The Role of Leucine Aminopeptidase in Plant Defense

亮氨酸氨肽酶在植物防御中的作用

• 批准号: 9318260
• 负责人: Linda Walling
• 金额: $ 44万
• 依托单位: University of California-Riverside
• 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: 1994-04-01 至 2000-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9318260&HistoricalAwards=false
• 关键词: Role; Leucine; Aminopeptidase; Plant; Defense

9318260 Walling Aminopeptidases are exopeptidases that hydrolyze the N-terminal amino acid from peptides and proteins. In animals, aminopeptidases have an important role in nutrition and modulation of the activities of gut and brain peptide hormones by converting them to active or inactive forms. In addition, these exopeptidases may have a role in modulating half-lives of proteins in vivo. Surprisingly; little is known about aminopeptidase activity during plant development. Although aminopeptidases are known to be induced after germination and during senescence, the expression of these genes during the plant life cycle or in response to biotic or abiotic stress has not been characterized. Dr. Walling has isolated and characterized a leucine aminopeptidase (lap) cDNA clone from Lycopersicon exculentum (tomato). Leucine aminopeptidase mRNAs are induced to high levels after mechanical injury, insect feeding, and Pseudomonas syringae pv. tomato infection. LAP proteins and activity are also induced after wounding. Two wound-induced lap genes are present in the tomato. The proposed research is a multi-faceted approach to understanding the expression, localization, and function of LAPs during the plant-defense response. Furthermore, these studies will be exteded to gain a comprehensive understanding of lap gene expression throughout plant development and in response to abiotic stress. Only recently, have plant leucine aminopeptidase genes been isolated, and few directed efforts have been made to understand their expression and impact on the plant responses to the environment and to developmental cues. Elucidation of the role of LAPs during the plant defense reaction and during development will enhance our understanding of the mechanisms that favor optimal growth and development. These factors will directly impact on optimal crop productivity and potentially yield insights for strategies to enhance a plant's endogenous protection mechanisms. ***

9318260 Walling Aminopeptidases是从肽和蛋白质水解N-末端氨基酸的外肽酶。 在动物中，氨肽酶通过将肠和脑肽激素转化为活性或非活性形式，在营养和调节肠和脑肽激素的活性方面具有重要作用。 此外，这些外肽酶可能在体内调节蛋白质的半衰期中起作用。 令人惊讶的是，对植物发育过程中的氨肽酶活性知之甚少。 虽然已知氨肽酶在发芽后和衰老期间被诱导，但这些基因在植物生命周期期间或响应于生物或非生物胁迫的表达尚未被表征。 Walling博士从番茄中分离出一个亮氨酸氨肽酶（lap）cDNA克隆，并对其进行了鉴定。 亮氨酸氨肽酶mRNA在机械损伤、昆虫取食和假单胞菌pv.番茄感染 创伤后也可诱导表达β-淀粉样蛋白和活性。 两个伤口诱导的lap基因存在于番茄中。 这项研究是一个多方面的方法来了解LAPs在植物防御反应中的表达，定位和功能。 此外，这些研究将扩展到获得一个全面的了解lap基因的表达在整个植物发育和响应非生物胁迫。 直到最近，植物亮氨酸氨肽酶基因被分离出来，很少有针对性的努力已经了解他们的表达和影响植物对环境和发育线索的反应。 阐明LAPs在植物防御反应和发育过程中的作用将增强我们对有利于最佳生长和发育的机制的理解。 这些因素将直接影响作物的最佳生产力，并可能为增强植物内源保护机制的策略提供见解。 ***