The molecular mechanism of vien patterning

我们的工作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、光合作用、必需营养物质、病原体和信号化合物提供骨架和有效的运输途径。因此，我们的发现可能会影响植物改造设计，以生产更多的木材，抵御干旱胁迫，或提高光合能力。被认为对静脉形成很重要的因素主要涉及植物激素生长素的运输或应答。生长素是许多植物发育过程的基础，包括胚胎极性，根组织，分枝根和叶的位置以及对重力和光的响应。在所有的过程中，生长素定向运输通过不对称放置生长素流入和流出的蛋白质在细胞膜上是生长素功能的关键。虽然对生长素外排的控制越来越了解，但对生长素内流的控制知之甚少。静脉模式似乎非常复杂，静脉模式突变体的筛选揭示了生长素运输和反应中的新成分，这些成分要么是冗余的作用，要么是在经典筛选中无法检测到的微妙影响。因此，除了更好地理解维管形成，我们的工作将揭示在植物发育过程中控制生长素定位和活性的分子机制。我们建议剖析四个基因- AUTOBAHN (ABN), FORKED1 (FKD1), unched （UNH）和GRASSY (GSY) -通过突变鉴定的作用。ABN突变株的叶脉高度紊乱，叶片位置发生改变。我们的数据表明，这些植物在生长素流入方面存在缺陷，因此代表了第一个将生长素流入与叶片位置和叶脉模式联系起来的突变。我们计划进行实验，找出ABN生产的产品，以及它是如何影响生长素流入的。FKD1基因产物是一种蛋白质，其结构域指示参与生长素外排蛋白在细胞膜上的适当定位。我们将测试这个想法。最后，我们将鉴定和表征UNH和GSY，其突变表型表明在生长素运输或信号传导中起作用。

Our work strives to understand 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. Thus, our findings may impact plant modifications designed to produce more wood, withstand drought stress, or improve photosynthetic capacity. The factors identified as being important to vein formation are primarily involved in transport of or response to 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 influx and efflux proteins on cell membranes is critical to auxin function. While control of auxin efflux is increasingly well understood, little is known about the control of auxin influx. Vein pattern seems to be sufficiently complex that screens for vein pattern mutants reveal novel components in auxin transport and response, with either redundant roles or effects too subtle to be detected in classical screens. Thus, beyond providing a better understanding of vascular formation, our work will reveal molecular mechanisms controlling auxin localization and activity throughout plant development. We propose to dissect the role of four genes - AUTOBAHN (ABN), FORKED1 (FKD1), UNHINGED (UNH) and GRASSY (GSY) - identified by mutation. Plants mutant in ABN make highly disordered veins and alter placement of leaves. Our data suggest that these plants are defective in auxin influx, and thus represent the first mutation that links auxin influx to leaf position and vein pattern. We plan experiments to find out what product ABN makes, and how it influences auxin influx. The FKD1 gene product is a protein with a domain indicative of involvement in properly localizing the auxin efflux protein to the cell membrane. We will test this idea. Finally, we will identify and characterize both UNH and GSY whose mutant phenotypes suggest a role in auxin transport or signaling.