Sakai H, Medrano L J, Meyerowitz E M
Division of Biology, California Institute of Technology, Pasadena 91125, USA.
Nature. 1995 Nov 9;378(6553):199-203. doi: 10.1038/378199a0.
The Arabidopsis gene SUPERMAN (SUP) is necessary for the proper spatial development of reproductive floral tissues. Recessive mutations cause extra stamens to form interior to the normal third whorl stamens, at the expense of fourth whorl carpel development. The mutant phenotype is associated with the ectopic expression of the B function genes, AP3 and PI, in the altered floral region, closer to the centre of the flower than in the wild type, and ap3 sup and pi sup double mutants exhibit a phenotype similar to ap3 and pi single mutants. These findings led to SUP being interpreted as an upstream negative regulator of the B function organ-identity genes, acting in the fourth whorl, to establish a boundary between stamen and carpel whorls. Here we show, using molecular cloning and analysis, that it is expressed in the third whorl and acts to maintain this boundary in developing flowers. The putative SUPERMAN protein contains one zinc-finger and a region resembling a basic leucine zipper motif, suggesting a function in transcriptional regulation.
拟南芥基因SUPERMAN（SUP）对于生殖花器官的正常空间发育是必需的。隐性突变会导致在正常第三轮雄蕊内部形成额外的雄蕊，代价是第四轮心皮发育受损。突变表型与B功能基因AP3和PI在改变的花区域中的异位表达相关，该区域比野生型更靠近花的中心，并且ap3 sup和pi sup双突变体表现出与ap3和pi单突变体相似的表型。这些发现导致SUP被解释为B功能器官特征基因的上游负调控因子，在第四轮中起作用，以在雄蕊和心皮轮之间建立边界。在这里，我们通过分子克隆和分析表明，它在第三轮中表达，并在发育中的花中维持这个边界。推测的SUPERMAN蛋白包含一个锌指和一个类似于碱性亮氨酸拉链基序的区域，提示其在转录调控中的功能。
