Hormonal control of flowering: Molecular mechanisms of hormone-receptor action

关于介导从营养到生殖习性的发育转换的受体事件知之甚少。我们在拟南芥中进行了修饰突变，并分离出作为时间调节因子的油菜素受体BRI1。进一步的努力建立了其修饰活性的遗传节点，并且发现有效的花阻遏物FLC是BRI1的分子靶标。由于BRI1编码一种受体激酶，我们对导致花时遗传程序的膜蛋白的生化机制很感兴趣。一个单独分离的突变分析令人惊讶地导致我们发现另一个受体激酶家族参与开花时间，这里称为RCF基因座。遗传和分子分析暗示这些受体在赤霉素信号。我们认为，它的广泛兴趣的特点，RCF蛋白作为“失踪”的激素受体赤霉素。总的来说，我们的建议工作的花的过渡的受体介导的机制将打开一个知之甚少的生物学现象的理解。因此，这些努力应该导致突破性的低估激素控制的时间过程。

Little is known regarding hormone-receptor events that mediated the developmental switch from the vegetative to reproductive habit. We conducted a modifier mutagenesis in Arabidopsis and isolated the brassinolide receptor BRI1 as a timing regulator. Further efforts established the genetic node of its modifying activity, and the potent floral repressor FLC was found to be the molecular target of BRI1. As BRI1 encodes a receptor kinase, we are intrigued as to the biochemical mechanism from a membrane protein that leads to the floral-timing genetic program. Analysis of a separately isolated mutation surprisingly lead to our discovery of another receptorkinase family that participates in floral timing, termed here the RCF loci. Genetic and molecular analyses implicate these receptors in gibberellin signaling. We consider it of broad interest to characterize the RCF proteins as the "missing" hormone receptor for gibberellin. Collectively, our proposal to work on hormone-receptor mediation of the floral transition will open up mechanistic understandings of a poorly understood biological phenomenon. As such, these efforts should lead to ground-breaking understating of hormonal control of a timing process.