Auxin Biosynthesis and Signaling Mechanisms

生长素生物合成和信号传导机制

• 批准号: 7652823
• 负责人: YUNDE ZHAO
• 金额: $ 32.2万
• 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/7652823
• 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; 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; Yucca; base; indoleacetic acid; insight; mutant; novel; plant growth/development; programs; public health relevance; 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）：生长素几乎是植物生长和开发几乎每个方面的重要调节剂。该提案的一般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。在最后一个赠款期间，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中起着至关重要的作用，包括胚胎生成，幼苗生长，血管图案和花卉发育。先前对生长素信号传导的遗传研究集中于对外源生长素抗性的突变体分析。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生长素作用在植物发育中的分子机制。我们从遗传筛选中鉴定了NPY1（YUC突变体中的裸销），用于增强YUC1 YUC4双突变体的增强子，这些突变体部分副感症状不足。 NPY1 YUC1 YUC4三重突变体形成了销子状的花序，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，与非光质下胃基3（NPH3）是同源的，这是一种BTB蛋白，调节光促性型以及AGC激酶Phot1。 NPY1与PHOT1同源物PID一起使用，使用与NPH3/Phot1在光质中使用的机制相似的机制来调节生长素介导的器官。这些发现将YUC，NPY1和已知的生长素突变体PIN1，PID和MP置于遗传框架中，以进一步了解有关生长素调节植物发育的机制。这些发现还揭示了植物中AGC激酶介导的信号转导的新型机制。拟议研究的主要目的是（1）分析YUC基因在生长素生物合成和植物发育中的机制； （2）在生长素调节的器官发生中NPY1的生化机理阐明； （3）确定在生长素调节的植物发育中NPY1家族基因的独特和重叠功能； （4）生长素调节植物发育的机制的遗传解剖。提出的实验将为生长素作用在植物发育中，特别是在器官发生中的分子机制提供重大的新见解。对生长素调节复杂发育过程的机制的清晰理解对于植物生物学至关重要，并且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中复杂发育过程的信号传导机制的理解，尤其是AGC激酶的机制，AGC激酶的机制与其他生物体的各种发育计划有关。公共卫生相关性：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包括人类在内的真核生物中机器发生和其他发育过程的复杂信号转导机制的理解。