本论文于2017年11月29日在线发表于Plant Physiology，原文题目如下：

The transcription factor COL12 is a substrate of the COP1/SPA E3 ligase and regulates flowering time and plant architecture

在整个植物生命周期中，环境光线环境控制植物发育的许多方面。拟南芥中，光信号的关键抑制子是COP1/SPA E3泛素连接酶，它引起内源发育相关途径的许多调节子的降解，从而实现这种复杂的控制。这包括负责开花时间的光周期控制的CONSTANS（CO）转录因子。有16个类CONSTANS蛋白质，而它们的功能只是部分被研究。这里，我们发现14个COL蛋白在体外结合COP1和SPA1。我们随后关注COL12并显示COL12在体内结合COP1和SPA蛋白。 COL12蛋白在COP1依赖性的黑暗中降解，表明COL12是COP1/SPA泛素连接酶的底物。COL12的过表达通过降低FT的表达，特别在长日照条件下引起晚开花。这种表型在遗传上依赖于CO。与这一发现一致，COL12在体内与CO物理上相互作用，表明COL12通过抑制CO蛋白功能来抑制开花。COL12过表达并没有改变CO蛋白的稳定性。因此COL12可能抑制CO的活性，而不是CO的水平。 COL12的过表达也通过增加莲座叶分枝的数量和降低花序高度来影响植物结构。这些表型是不依赖CO的。因此，我们推测COL12通过依赖CO和不依赖CO的机制来影响植物发育。

The ambient light environment controls many aspects of plant development throughout a plant's life cycle. Such complex control is achieved because a key repressor of light signaling, the Arabidopsis COP1/SPA E3 ubiquitin ligase, causes the degradation of multiple regulators of endogenous developmental pathways. This includes the CONSTANS (CO) transcription factor which is responsible for photoperiodic control of flowering time. There are 16 CONSTANS-like proteins whose functions are only partly understood. Here, we show that 14 COL proteins bind COP1 and SPA1 in vitro. We subsequently focused on COL12 and show that COL12 binds COP1 and SPA proteins in vivo. The COL12 protein is degraded in darkness in a COP1-dependent fashion, indicating that COL12 is a substrate of the COP1/SPA ubiquitin ligase. Overexpression of COL12 causes late flowering specifically in long day conditions by decreasing the expression of FT. This phenotype is genetically dependent on CO. Consistent with this finding, COL12 physically interacts with CO in vivo, suggesting that COL12 represses flowering by inhibiting CO protein function. We show that COL12 overexpression did not alter CO protein stability. It is therefore likely that COL12 represses the activity of CO rather than CO levels. Overexpression of COL12 also affects plant architecture by increasing the number of rosette branches and reducing inflorescence height. These phenotypes are CO-independent. Hence, we suggest that COL12 affects plant development through CO-dependent and CO-independent mechanisms.

每日一词

ambient

英[ˈæmbiənt]

美[ˈæmbiənt]

adj. 环境; 周围的，包围着的; 产生轻松氛围的;

[例句]Another ambient temperature sensor is the vapor-filled bellows.

另一种空气温度传感器是充气波纹管。