The ACC Synthase Genes and Polypeptides

ACC合酶基因和多肽

• 批准号: 9316475
• 负责人: Athanasios Theologis
• 金额: $ 50万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-01-15 至 1999-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9316475&HistoricalAwards=false
• 关键词: ACC; Synthase; Genes; Polypeptides

9316475 Theologis The specific aims of the proposal are : 1) To isolate and structurally characterize the rest of the tomato ACC synthase genes. To characterize the expression characteristics of each tomato gene during growth and development and to define the type of inducer(s) responsible for their induction. To characterize the expression characteristics of the Arabidopsis ACS4 and ACS5 genes in the presence of indoleacetic acid (IAA) and Li+, respectively. To define the cisacting elements for IAA inducibility of the Arabidopsis ACS4 and Li+ responsive elements of the ACS5 gene. The elements will be defined by ExoIII deletion analysis of the promoter regions. Promoter constructs with the CAT reporter gene will be transiently assayed in Arabidopsis protoplasts. The functionally of the elements will be verified by stable transformation experiments. To inhibit growth of rice under hypoxia using antisense OS-ACs1 RNA and to define the cell types that express two rice genes OS-ACS1 and 3 under low O2 tension. To define the critical residues required for enzymatic activity of ACC synthase by in vitro mutagenesis and expression experiments in E. coli. To perform intermolecular complementation experiments in E. coli for determining whether ACC synthase is a dimer with two active sites. To inhibit ethylene dependent developmental processes by overexpression of dominant negative mutations of specific isoenzymes. To biochemically characterize the Arabidopsis ACC synthase isoenzymesfor defining their biochemical diversity. %%% Ethylene is an unique plant signaling molecule. The hydrocarbon gas, known as the fruit ripening hormone, controls many aspects of plant growth and development, and its synthesis is highly regulated. Recent experimental evidence indicates that the key enzyme in the ethylene biosynthetic pathway, 1-aminocyclopropane-1- carboxylic acid (ACC) synthase is encoded by a highly divergent multigene family in various mono-and dicotyledonous plant s. The members of each family are differentially regulated by various inducers and developmental stages. Studies on the structure and regulation of the ACC synthase genes in tomato (Lycopersicon esculentum), rice (Oryza sativa) and Arabidopsis thaliana are proposed here to gain insight into the details of the biochemical mechanisms that regulate their expression by various hormones and stress conditions as well as their role in regulating plant growth. Furthermore, in vitro mutagenesis studies are proposed to obtain fundamental knowledge about the structure and function of the ACC synthase protein. ***

9316475理论：该提案的具体目的是：1)分离和鉴定番茄ACC合成酶基因的其余部分。研究番茄各基因在生长发育过程中的表达特点，并确定负责诱导的诱导剂(S)的类型。研究吲哚乙酸(IAA)和Li+对拟南芥ACS4和ACS5基因表达的影响。确定拟南芥ACS4基因IAA诱导的顺式作用元件和ACS5基因的Li+反应元件。这些元件将通过ExoIII启动子区域的缺失分析来确定。带有CAT报告基因的启动子构建将在拟南芥原生质体中进行瞬时检测。这些元素的功能将通过稳定相变实验来验证。利用反义OS-ACs1 RNA抑制水稻在低氧条件下的生长，并确定在低氧胁迫下表达两个水稻基因OS-ACS1和3的细胞类型。通过体外诱变和在大肠杆菌中的表达实验，确定ACC合成酶活性所需的关键残基。在大肠杆菌中进行分子间互补实验，以确定ACC合成酶是否是具有两个活性位点的二聚体。通过过度表达特定同工酶的显性负突变来抑制乙烯依赖的发育过程。对拟南芥ACC合成酶同工酶进行生化特征分析，以确定其生化多样性。乙烯是一种独特的植物信号分子。碳氢化合物气体被称为水果成熟激素，控制着植物生长和发育的许多方面，其合成受到高度调控。最近的实验证据表明，乙烯生物合成途径中的关键酶1-氨基环丙烷-1-羧酸合成酶是由不同单双子叶植物S中高度分化的多基因家族编码的，每个家族的成员受到不同诱导物和发育阶段的不同调控。本文对番茄、水稻和拟南芥ACC合成酶基因的结构和调控进行了研究，以期深入了解不同激素和胁迫条件调节ACC合成酶基因表达的生化机制以及它们在植物生长调控中的作用。此外，建议进行体外诱变研究，以获得关于ACC合成酶蛋白的结构和功能的基础知识。***