NASA/NSF Collaborative Research: Evaluating Phytohormone Signal Transduction Using Xenopus oocytes

拟议研究的长期目标是确定参与植物对环境刺激反应的信号转导成分。利用非洲爪蟾卵母细胞/mRNA注射系统，将重点研究高等植物对低非冷冻温度和脱水环境刺激的信号转导反应。这两种刺激对植物的共同作用是调节内源脱落酸（ABA）水平，并不是所有的低温反应都依赖于ABA。ABA的作用方式尚未得到确切证实。关于ABA受体的实际位置，以及信号转导所必需的第二信使（如果有的话），问题仍然存在。拟议的研究将首先集中在ABA上，因为文献中有证据表明ABA刺激钙的释放。本实验室的初步数据表明，ABA可能与质膜受体相互作用，导致细胞内钙的增加。本研究的具体目的是：1)表征烟草mRNA注射后卵母细胞对ABA和几种ABA类似物的反应。2)如果Ca被动员，定位其来源，试图确定ABA及其受体的功能方式。如果Ca没有被动员，确定ABA正在利用的备选第二信使系统。3)利用爪蟾卵母细胞系统分离ABA受体cDNA克隆并进行鉴定。了解ABA和受体如何相互作用将有助于理解植物对低温和脱水刺激的共同反应。建议的研究将涉及电生理学、分子生物学、生物化学和细胞生物学等领域。这项研究的综合性质将使研究有可能在适当的合作研究实验室进行，并将被证明是培养博士后助理和研究生的有益和令人兴奋的环境。* * *

9416035 Sutton The long-term objective of the proposed research is to identify signal transduction components involved in plant response to environmental stimuli. Using the Xenopus oocyte/mRNA injection system, research proposed will focus on signal transduction in response to the environmental stimuli of low non-freezing temperature and dehydration in higher plants. A common effect of these two stimuli on plants is to modulate endogenous abscisic acid (ABA) levels, not all responses to low temperature are ABA dependent. The mode of action of ABA has not been conclusively demonstrated. Questions remain regarding actual location of ABA receptors, and second messengers, if any, that are necessary for signal transduction. Research proposed will initially focus on ABA, since there is evidence in the literature of ABA stimulating Ca release. Preliminary data from this lab suggests that ABA may interact with plasma membrane receptors and cause an increase in intracellular Ca. Specific aims of this proposal are: 1) To characterize the responses, to ABA and several ABA analogues, from oocytes injected with tobacco mRNA. 2) If Ca is mobilized, to localize its source in an attempt to determine the manner in which ABA and its receptors are functioning. If Ca is not mobilized, to determine the alternative second messenger system being utilized by ABA. 3) To utilize the Xenopus oocyte system to isolate and characterize ABA receptors cDNA clones. Knowing how ABA and receptor(s) interact will help in understanding plant responses common to the stimuli of low temperature and dehydration. Research proposed will involve the areas of electrophysiology, molecular biology, biochemistry and cell biology. The integrative nature of this research will make it possible for research to be performed at appropriate collaborative research laboratories and will prove to be a rewarding and exciting environment for training of postdoctoral associates and graduate students. ** *