Gentian FLOWERING LOCUS T orthologs regulate phase transitions: floral induction and endodormancy release

第一作者：Hideyuki Takahashi

第一单位：日本東海大学

第一通讯：Kimiko Itoh

 Abstarct 

背景回顾：Perennial plants undergo a dormant period in addition to the growth and flowering phases that are commonly observed in annuals and perennials. Consequently, the regulation of these phase transitions in perennials is believed to be complicated. Previous studies have proposed that orthologs of FLOWERING LOCUS T (FT) regulate not only floral initiation but also dormancy. 

一年生和多年生植物中均会观察到的生长阶段和开花阶段外，但是对于多年生植物来说，其还会经历一个休眠期。因此，多年生植物中这些阶段的调控被认为是非常复杂的。先前的研究表明，FT的直系同源基因不仅调节花的起始，而且还调节休眠。

主要研究：We, therefore, investigated the involvement of FT orthologs (GtFT1 and GtFT2) during the phase transitions of the herbaceous perennial gentian (Gentiana triflora). 

因此，本文中作者研究了FT直系同源物GtFT1和GtFT2在多年生草本植物三花龙胆（Gentiana triflora）不同发育阶段转变过程中的作用。

结果1-GtTF1和GtTF2的功能：Analysis of seasonal fluctuations in the expression of these genes revealed that GtFT1 expression increased prior to budbreak and flowering, whereas GtFT2 expression was induced by chilling temperatures with the highest expression occurring when endodormancy was released. The expression of FT-related transcription factors, reportedly involved in flowering, also fluctuated during each phase transition. These results suggested the involvement of GtFT1 in budbreak and floral induction and GtFT2 in dormancy regulation, implying that the two gentian FT orthologs activated a different set of transcription factors. 

对于基因在不同季节的波动表达分析表明，GtFT1的表达在芽萌发和开花之前就开始增加，而GtFT2的表达则是受到低温所诱导的，在内休眠接触时表达量最高。以往报道中与开花有关的FT相关转录因子，在不同发育阶段转变期间的表达也会出现波动。这些结果表明，GtFT1参与了芽萌发和成花诱导，而GtFT2则参与了休眠的调节，这表明两个三花龙胆FT同源基因激活了不同的转录因子。

结果2-Gtft2突变：Gentian ft2 mutants generated by CRISPR/Cas9-mediated genome editing had a lower frequency of budbreak and budbreak delay in overwintering buds caused by an incomplete endodormancy release. 

作者通过CRISPR/Cas9介导的基因组编辑技术，获得了三花龙胆ft2的突变体，其越冬后的芽具有较低的芽萌发率和芽萌发延迟率，该表型是由于不完全的内休眠解除而导致的。

结果3-GtFT2下游：Our results highlighted that the gentian orthologs of FRUITFULL (GtFUL) and SHORT VEGETATIVE PHASE-like 1 (GtSVP-L1) act downstream of GtFT2, probably to prevent untimely budbreak during ecodormancy. 

另外，本文的研究结果进一步表明，三花龙胆中GtFUL和GtSVP-L1基因在GtFT2的下游发挥作用，可能是为了防止在生态休眠期间出现不合时宜的芽萌发。这些结果表明，每一个龙胆FT同源基因通过对内源性或外界环境的不同响应，调节不同的发育阶段转变，导致其具有能够诱导不同下游基因表达的能力。

结论：These results suggest that each gentian FT ortholog regulates a different phase transition by having variable responses to endogenous or environmental cues, leading to their ability to induce the expression of distinct downstream genes.

这些结果表明，每一个龙胆FT同源基因通过对内源性或外界环境的不同响应，调节不同的发育阶段转变，导致其具有能够诱导不同下游基因表达的能力。

doi: https://doi.org/10.1093/plphys/kiac007

Journal: Plant Physiology

​Published date: January 13, 2022