ABR: Genes controlling Fruit development in Arabidopsis

果实可以说是最复杂的植物器官，在种子发育时起到保护作用，然后在成熟时传播。来自不同植物物种的果实有各种各样的形状和大小，直到最近才确定了一些水果的基因。 拟南芥果实的子房由三个主要区域组成：来自子房壁的阀，在果实成熟时阀分离后保留的结构，以及在阀/replum边界处形成的阀边缘。 气门瓣缘是种子传播所必需的，由两个主要的模式要素组成。 第一层是细胞分离层，其中细胞的分离允许阀在种子传播过程中从隔膜分离。 瓣叶边缘的第二个组成部分是木质层，也被认为在果实成熟时促进种子传播。 瓣膜边缘的形成需要SHATTERPROOF MADS盒转录因子以及INDEHISCENT和ALCATRAZ碱性螺旋-环-螺旋型转录因子的活性。 FRUITFULLMADS盒转录因子通过负调节瓣膜边缘身份基因在很大程度上指定瓣膜。 类似地，REPLUMLESS同源结构域转录因子在很大程度上通过负调节瓣膜边缘身份基因来指定replum。 虽然我们现在已经掌握了拟南芥果实的主要调控因子，但我们对果实中特定细胞类型是如何被指定的仍然知之甚少。 我们提出的研究的一个主要重点是解剖级联的基因活性，导致水果发育过程中的特定细胞类型的分化。 我们建议采取多管齐下的方法来实现这些目标。 我们将通过对现有突变体进行增强子和抑制子筛选来继续我们的遗传研究，长期目标是克隆相应的基因。 我们将进行微阵列实验，以确定水果图案基因的目标。 我们将描述植物激素在指定果实图案和细胞分化中的作用。 总之，这些和其他拟议的研究将使我们开始解剖级联的基因活性，导致细胞分化在水果的发展。

The fruit is arguably the most complex plant organ and serves to protect the seeds as they develop and then disperse them at maturity. Fruits from diverse plant species come in a wide array of shapes and sizes, and only recently have a number of the genes that pattern the fruit been identified. The ovary of the Arabidopsis fruit consists of three main regions: the valves, which are derived from the ovary walls, the replum, which is the structure that remains after the valves have detached at fruit maturity, and the valve margins that form at the valve/replum boundaries. The valve margin is essential for seed dispersal and consists of two main pattern elements. The first is a cell separation layer, where separation of cells allows the valves to detach from the replum during the seed dispersal process. The second element of the valve margin is the lignified layer that is also proposed to promote seed dispersal at fruit maturity. Valve margin formation requires the activities of the SHATTERPROOF MADS-box transcription factors as well as the INDEHISCENT and ALCATRAZ basic helix-loop-helix type transcription factors. The FRUITFULL MADS-box transcription factor specifies the valves in large part by negatively regulating the valve margin identity genes. Similarly, the REPLUMLESS homeodomain transcription factor specifies the replum in large part by negatively regulating the valve margin identity genes. Although we now have a handle on the major regulators that pattern the Arabidopsis fruit, we still know relatively little about how specific cell types within fruits are specified. A major focus of our proposed studies is to dissect the cascade of gene activity that leads to differentiation of specific cell types during fruit development. We propose a multi-pronged approach to achieve these goals. We will continue our genetic studies by performing enhancer and suppressor screens of existing mutants with the longer-term goal of cloning the corresponding genes. We will perform microarrray experiments to identify targets of the fruit patterning genes. We will characterize the role of plant hormones in specifying fruit patterning and cellular differentiation. Together, these and other proposed studies will allow us to begin to dissect the cascade of gene activity that leads to cellular differentiation during fruit development.