Auxin Biosynthesis and Signaling Mechanisms.

生长素生物合成和信号传导机制。

• 批准号: 6673644
• 负责人: YUNDE ZHAO
• 金额: $ 29.49万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6673644
• 关键词: Arabidopsis; biological signal transduction; chemical genetics; gene expression; gene mutation; genetic screening; green fluorescent proteins; hormone biosynthesis; in situ hybridization; indoleacetate; mass spectrometry; microarray technology; molecular cloning; northern blottings; oxygenases; phytohormones; plant genetics; plant growth /development; plant proteins; polymerase chain reaction; protein purification; proteomics; regulatory gene; western blottings; yeast two hybrid system

DESCRIPTION (provided by applicant): Auxin was the first plant hormone ever identified, and it has been implicated in almost every aspect of plant growth and development. Auxin has been studied for over a century, but the molecular mechanisms that promote its biological activities remain poorly understood. It is not even clear how auxin is produced by plants, let alone how that process is regulated by developmental and environmental signals. This lack of knowledge of auxin biosynthesis further clouds our understanding of auxin-mediated signal transduction. The major objective of the work proposed herein is to isolate and characterize previously unidentified components of auxin biosynthesis and signaling. We have characterized a dominant auxin overproduction mutant, yucca, and this provides us with a unique opportunity to design new strategies to examine auxin-related processes. YUCCA is a member of the flavin-containing monooxygenase (FMO) superfamily, and it catalyzes a rate-limiting step in auxin biosynthesis. Additional components of auxin biosynthesis and signaling can be isolated from genetic screens for yucca suppressors and yucca-like mutants. Biochemical approaches can be utilized to identify YUCCA associated proteins. The first specific aim of this proposal is to characterize yucca suppressors. Second, we propose to further define the roles of the YUCCA gene family by using reverse genetics. Third, we will use biochemical approaches to examine YUCCA associated proteins. Fourth, we will further characterize yucca-like mutants that we have already identified. Fifth and finally, we propose to use chemical genetics in our characterization of sir1, a mutant insensitive to sirtinol that shows constitutive activation of known auxin-inducible genes. These studies are multi-disciplinary in nature and should yield significant new insights into the mechanisms of auxin regulated processes and these processes are of paramount importance to plant biology. A clear understanding of auxin's role in plant growth and development will ultimately have significant agricultural impact. Finally, the proposed study will augment our understanding of complex signaling mechanisms in other eukaryotes, particularly in the area of tryptophan homeostasis, which is essential to most organisms, including humans.

描述（申请人提供）：生长素是第一个被鉴定的植物激素，它几乎涉及植物生长和发育的各个方面。生长素已经被研究了世纪，但促进其生物活性的分子机制仍然知之甚少。目前还不清楚植物是如何产生生长素的，更不用说这个过程是如何受到发育和环境信号的调节的了。这种缺乏知识的生长素生物合成进一步云我们的理解生长素介导的信号转导。本文提出的工作的主要目标是分离和表征生长素生物合成和信号传导的先前未鉴定的组分。我们的特点是一个占主导地位的生长素生产过剩的突变体，丝兰，这为我们提供了一个独特的机会，设计新的策略来研究生长素相关的过程。YUCCA是含黄素单加氧酶（FMO）超家族的成员，它催化生长素生物合成的限速步骤。生长素生物合成和信号传导的其他组分可以从丝兰抑制子和丝兰样突变体的遗传筛选中分离。生物化学方法可用于鉴定YUCCA相关蛋白。该提案的第一个具体目标是描述丝兰抑制因子的特征。其次，我们建议通过反向遗传学进一步确定YUCCA基因家族的作用。第三，我们将使用生物化学方法来检测YUCCA相关蛋白。第四，我们将进一步描述我们已经确定的丝兰样突变体。第五，最后，我们建议使用化学遗传学在我们的sir1，一个突变体不敏感的sirtinol，已知的生长素诱导基因的组成型激活的特性。这些研究是多学科的性质，并应产生显着的新的见解生长素调节过程的机制，这些过程是至关重要的植物生物学。对生长素在植物生长发育中的作用有一个清楚的认识，最终将对农业产生重大影响。最后，拟议的研究将增加我们对其他真核生物中复杂信号机制的理解，特别是在色氨酸稳态领域，这对包括人类在内的大多数生物体至关重要。