A photo-responsive F-box protein FOF2 regulates floral initiation by promoting FLC expression in Arabidopsis
A photo-responsive F-box protein FOF2 regulates floral initiation by promoting FLC expression in Arabidopsis
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DOI：
10.1111/tpj.13607
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发表时间：
2017-09-01
期刊：
影响因子：
7.2
通讯作者：
Lin, Chentao
中科院分区：
文献类型：
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作者：
He, Reqing;Li, Xinmei;Lin, Chentao
花的形成受光照、温度、激素和发育状态等多种遗传途径的调控；然而，不同遗传途径之间相互作用的分子机制尚不完全清楚。在这里，我们发现光响应基因FOF2（开花2的F-box）负调控开花。FOF2编码一种假定的与ASK14特异性相互作用的F-box蛋白，其过表达导致在长日照和短日照条件下开花较晚。相反，表达FOF2的F-box结构域缺失突变体（FOF2DF）或FOF2和FOL1的双重功能缺失突变体（FOF2- like 1）的转基因植物呈现早开花表型。FOF2过表达系的晚花表型受到flc-3功能缺失突变的抑制。此外，FOF2 mRNA的表达受自主通路基因FCA的调控，FOF2在开花中的抑制作用可以通过春化来克服。有趣的是，FOF2的表达受光的调控。FOF2的蛋白水平在光照条件下积累，而在黑暗条件下通过26S蛋白酶体途径降解。我们的研究结果表明，在光条件和拟南芥自主开花促进途径之间可能存在机制联系。
Floral initiation is regulated by various genetic pathways in response to light, temperature, hormones and developmental status; however, the molecular mechanisms underlying the interactions between different genetic pathways are not fully understood. Here, we show that the photoresponsive gene FOF2 (F-box of flowering 2) negatively regulates flowering. FOF2 encodes a putative F-box protein that interacts specifically with ASK14, and its overexpression results in later flowering under both long-day and short-day photoperiods. Conversely, transgenic plants expressing the F-box domain deletion mutant of FOF2 (FOF2DF), or double loss of function mutant of FOF2 and FOL1 (FOF2-LIKE 1) present early flowering phenotypes. The late flowering phenotype of the FOF2 overexpression lines is suppressed by the flc-3 loss-of-function mutation. Furthermore, FOF2 mRNA expression is regulated by autonomous pathway gene FCA, and the repressive effect of FOF2 in flowering can be overcome by vernalization. Interestingly, FOF2 expression is regulated by light. The protein level of FOF2 accumulates in response to light, whereas it is degraded under dark conditions via the 26S proteasome pathway. Our findings suggest a possible mechanistic link between light conditions and the autonomous floral promotion pathway in Arabidopsis.