Discovery of a Novel Signal that Enhances Germination and Seedling Growth

发现促进发芽和幼苗生长的新信号

• 批准号: 1557962
• 负责人: David Nelson
• 金额: $ 55万
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-03-15 至 2017-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1557962&HistoricalAwards=false
• 关键词: Discovery; Novel; Signal; Enhances; Germination

Plant hormones control how and when plants grow, and how plants react to their environment. Manipulating plant hormones with chemical and genetic tools has been instrumental in the green revolution; a deeper understanding of how hormones control plant growth will likely fuel future advances in agriculture. In this project, biological sensors will be developed to detect a recently recognized plant hormone called strigolactone, and an unknown molecule in plants (KL) that controls seed germination, seedling growth, and leaf shape. The biological sensors will be used in this project to purify KL, which may be a novel hormone, and to identify genes that produce it. Discovery of KL may lead to the development of new agrichemicals or genetic modifications that promote uniform seed germination and seedling vigor, thus increasing crop yields. Strigolactone sensors will be useful tools for plant breeders to more easily develop crops with altered strigolactone levels, which can in turn influence the fertilizer requirements of crops and their susceptibility to weeds. Undergraduate students and a postdoctoral researcher will be trained in research skills and scientific communication, leading to enhancement of the scientific workforce. Research discoveries will be communicated to the public through journal publications, press releases, news articles, and local speaking opportunities.Karrikins are compounds found in smoke that promote seed germination after fire and enhance seedling vigor. The karrikin signaling pathway is highly similar to the strigolactone signaling pathway, suggesting common ancestry. A receptor that is necessary for karrikin responses, KARRIKIN INSENSITIVE 2 (KAI2), has been identified, but karrikins are unlikely to be its native ligand. The aims of this project are to (1) develop sensitive and specific biological assays to detect the unknown KAI2 ligand (KL) and strigolactones, (2) identify genes involved in KL biosynthesis, and (3) highly purify KL from plant extracts as a steppingstone toward its identification. Biological sensors for karrikins/KL and strigolactones based on transcriptional or proteolytic responses will be engineered. These bioassays will be used in genetic screens to identify KL-deficient mutants. Finally, bioassay-guided fractionation will be used to isolate KL in small molecule extracts from plants. The discovery of KL and KL biosynthesis genes will catalyze a new field of research in plant biology that impacts the understanding of seed dormancy, seedling photomorphogenesis, and leaf development. It will also provide insights into the ancestral function of the KAI2 signaling mechanism in basal land plants, which later duplicated and evolved to mediate growth control by strigolactones.

植物激素控制植物的生长方式和何时生长，以及植物如何对环境反应。用化学和遗传工具操纵植物激素在绿色革命中发挥了作用。对激素控制植物的增长的更深入了解可能会推动未来的农业进步。在该项目中，将开发生物传感器，以检测一种新近识别的植物激素，称为Strigolactone，以及控制种子发芽，幼苗生长和叶状形状的植物中未知分子（KL）。该项目将使用该生物传感器净化KL，这可能是一种新型的激素，并鉴定产生它的基因。 KL的发现可能会导致新的农业化学物质或遗传修饰的发展，从而促进均匀的种子发芽和幼苗活力，从而增加作物产量。斯特龙酮传感器将是植物育种者更容易开发带有斯特龙酮水平改变的农作物的有用工具，这反过来又会影响农作物的肥料需求及其对杂草的易感性。本科生和博士后研究人员将接受研究技能和科学交流的培训，从而增强科学劳动力。研究发现将通过期刊出版物，新闻稿，新闻文章和当地演讲机会传达给公众。卡里金斯是在烟雾中发现的化合物，可以在火灾后促进种子发芽并增强幼苗的活力。 Karrikin信号通路与Strigolactone信号通路高度相似，这表明是共同的血统。已经确定了Karrikin Nomentiments 2（Kai2）所必需的一种受体，但Karrikins不太可能是其本地配体。该项目的目的是（1）开发敏感和特定的生物学测定，以检测未知的KAI2配体（KL）和strigolactones，（2）识别涉及KL生物合成的基因，（3）（3）高度纯化的KL植物提取物作为垫脚石的植物提取物的识别。基于转录或蛋白水解反应的Karrikins/KL和Strigolactones的生物传感器将进行设计。这些生物测定将用于遗传筛选中，以鉴定KL缺陷型突变体。最后，生物测定引导的分级将用于分离植物中的小分子提取物中的KL。 KL和KL生物合成基因的发现将催化植物生物学研究的新领域，从而影响对种子休眠，幼苗光塑料发生和叶片发育的理解。它还将提供有关基底陆地植物中KAI2信号传导机制的祖先功能的见解，后来复制并进化为介导strigolactones的生长控制。