Effects of Developmental Changes on the Physiological Processes that Regulate Photosynthetic Responses to Climate Change

发育变化对调节光合作用对气候变化反应的生理过程的影响

• 批准号: 0130885
• 负责人: James Lewis
• 金额: $ 22.5万
• 依托单位: Fordham University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0130885&HistoricalAwards=false
• 关键词: Effects; Developmental; Changes; Physiological; Processes

Increasing atmospheric carbon dioxide concentrations and other atmospheric and climate changes may substantially alter plant growth. Differences in growth responses within and between plant species may have substantial impacts on biodiversity, carbon sequestration and other ecosystem functions by altering community composition and changing the movement of carbon, nutrients and water through ecosystems. However, despite extensive research over the last several decades, fundamental problems remain with predicting effects of climate change on plants. For example, carbon dioxide uptake by plants, a standard measure of climate change effects on carbon sequestration potential, has been found to vary substantially from carbon accumulation in plants. To account for this variability, a source-sink feedback mechanism is frequently invoked that links changes in carbon uptake (photosynthesis) with developmental changes that affect carbon accumulation. This mechanism is driven by changes in the balance between source activity (carbon uptake) and sink capacity (carbon accumulation). However, few studies have actually manipulated plant development to analyze the effects of normal developmental changes on physiological processes that regulate photosynthetic responses to climate change. As a result, the role of plant development in regulating photosynthetic responses to climate change is poorly understood. The overall goal of the proposed research is to develop a mechanistic understanding of the effects of developmental changes as plants age on the physiological processes that regulate photosynthetic responses to climate change. To identify key developmental and physiological processes that regulate photosynthesis, two key developmental processes, plant ontogeny (the timing and duration of developmental events) and morphological changes as plants age, will be independently manipulated. Planting cohorts of plants on different dates and inducing all cohorts to flower simultaneously will independently manipulate ontogeny and plant size. To avoid the confounding effect of accelerated ontogeny induced by growth in elevated carbon dioxide concentrations, a developmentally determinate, short-day species (Xanthium strumarium L.) will be used. In addition, because temperature is a key component of climate change and nitrogen supply is a critical factor regulating interactions between developmental and physiological processes, these factors will be manipulated to examine how they mediate the effects of developmental changes on photosynthesis. The results of this study will increase our understanding of the effects of changes in plant ontogeny and morphology on photosynthetic responses to climate change. More broadly, this study will increase our understanding of the links between carbon uptake and growth responses of plants to environmental change.

增加大气二氧化碳浓度以及其他大气和气候变化可能会大大改变植物的生长。 通过改变社区组成并改变碳，养分和水的运动，植物物种内部和植物之间生长反应的差异可能会对生物多样性，碳隔离和其他生态系统功能产生重大影响。 但是，尽管在过去几十年中进行了广泛的研究，但预测气候变化对植物的影响仍然存在基本问题。 例如，已经发现，植物二氧化碳吸收二氧化碳的摄取，这是气候变化对碳封存潜力的影响的标准量度，与植物中的碳积累有很大差异。 为了解决这种可变性，经常调用源链接反馈机制，该机制将碳吸收（光合作用）的变化与影响碳积累的发育变化联系起来。 这种机制是由源活动（碳吸收）和水槽容量（碳积累）之间平衡的变化驱动的。 然而，实际上很少有研究操纵植物的发展，以分析正常发育变化对调节气体对气候变化的光合反应的生理过程的影响。 结果，植物发育在调节对气候变化的光合作用反应中的作用知之甚少。 拟议的研究的总体目标是，随着植物的年龄对调节气候变化的光合反应的生理过程，随着植物的年龄对发育变化的影响的机械理解。 为了确定调节光合作用的关键发育和生理过程，将独立操纵​​光合作用的两个关键发育过程，植物本体的发育（发育事件的时机和持续时间）和形态变化，随着植物的年龄，将被独立操纵。 在不同的日期种植植物的同类人群，并同时诱使所有同时花的花朵会独立操纵本体发育和植物大小。 为了避免二氧化碳浓度升高引起的加速个体发育的混杂作用，将使用发育确定的短期物种（xanthium strumarium L.）。 此外，由于温度是气候变化和氮供应的关键组成部分，是调节发育和生理过程之间相互作用的关键因素，因此将操纵这些因素以检查它们如何介导发育变化对光合作用的影响。这项研究的结果将提高我们对植物本体的变化和形态变化对气候变化的光合反应的影响。 更广泛地说，这项研究将增加我们对碳吸收与植物与环境变化的增长反应之间联系的理解。