Delineating the Roles of Rising CO2 and Temperature on Flowering Time across Pre-industrial through Future Conditions

描述从工业化前到未来条件下二氧化碳和温度上升对开花时间的作用

• 批准号: 1457236
• 负责人: Lena Hileman
• 金额: $ 68.12万
• 依托单位: University of Kansas Center for Research Inc
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2022-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1457236&HistoricalAwards=false
• 关键词: Delineating; Roles; Rising; CO2; Temperature

Flowering time has a large influence on ecological and evolutionary processes of plants. If flowering time is delayed, reproduction may be insufficient or may fail if seed set is not achieved by the end of the growing season. In contrast, if the transition to flowering is too rapid, the full length of the growing season may not be utilized for optimizing reproduction. As a result, shifts in flowering time can alter plant productivity, disrupt plant-pollinator interactions, and affect food production in crops. Climate change is expected to have major impacts on the flowering times of plants. While some species are known to have flowered earlier over the last century in response to warming, others may be more influenced by rising atmospheric carbon dioxide, or both factors combined. Little is known about the mechanisms that drive elevated carbon dioxide effects on flowering time. This may prove problematic, since over half of plant species are known to exhibit major alterations in flowering time when grown at elevated carbon dioxide levels predicted for 50 years into the future. Such responses will have global implications since carbon dioxide is rising across the planet. The overall goal of this research is to better understand the linkages between growth, physiological, and molecular mechanisms that control flowering time in response to both rising carbon dioxide and temperature across contemporary through future time scales. The Principal Investigator will help develop the new "Flower and Food Garden of Southwest Middle School" in Lawrence, KS, which will be an educational garden where students will apply current adaptation strategies in planting times under climate change scenarios and will measure food production. This will enable students to conduct hands-on research, analyze their own data, and report their findings to the community. Moreover, these outreach efforts will help to develop a more informed society on the effects of climate change on plants. These efforts will also promote a stronger workforce that will enable strategies to overcome the negative effects of climate change on food production through increased understanding of plant mechanistic responses to the environment.The goal of this research is to better understand the linkages between growth, physiological, and molecular mechanisms that control flowering time (FLT) in response to both rising [CO2] and temperature across pre-industrial through future conditions. In preliminary studies with field-collected genotypes of Arabidopsis thaliana, it was determined that rising [CO2] was the main driver of accelerated FLTs between preindustrial and modern conditions, while surprisingly, the addition of higher temperature reduced or eliminated this response. These are among the first results to delineate the effects of rising [CO2] and temperature that occurred over the last century on FLT. Furthermore, between modern and future conditions, high levels of variation were observed among genotypes for FLT responses, which would have major ecological and evolutionary implications if represented in other species. It is becoming increasingly clear that the influence of increasing [CO2] and temperature on FLT is not simply due to effects on growth rate. Rather, physiological responses and metabolite production can affect signaling mechanisms that influence flowering gene expression and alter the timing and size at which plants flower in response to climate change factors. Therefore, the proposed research takes an integrative approach to determine how the upstream effects of whole-plant growth, leaf-level physiology, and metabolite production interact to influence downstream effects on flowering gene expression and ultimately FLT in model plants and crops. Path analysis is used to determine the causal pathways that are most likely influencing FLT in response to [CO2] and temperature. Ultimately, the physiological, developmental, and molecular understanding developed in this research will increase the ability to predict FLT responses to contemporary and future changes in climate. The PI has a strong track-record of mentoring undergraduate students, including those from underrepresented populations, and this will continue throughout this research.

开花时间对植物的生态和进化过程有很大的影响。如果开花时间延迟，如果在生长季节结束时未达到种子，则可能不足或可能失败。相比之下，如果向开花的过渡太快，则可能不利用生长季节的全长来优化繁殖。结果，开花时间的转移会改变植物生产力，破坏植物 - 授粉的相互作用，并影响农作物的粮食生产。预计气候变化会对植物的开花时间产生重大影响。虽然已知某些物种在上个世纪早些时候开花是为了响应变暖，但其他物种可能会受到大气中二氧化碳的上升或两个因素的总和的影响。关于驱动二氧化碳对开花时间的影响的机制知之甚少。这可能是有问题的，因为已知超过一半的植物物种会在开花时表现出重大变化，而在未来预测的二氧化碳水平升高的时间为50年。由于二氧化碳在整个地球上正在上升，因此这种反应将具有全球影响。这项研究的总体目的是更好地了解生长，生理和分子机制之间的联系，这些结合响应于通过未来的时间尺度来控制二氧化碳和温度的响应。首席调查员将帮助开发堪萨斯州劳伦斯市的新的“西南中学的花朵和食品花园”，这将是一个教育花园，学生将在气候变化情景下在种植时间中采用当前的适应策略，并将衡量粮食生产。这将使学生能够进行动手研究，分析自己的数据并向社区报告他们的发现。此外，这些宣传工作将有助于发展一个更加知名的社会对气候变化对植物的影响。这些努力还将促进更强大的劳动力，这将通过增加对植物机械的反应来克服气候变化对粮食生产的负面影响。这项研究的目的是更好地理解对响应增长的生长，生理和分子机制控制开花时间（FLT）之间的联系[CO2]和跨越未来的情况。在对拟南芥的现场收集基因型的初步研究中，确定[CO2]上升是工业前和现代条件之间加速FLT的主要驱动力，而令人惊讶的是，较高的温度降低或消除了这种反应。这些是描述上个世纪在FLT上发生的[CO2]和温度上升的影响的最初结果之一。此外，在现代条件和未来条件之间，在基因型中观察到高水平的FLT反应，如果在其他物种中表示，这将具有重大的生态和进化意义。越来越清楚的是，升高[CO2]和温度对FLT的影响不仅是由于对生长速率的影响。相反，生理反应和代谢产物的产生会影响影响开花基因表达的信号机制，并改变植物对气候变化因子的开花的时机和大小。因此，拟议的研究采用了一种综合方法来确定全植物生长，叶片水平生理学和代谢产物的上游效应如何相互作用，以影响下游对开花基因表达的影响，最终在模型植物和农作物中最终产生FLT。路径分析用于确定最有可能影响[CO2]和温度的FLT的因果途径。最终，这项研究中发展的生理，发育和分子理解将提高预测气候中对当代和未来变化的FLT反应的能力。 PI拥有强大的指导本科生的赛道，包括来自代表性不足的人群，这将在整个研究中持续下去。