Regulation of Auxin Fluxes Required for Phototropic Growth

向光性生长所需的生长素通量的调节

基本信息

批准号：
BB/J016047/1
负责人：
John Christie
金额：
$ 56.23万
依托单位：
University of Glasgow
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2013
资助国家：
英国
起止时间：
2013 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=BB%2FJ016047%2F1
关键词：
Regulation Auxin Fluxes Required Phototropic

项目摘要

Plants depend on sunlight for photosynthesis and adapt their growth to optimise light capture. Phototropism, the reorientation of growth towards light, represents one of these important adaptive responses. Modern-day studies of phototropism began with experiments in monocotyledonous grasses by Charles Darwin and led ultimately to the discovery of the plant growth hormone auxin, establishing the concept that light perception at the shoot apex triggers differential bending in the tissues below. In the past two decades, molecular-genetic analysis in the model flowering plant Arabidopsis thaliana has identified the principle photoreceptor for phototropism, phot1, as well as the major auxin transporters. Despite extensive efforts, however, how the photoreceptor regulates auxin transport so as to establish differential growth is poorly understood, as is whether this process is conserved between monocots and dicots. Therefore, the key aim of this proposal is to identify and characterise the signalling events associated with establishing auxin fluxes required for phototropic growth. By adopting a revised approach to study phototropism in Arabidopsis in the absence of developmental events that are typically associated with seedling photomorphogenesis, we have shown that the proximity of light perception and differential growth is conserved between monocots and dicots: in both plant types, differential growth is a consequence of lateral auxin movements across the shoot apex. Moreover, we have identified two auxin transporter proteins, PIN-FORMED (PIN3) and ATP-BINDING CASSETTE B19 (ABCB19), that contribute to these movements, the latter of which is directly regulated by phot1 and serves to prime lateral auxin fluxes in the shoot apex. These findings uncover new mechanistic information of the events coupling photoreception and auxin signalling, two processes that are critical for shaping plant growth. Hence, this proposal is focused on further characterising the molecular processes involved in establishing phototropic growth. Given the fundamental importance of both light and auxin in controlling plant development, these insights should ultimately provide new strategies to manipulate plant growth for agronomic gain.

植物依靠阳光进行光合作用并调整其生长以优化光捕获。向光性，即生长向光的重新定向，代表了这些重要的适应性反应之一。现代向光性的研究始于查尔斯·达尔文在单子叶草上的实验，并最终发现了植物生长激素生长素，建立了茎尖的光感知触发下面组织的差异弯曲的概念。在过去的二十年中，模型开花植物拟南芥的分子遗传学分析已经确定了向光性的主要光感受器 phot1 以及主要的生长素转运蛋白。然而，尽管付出了广泛的努力，但人们对光感受器如何调节生长素运输以建立差异生长以及这一过程在单子叶植物和双子叶植物之间是否保守的情况知之甚少。因此，该提案的主要目的是识别和表征与建立向光性生长所需的生长素通量相关的信号事件。通过采用修订的方法在不存在通常与幼苗光形态建成相关的发育事件的情况下研究拟南芥的向光性，我们发现单子叶植物和双子叶植物之间的光感知和差异生长的接近性是保守的：在两种植物类型中，差异生长是生长素横向运动穿过芽尖的结果。此外，我们还鉴定了两种植物生长素转运蛋白，PIN-FORMED (PIN3) 和 ATP-BINDING CASSETTE B19 (ABCB19)，它们有助于这些运动，后者直接受 phot1 调节，并用于启动植物生长素的侧向通量。拍摄顶点。这些发现揭示了光感受和生长素信号传导耦合事件的新机制信息，这两个过程对于塑造植物生长至关重要。因此，该提案的重点是进一步表征建立向光性生长所涉及的分子过程。鉴于光和生长素在控制植物发育中的根本重要性，这些见解最终应提供新的策略来操纵植物生长以获得农艺收益。