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。 因此，我们的研究结果可能会影响旨在生产更多木材，抵御干旱胁迫或提高光合能力的植物改造。 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或对植物激素生长素的响应。 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入和流出蛋白的不对称位置定向运输对生长素功能至关重要。 虽然生长素流出的控制越来越好地理解，生长素流入的控制知之甚少。 静脉图案似乎是足够复杂的静脉图案突变体的屏幕显示生长素运输和响应的新组件，与冗余的角色或效果太微妙，在经典的屏幕中检测。 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。我们建议剖析四个基因的作用- AUTOBAHN（ABN），FORKED 1（FKD 1），UNHINGED（UNH）和GRASSY（GSY）-通过突变鉴定。ABN突变体使叶脉高度紊乱，改变叶片的位置。 我们的数据表明，这些植物是有缺陷的生长素流入，因此代表了第一个突变，生长素流入叶的位置和静脉模式。 我们计划进行实验，以找出ABN产品，以及它如何影响生长素流入。 FKD 1基因产物是一种蛋白质，其结构域指示参与将生长素流出蛋白正确定位于细胞膜。 我们将测试这个想法。 最后，我们将确定和表征UNH和GSY的突变表型表明生长素运输或信号的作用。

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.