Integration of plant responses to multiple stressors over time: interactions between winter and summer

随着时间的推移植物对多种应激源的反应的整合：冬季和夏季之间的相互作用

• 批准号: RGPIN-2015-06178
• 负责人: Henry, Hugh
• 金额: $ 3.57万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=613989
• 关键词: Integration; plant; responses; multiple; stressors

Response to multiple stresses has been a key topic in plant research, particularly in the context of global environmental change. While there has been a focus on plant responses to stresses that occur simultaneously, such as drought and heat stress, interactions between stresses also can occur sequentially in time. In some cases changes in the physiology of a plant in response to an initial stress can decrease vulnerability to future stress. However, in contrast to the potential benefits of this 'stress memory,' declines in plant condition in response to the initial stress can decrease the ability to tolerate future stress. Such interactions between multiple stresses have been studied extensively in the context of the growing season. In contrast, studies of carryover effects of winter stress on summer stress responses are lacking, despite the potential for variability in winter conditions to influence plant growing season performance substantially. Synergies between plant responses to variability in winter conditions and stress tolerance over summer are further complicated when examined in an ecosystem context. For example, frost not only has the potential to damage overwintering plants, but it also can affect soil microorganisms, nutrient availability, soil physical properties and moisture, and the interactions of these factors need to be accounted for when examining overall plant responses. The overarching question I will address with my research program is how variability in winter conditions alters the subsequent responses of herbaceous plants to stress over summer. I hypothesize that while frost damage over winter can reduce the performance of plants over summer, exposure to stress over winter nevertheless has the potential to reduce the vulnerability of plants to summer stresses. I will test this hypothesis and explore how soil processes can contribute to interactions between winter conditions and summer stress using a combination of controlled environment and field experiments. My short term objective is to examine how the timing and severity of frost exposure affect summer drought tolerance, the importance of direct effects versus the indirect effects in explaining interactions between frost and drought, and the performance tradeoffs that limit the abilities of plants with high stress memory to capitalize on extended growing season length. My long term objective is to examine the broader significance of plant winter/summer stress interactions in influencing plant community and ecosystem level processes, including plant species composition, soil nitrogen availability and retention, and plant litter decomposition. In terms of impact, my research will provide crucial information for predicting changes in species distributions and ecosystem function in response to extreme climate events, and transform how winter processes are integrated into plant and ecosystem ecology.

植物对多重胁迫的响应一直是植物研究的一个重要课题，特别是在全球环境变化的背景下。虽然人们一直关注植物对同时发生的胁迫（如干旱和热胁迫）的反应，但胁迫之间的相互作用也可以在时间上顺序发生。在某些情况下，植物对初始胁迫的生理变化可以降低对未来胁迫的脆弱性。然而，与这种“压力记忆”的潜在好处相反，植物对初始压力的反应会降低耐受未来压力的能力。在生长季节的背景下，已经广泛研究了多种压力之间的这种相互作用。与此相反，冬季应力对夏季应力反应的结转影响的研究是缺乏的，尽管在冬季条件的变化，影响植物生长季节的表现显着的潜力。植物对冬季条件变化的反应与夏季的胁迫耐受性之间的协同作用在生态系统背景下进一步复杂化。例如，霜冻不仅有可能损害越冬植物，而且还可能影响土壤微生物、养分供应、土壤物理性质和水分，在检查整体植物反应时，需要考虑这些因素的相互作用。 我将在我的研究计划中解决的首要问题是，冬季条件的变化如何改变草本植物在夏季对压力的后续反应。我假设，虽然霜冻损害在冬季可以降低植物的性能在夏季，暴露于压力在冬季仍然有可能减少植物对夏季压力的脆弱性。我将测试这一假设，并探讨土壤过程如何有助于冬季条件和夏季压力之间的相互作用，使用受控环境和田间实验相结合。我的短期目标是研究霜冻暴露的时间和严重程度如何影响夏季干旱耐受性，直接效应与间接效应在解释霜冻和干旱之间的相互作用中的重要性，以及限制具有高应力记忆的植物利用延长的生长季节长度的能力的性能权衡。我的长期目标是研究植物冬/夏胁迫相互作用在影响植物群落和生态系统水平过程中的更广泛意义，包括植物物种组成，土壤氮的有效性和保留，以及植物凋落物分解。在影响方面，我的研究将为预测物种分布和生态系统功能的变化提供关键信息，以应对极端气候事件，并改变冬季过程如何融入植物和生态系统生态学。