱系特异性的方式扩展。我们的研究结果表明，HSFB3 和 HSFB5 出现在祖先进化的被子植物分化之前，但在单子叶植物的最近共同祖先中丢失了。我们还推测 HSFC2 是从祖先进化的单子叶植物中的 HSFC1 衍生而来的。这项工作表明，在开花植物辐射期间，即被子植物分化的时期，HSF 基因家族的大小也在通过大量亚功能化或新功能化进行调整。在真双子叶植物和单子叶植物中 HSF 的独立进化，包括谱系特异性基因复制，导致了在祖先进化的真双子叶植物和单子叶植物中产生了一个新基因，而在祖先进化的单子叶植物中则发生了谱系特异性基因丢失。我们的分析为研究这个多基因家族的进化历史提供了重要的见解。
