Divergent roles of FT-like 9 in flowering transition under different day lengths in Brachypodium distachyon
Divergent roles of FT-like 9 in flowering transition under different day lengths in Brachypodium distachyon
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FT-like 9在不同日长下短柄草开花转变中的不同作用
DOI：
10.1038/s41467-019-08785-y
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发表时间：
2019-02-18
影响因子：
16.6
通讯作者：
Wu, Liang
中科院分区：
文献类型：
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作者：
Qin, Zhengrui;Bai, Yuxue;Wu, Liang
开花植物生殖转换的时间是由环境因素精确调节的。兼性长日照植物，包括拟南芥和温带禾本科植物，在长日照条件下（LD）触发快速开花，在短日照条件下（SD）延迟开花。在这里，我们的特点是SD诱导的FLOWERLOCUS T的直系同源物，FT样9（FTL 9），促进开花的SD，但抑制开花的LD在短柄草二穗草。与光周期诱导的FT 1一样，FTL 9也能与FD 1相互作用形成开花激活复合物（FAC），但FTL 9-FAC的成花启动效率远低于FT 1-FAC，因此当FT 1不表达时，FTL 9对促进花的转变起正作用，而当FT 1大量积累时，FTL 9对促进花的转变起负显性作用。我们还发现CONSTANS 1（CO 1）除了刺激FT 1以增强LD下的加速开花外，还可以抑制FTL 9。我们对FTL 9在不同光长环境下的拮抗功能的研究结果将有助于理解FT在植物光周期开花的微调调节中的多方面作用。
Timing of reproductive transition is precisely modulated by environmental cues in flowering plants. Facultative long-day plants, including Arabidopsis and temperate grasses, trigger rapid flowering in long-day conditions (LDs) and delay flowering under short-day conditions (SDs). Here, we characterize a SD-induced FLOWERING LOCUS T ortholog, FT-like 9 (FTL9), that promotes flowering in SDs but inhibits flowering in LDs in Brachypodium distachyon. Mechanistically, like photoperiod-inductive FT1, FTL9 can interact with FD1 to form a flowering activation complex (FAC), but the floral initiation efficiency of FTL9-FAC is much lower than that of FT1-FAC, thereby resulting in a positive role for FTL9 in promoting floral transition when FT1 is not expressed, but a dominant-negative role when FT1 accumulates significantly. We also find that CONSTANS 1 (CO1) can suppress FTL9 in addition to stimulate FT1 to enhance accelerated flowering under LDs. Our findings on the antagonistic functions of FTL9 under different day-length environments will contribute to understanding the multifaceted roles of FT in fine-tune modulation of photoperiodic flowering in plants.