Polypeptide Signaling in Plants

因此，研究多肽信号在植物中的作用和程度是十分必要的。 动物和酵母利用多肽信号来调节许多生理过程，包括应激、繁殖、发育和防御以及许多其他过程。直到1991年，当这个实验室在植物中发现第一个多肽信号时，公认的教条是植物不利用多肽信号，而是利用生长素、细胞分裂素、赤霉素、乙烯和脱落酸等小的化学激素作为生理过程的调节剂。 自1991年首次分离多肽信号以来，其他实验室已鉴定出四种新的多肽信号，我们实验室又鉴定并纯化了五种。 迄今为止报道的植物中的信号多肽参与防御、发育和繁殖。 因此，我们预计在不久的将来将查明更多的情况。 我们已经开发了一种新的，快速的测定，以确定在植物中的多肽信号，悬浮培养的细胞，响应受体介导的多肽信号引起的细胞培养基的pH值增加。使用该测定来监测纯化过程中的信号多肽，我们已经确定了五个受体介导的多肽信号从烟草，番茄和苜蓿，并利用该测定来调查整个植物界的多肽的存在。我们已经广泛地研究了第一个发现的多肽防御信号，在草食动物和病原体攻击时释放。 它是从番茄中分离的18个氨基酸的多肽，其衍生自200个氨基酸的前体。 我们已经发表了大量关于其在植物中的信号通路，并已确定和分离其受体在番茄细胞膜上。 我们目前正在分离受体基因，用于研究番茄细胞中受体的结构和功能。 我们也在寻找我们分离的新多肽的基因，以确定它们的前体，释放和作用的模式，以及它们在植物中的定位。 我们将继续鉴定和分离这些多肽的受体，并开始学习植物中多肽信号传导的基本原理。 我们对植物中信号多肽及其受体的研究将为植物防御和发育信号提供全新的理解，与生态学和农业具有重要的相关性。

Research is proposed to investigate the extent and roles of polypeptide signaling in plants. Animals and yeast utilize polypeptide signals for regulating a host of physiological processes, including stress, reproduction, development and defense, and many others. Until 1991, when this laboratory discovered the first polypeptide signal in plants, the accepted dogma was that plants did not utilize polypeptide signals, but used small chemical hormones such as auxin, cytokinins, gibberillins, ethylene and abscisic acid as regulators of physiological processes. Since the first isolation of a polypeptide signal in 1991, four new polypeptide signals have been identified in other laboratories, and five more have been identified and purified in our laboratory. The signaling polypeptides in plants reported to date are involved in defense, development, and reproduction. Thus, we expect many more to be identified in the near future. We have developed a novel, rapid assay to identify polypeptide signals in plants using suspension-cultured cells, which respond to receptor-mediated polypeptide signals by causing the pH of the cell culture medium to increase. Using the assay to monitor the signaling polypeptides during purification, we have identified five receptor-mediated polypeptide signals from tobacco, tomato and alfalfa and are utilizing the assay to investigate the presence of polypeptides throughout the plant kingdom. We have extensively studied the first discovered polypeptide defense signal that is released upon herbivore and pathogen attacks. It is an 18 amino acid polypeptide isolated from tomato, that is derived from a 200 amino acid precursor. We have published extensively on its signaling pathway in plants and have identified and isolated its receptor on tomato cell membranes. We are currently isolating the receptor gene for studies of the structure and function of the receptor in tomato cells. We are also seeking the genes for the new polypeptides we have isolated to determine their precursors, the mode of release and action, and their localization in plants. We will continue to identify and isolate the receptors of these polypeptides and begin to learn the broad fundamental principles that underlie polypeptide signaling in plants. Our studies of signaling polypeptides and their receptors in plants will provide an entirely new understanding of plant signaling for defense and development, with important relevance to ecology and agriculture.