Molecular Mechanisms of Brassinosteroid Action

[9728118]关于类固醇激素调节脊椎动物和昆虫基因表达的分子机制，我们已经知道了很多。相比之下，在高等植物中发现的促进生长的类固醇才刚刚开始被研究。油菜素内酯是一种植物类固醇激素，在低浓度（十亿分之一克）的情况下，会对拟南芥、玉米、大豆、水稻、土豆、萝卜、生菜、辣椒和橙子等多种植物的生长产生深远影响。在NSF之前的支持下，我们的实验室发现油菜素内酯可以提高植物茎的伸长并调节基因表达。美国国家科学基金会目前拨款的目的是研究油菜素类固醇调节基因的DNA序列，这些基因负责控制对这些植物类固醇激素的反应。由于油菜素内酯在结构上与动物类固醇激素相似，了解它们的活性在基础发育生物学中具有重要的潜在意义。鉴于油菜素内酯对作物的影响已被证实，对油菜素内酯作用的分子机制的深入了解也将具有农业潜力。

9728118 Clouse A great deal is known concerning the molecular mechanisms by which steroid hormones regulate gene expression in vertebrates and insects. In contrast, the growth-promoting steroids found in higher plants are only beginning to be studied. Brassinosteroids are plant steroid hormones that act at low concentrations (one billionth of a gram) to profoundly affect the growth of a wide range of plants including arabidopsis, corn, soybean, rice, potatoes, radish, lettuce, pepper and oranges. With previous NSF support, our laboratory showed that brassinosteroids enhanced the elongation of stems and regulated gene expression in plants. The objective of the current NSF grant is to study the DNA sequences in brassinosteroid regulated genes that are responsible for controlling the response to these plant steroid hormones. Because brassinosteroids are similar in structure to animal steroid hormones, understanding their activity has great potential importance in basic developmental biology. In view of the multitude of demonstrated effects brassinosteroids have on crops, a deeper understanding of the molecular mechanisms of brassinosteroid action would have agricultural potential as well.