Auxin Biosynthesis and Signaling Mechanisms

生长素生物合成和信号传导机制

• 批准号: 8037168
• 负责人: YUNDE ZHAO
• 金额: $ 31.48万
• 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 2013-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8037168
• 关键词: Address; Agriculture; Alleles; Anabolism; Arabidopsis; Auxins; Biochemical; Biological; Biology; Blood Vessels; Cells; Complex; Data; Defect; Development; Developmental Process; Dissection; Embryonic Development; Enhancers; Enzymes; Eukaryota; Family; Flavins; Flowers; Foundations; Gene Family; Genes; Genetic; Genetic Screening; Goals; Grant; Growth; Health; Homologous Gene; Human; Hypocotyl; Laboratories; Link; Mediating; Mixed Function Oxygenases; Molecular; Molecular Analysis; Molecular Genetics; Organ; Organism; Organogenesis; Pathway interactions; Pattern; Phenotype; Phosphorylation; Phosphotransferases; Phototropism; Plant Growth Regulators; Plant Model; Plant Roots; Plants; Play; Protein Family; Protein Kinase; Proteins; Regulation; Research; Resistance; Role; Seedling; Signal Transduction; Structure; Time; United States National Institutes of Health; Work; base; indoleacetic acid; insight; mutant; novel; plant growth/development; programs; research study; response; success; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): Auxin is an essential regulator for almost every aspect of plant growth and development. The general goal of this proposal is to elucidate the molecular mechanisms by which auxin regulates plant organogenesis and other developmental processes. During the last grant period, we demonstrated that the YUCCA (YUC) flavin monooxygenases play an essential role in auxin biosynthesis and various developmental processes including embryogenesis, seedling growth, vascular patterning, and floral development. Previous genetic studies on auxin signaling were centered on analysis of mutants resistant to exogenous auxin. Our understanding of auxin biosynthesis allowed us to elucidate the molecular mechanisms of auxin action in plant development from a completely different perspective. We identified npy1 (naked pins in yuc mutants) from a genetic screen for enhancers of the yuc1 yuc4 double mutants that are partially auxin deficient. The npy1 yuc1 yuc4 triple mutants developed pin-like inflorescences and failed to form any flowers, a hallmark phenotype caused by defects in auxin pathways. NPY1 belongs to a large family and is homologous to non-phototropic hypocotyl 3 (NPH3), a BTB protein regulating phototropism along with the AGC kinase PHOT1. NPY1 works with PID, a PHOT1 homolog, to regulate auxin-mediated organogenesis using a mechanism analogous to that used by NPH3/PHOT1 in phototropism. The findings put yuc, npy1, and known auxin mutants pin1, pid, and mp in a genetic framework for further understanding of the mechanisms governing auxin-regulated plant development. The findings also reveal a novel mechanism for AGC kinase-mediated signal transduction in plants. The primary aims of the proposed studies are (1) Analysis of the mechanisms of YUC genes in auxin biosynthesis and plant development; (2) Elucidation of the biochemical mechanisms of NPY1 in auxin-regulated organogenesis; (3) Determination of the unique and overlapping functions of the NPY1 family genes in auxin-regulated plant development; (4) Genetic dissection of the mechanisms by which auxin regulates plant development. The proposed experiments will provide significant new insight into the molecular mechanisms of auxin action in plant development, particularly in organogenesis. A clear understanding of the mechanisms by which auxin regulates complex developmental processes is of fundamental importance to plant biology and will have a significant agricultural impact. The proposed study will also extend our understanding of signaling mechanisms controlling complex developmental processes in other eukaryotes, particularly the mechanisms of AGC kinases, which have been implicated in diverse developmental programs in other organisms including humans. PUBLIC HEALTH RELEVANCE: The proposed research is aimed to elucidate the molecular mechanisms by which auxin controls the formation of plant organs. The proposed research will augment our understanding of complex signal transduction mechanisms governing organogenesis and other developmental processes in eukaryotes including humans.

描述（由申请人提供）：生长素是植物生长和发育的几乎各个方面的重要调节剂。该提案的总体目标是阐明生长素调节植物器官发生和其他发育过程的分子机制。在上一次资助期间，我们证明了丝兰 (YUC) 黄素单加氧酶在生长素生物合成和各种发育过程（包括胚胎发生、幼苗生长、维管图案形成和花发育）中发挥着重要作用。先前对生长素信号传导的遗传学研究集中于对外源生长素抗性突变体的分析。我们对生长素生物合成的理解使我们能够从完全不同的角度阐明植物发育中生长素作用的分子机制。我们从部分生长素缺陷的 yuc1 yuc4 双突变体的增强子遗传筛选中鉴定出 npy1（yuc 突变体中的裸针）。 npy1 yuc1 yuc4 三重突变体发育出针状花序，但未能形成任何花，这是由生长素途径缺陷引起的标志性表型。 NPY1 属于一个大家族，与非向光性下胚轴 3 (NPH3) 同源，后者是一种与 AGC 激酶 PHOT1 一起调节向光性的 BTB 蛋白。 NPY1 与 PID（PHOT1 同源物）一起使用类似于 NPH3/PHOT1 在向光性中使用的机制来调节生长素介导的器官发生。研究结果将 yuc、npy1 和已知的生长素突变体 pin1、pid 和 mp 置于遗传框架中，以进一步了解控制生长素调节植物发育的机制。研究结果还揭示了植物中 AGC 激酶介导的信号转导的新机制。本研究的主要目的是（1）分析YUC基因在生长素生物合成和植物发育中的作用机制； (2) 阐明NPY1在生长素调控器官发生中的生化机制； (3) 确定NPY1家族基因在生长素调控植物发育中的独特和重叠功能； (4)生长素调节植物发育机制的遗传解析。拟议的实验将为植物发育，特别是器官发生中生长素作用的分子机制提供重要的新见解。清楚地了解生长素调节复杂发育过程的机制对于植物生物学至关重要，并将产生重大的农业影响。拟议的研究还将扩展我们对控制其他真核生物复杂发育过程的信号机制的理解，特别是 AGC 激酶的机制，它与包括人类在内的其他生物体的多种发育程序有关。公共健康相关性：拟议的研究旨在阐明生长素控制植物器官形成的分子机制。拟议的研究将增强我们对控制包括人类在内的真核生物的器官发生和其他发育过程的复杂信号转导机制的理解。