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

关于激素受体事件介导了从植物习性到生殖习性的发育转变，我们知之甚少。我们对拟南芥进行了修饰体诱变，并分离出油菜素内酯受体BRI1作为时序调节因子。进一步的研究确定了其修饰活性的遗传节点，并发现了有效的花抑制因子FLC是BRI1的分子靶点。由于BRI1编码受体激酶，我们对膜蛋白导致开花时间遗传程序的生化机制很感兴趣。对一个单独分离的突变的分析令人惊讶地导致我们发现了另一个参与花计时的受体激酶家族，这里称为RCF位点。遗传和分子分析暗示这些受体参与赤霉素信号传导。我们认为将RCF蛋白描述为赤霉素“缺失”的激素受体具有广泛的意义。总的来说，我们提出的关于激素受体介导花过渡的工作将打开对一个知之甚少的生物学现象的机制理解。因此，这些努力应该会导致突破性地低估激素对时间过程的控制。

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.