Understanding the molecular mechanism of vein formation in Arabidopsis

我们的研究致力于了解控制静脉形成的分子机制。维管系统是植物结构和功能的基础，为水、光合产物、必需营养素、病原体和信号化合物提供骨架和有效的运输途径。事实上，由于改善了光合作用细胞的水分输送，脉的密度是不同植物进化过程中光合效率的关键预测因子。因此，我们的研究结果可以提供信息，并允许植物修改旨在提高光合能力或抵御干旱胁迫。被确定为对叶脉形成重要的因素主要涉及植物激素生长素的运输。生长素在植物的许多发育过程中起重要作用，包括胚极性、根组织、分支根和叶的位置以及对重力和光的响应。在所有的过程中，生长素通过细胞膜上生长素流出蛋白的不对称位置定向运输对生长素功能至关重要。静脉图案似乎是足够复杂的静脉图案突变体的屏幕显示新的生长素运输组件与冗余的角色或效果太微妙，在经典的屏幕根或胚胎缺陷检测。因此，除了提供一个更好的了解维管形成，我们的工作将揭示分子机制控制生长素的定位和活性在整个植物发育。我们已经发现了两个基因，FORKED 1和UNHINGED是重要的生长素外排蛋白在发育细胞中的不对称放置。我们将更精确地定义这些基因的蛋白质产物是如何工作的，通过确定它们在细胞中的作用位置，它们与什么蛋白质形成复合物以及它们的表达，定位和伙伴关系是如何调节的。同时，我们将鉴定出对协调叶脉图案与叶子形状和控制叶子内叶脉密度重要的新基因。

Our research works towards understanding the molecular mechanisms controlling vein formation. The vascular system is fundamental to plant structure and function, providing a skeleton and efficient transport routes for water, photosynthates, essential nutrients, pathogens and signaling compounds. In fact, because of improved water delivery to photosynthesizing cells, the density of veins is a key predictor of photosynthetic efficiency within diverse plants through evolutionary time. Thus, our findings may inform and allow plant modifications designed to improve photosynthetic capacity or withstand drought stress. The factors identified as being important to vein formation are primarily involved in transport of the plant hormone, auxin. Auxin is fundamental to a huge number of plant developmental processes, including embryo polarity, root organization, placement of branch roots and leaves and response to gravity and light. In all processes directional auxin transport through asymmetric placement of auxin efflux proteins on cell membranes is critical to auxin function. Vein pattern seems to be sufficiently complex that screens for vein pattern mutants reveal novel auxin transport components with either redundant roles or effects too subtle to be detected in classical screens for root or embryonic defects. Thus, beyond providing a better understanding of vascular formation, our work will reveal molecular mechanisms controlling auxin localization and activity throughout plant development. We have found two genes, FORKED1 and UNHINGED that are important for asymmetric placement of auxin efflux proteins in developing cells. We will define more precisely how the protein products of these genes work though establishing where they act in the cell, what proteins they form complexes with and how their expression, localization and partnerships are regulated. As well, we will identify new genes important to coordinating vein pattern with leaf shape and controlling the density of veins within the leaf.