Abstract：
Heat shock transcription factors (Hsfs) play multifaceted roles in plant growth, development, and responses to environmental factors. However, their involvement in seed dormancy and germination processes has remained elusive. In this study, we identified a wheat class B Hsf gene, TaHsf-7A, with higher expression in strong-dormancy varieties compared to weak-dormancy varieties during seed imbibition. Specifically, TaHsf-7A expression increased during seed dormancy establishment and subsequently declined during dormancy release. Through the identification of a 1-bp insertion (ins)/deletion (del) variation in the coding region of TaHsf-7A among wheat varieties with different dormancy levels, we developed a CAPS marker, Hsf-7A-1319, resulting in two allelic variations: Hsf-7A-1319-ins and Hsf-7A-1319-del. Notably, the allele Hsf-7A-1319-ins correlated with a reduced seed germination rate and elevated dormancy levels, while Hsf-7A-1319-del exhibited the opposite trend across 175 wheat varieties. The association of TaHsf-7A allelic status with seed dormancy and germination levels was confirmed in various genetically modified species, including Arabidopsis, rice, and wheat. Results from the dual luciferase assay demonstrated notable variations in transcriptional activity among transformants harboring distinct TaHsf-7A alleles. Furthermore, the levels of abscisic acid (ABA) and gibberellin (GA), along with the expression levels of ABA and GA biosynthesis genes, showed significant differences between transgenic rice lines carrying different alleles of TaHsf-7A. These findings represent a significant step towards a comprehensive understanding of TaHsf-7A\'s involvement in the dormancy and germination processes of wheat seeds.
摘要：
热激转录因子（Hsfs）在植物生长中起着多方面的作用，发展,以及对环境因素的反应。然而,他们参与种子休眠和发芽过程仍然难以捉摸。在这项研究中,我们鉴定出小麦B类Hsf基因,TaHsf-7A,在种子吸胀过程中，与弱休眠品种相比，强休眠品种中的表达更高。具体来说,TaHsf-7A表达在种子休眠建立期间增加，随后在休眠释放期间下降。通过在具有不同休眠水平的小麦品种之间TaHsf-7A编码区的1-bp插入（ins）/缺失（del）变异的鉴定，我们开发了一个CAPS标记，Hsf-7A-1319,导致两个等位基因变异:Hsf-7A-1319-ins和Hsf-7A-1319-del。值得注意的是,等位基因Hsf-7A-1319-ins与种子发芽率降低和休眠水平升高相关，而Hsf-7A-1319-del在175个小麦品种中表现出相反的趋势。在各种转基因物种中证实了TaHsf-7A等位基因状态与种子休眠和发芽水平的关联，包括拟南芥,大米,和小麦。来自双荧光素酶测定的结果证明在具有不同TaHsf-7A等位基因的转化体之间转录活性的显著变化。此外，脱落酸（ABA）和赤霉素（GA）的水平，随着ABA和GA生物合成基因的表达水平，在携带不同TaHsf-7A等位基因的转基因水稻品系之间显示出显着差异。这些发现代表了全面了解TaHsf-7A参与小麦种子休眠和发芽过程的重要一步。
