Integration of Ethylene and Light in the Control of Phototaxis in Synechocystis sp. PCC 6803

乙烯和光在集胞藻趋光性控制中的整合。

• 批准号: 1254423
• 负责人: Brad Binder
• 金额: $ 30万
• 依托单位: University of Tennessee Knoxville
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1254423&HistoricalAwards=false
• 关键词: Integration; Ethylene; Light; Control; Phototaxis

A major challenge in biology is to understand how events at the biochemical level lead to changes at the organismal level. In cyanobacteria, light stimulates movement towards (positive phototaxis) and away from (negative phototaxis) light. This is an important survival mechanism in cyanobacteria. The cyanobacterium Synechocystis contains a protein (SynETR) that has characteristics of both photoreceptors (important for phototaxis) and ethylene receptors. In plants, ethylene receptors mediate many responses that impact plant survival, but it is unknown what these receptors do in cyanobacteria. Prior results have shown that ethylene regulates phototaxis in Synechocystis via the SynETR protein. However, no detectable biosynthesis of ethylene was found. It is known that sunlight can interact with dissolved organics to abiotically produce ethylene in the concentration range where physiological effects on phototaxis are seen. Thus, this project tests the hypothesis that Synechocystis uses ethylene as an external chemical cue to influence phototaxis behavior. The overall goal is to elucidate the mechanism by which ethylene affects SynETR function in Synechocystis to modulate phototaxis. A combination of biochemistry, chemistry, physiology, and molecular biology will be used to address this goal. This combination of approaches has yielded a great deal of information about the ethylene receptors in plants and provides a paradigm for determining the function of SynETR in Synechocystis. The multifaceted research will increase our understanding about links between ethylene binding events at the biochemical level with physiological changes that occur at the organismal level. This, in turn, will provide a broader understanding about how cyanobacteria respond to their environment and integrate environmental cues to modulate phototaxis.The research will enhance research and educational infrastructure by broadening opportunities for high school, undergraduate and graduate students to engage in research. Since cyanobacteria contribute significantly to atmospheric oxygen levels and fix a large portion of carbon in the atmosphere, it is important to understand the effects of ethylene on these organisms because levels of ethylene in the atmosphere continue to rise as an air pollutant from industrial activities. Additionally, a better understanding about ethylene and its impact on cyanobacteria will help us determine how to maximize their use for bioenergy needs.

生物学的一个主要挑战是了解生化水平的事件如何导致有机体水平的变化。在蓝细菌中，光刺激朝向（正趋光性）和远离（负趋光性）光的运动。这是蓝细菌的重要生存机制。蓝藻集胞藻含有一种蛋白质 (SynETR)，该蛋白质具有光感受器（对趋光性很重要）和乙烯受体的特征。在植物中，乙烯受体介导许多影响植物生存的反应，但尚不清楚这些受体在蓝细菌中的作用。先前的结果表明，乙烯通过 SynETR 蛋白调节集胞藻的趋光性。然而，没有发现可检测到的乙烯生物合成。众所周知，阳光可以与溶解的有机物相互作用，在对趋光性产生生理效应的浓度范围内非生物地产生乙烯。因此，该项目测试了集胞藻使用乙烯作为外部化学线索来影响趋光行为的假设。总体目标是阐明乙烯影响集胞藻中 SynETR 功能以调节趋光性的机制。将结合生物化学、化学、生理学和分子生物学来实现这一目标。这种方法的结合产生了大量有关植物乙烯受体的信息，并为确定集胞藻中 SynETR 的功能提供了范例。多方面的研究将增进我们对生化水平上的乙烯结合事件与生物体水平上发生的生理变化之间联系的理解。反过来，这将为蓝藻如何响应其环境并整合环境线索来调节趋光性提供更广泛的了解。该研究将通过扩大高中生、本科生和研究生参与研究的机会来加强研究和教育基础设施。由于蓝藻对大气中的氧气水平有显着贡献，并固定了大气中的大部分碳，因此了解乙烯对这些生物体的影响非常重要，因为作为工业活动的空气污染物，大气中的乙烯水平持续上升。此外，更好地了解乙烯及其对蓝藻的影响将有助于我们确定如何最大限度地利用它们来满足生物能源需求。