The unexplored direct response of leaf stomata to temperature (DRST): patterns, mechanisms and impacts

未探索的叶片气孔对温度的直接响应（DRST）：模式、机制和影响

• 批准号: 2307341
• 负责人: Thomas Buckley
• 金额: $ 69.39万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2307341&HistoricalAwards=false
• 关键词: unexplored; direct; response; leaf; stomata

Plants provide all the energy used by life on land, by taking CO2 from the air and using energy from the sun to turn it into sugar. During this process, water evaporates from leaves. In fact, most of the water that falls as rain returns to the atmosphere after evaporating from leaves. It is essential to understand how plants regulate water loss, both to identify which genes control that regulation, so that breeders can improve crop water use efficiency, and also to enable accurate predictions of how fluctuating weather and climate will affect water loss from crops, rangelands, and forests. Plants regulate water loss by opening and closing pores on the surfaces of leaves – for example, they open in sunlight, and close when soil is dry. However, little is known about how changes in temperature affect these pores. This study will determine those effects for 60 species, selected to represent most major habitats on Earth; test hypotheses for the biological causes of any temperature responses that are discovered; and incorporate these discoveries in a computer model to predict how temperature responses affect plant growth and water loss. In addition to training of undergraduate and graduate students in modern experimental plant biology, an experiential project will be developed in which students from a nearby high school with a large population of underprivileged students, will build outdoor growth chambers spanning a range of different temperatures. These chambers will allow students to observe firsthand how even small differences in temperature can have dramatic effects on plant growth and yield. Little is known about stomatal responses to temperature, although it is well-documented that temperature affects stomata indirectly via the leaf-to-air vapor pressure difference (VPDleaf). VPDleaf increases rapidly as leaves warm due to rising saturation vapor pressure in the leaf airspaces, causing stomata to close. But the direct response of stomata to temperature (DRST) – the response to temperature when VPDleaf is held constant – has rarely been reported for intact leaves, leaving the underlying mechanisms and ecological diversity largely unknown. Lack of knowledge of the DRST may skew models of carbon and water flux, preventing accurate prediction and understanding of plant function in a warming world. This study will quantify the DRST and its acclimation to growth temperature in species spanning the world's major functional types and ecosystems, plus 10 species and cultivars from a diverse, cosmopolitan clade (the genus Vitis); test predicted adaptive, biogeographic, and evolutionary trends in the DRST; test major hypothetical mechanisms for the DRST and use the results to refine a mechanistic model of stomatal conductance; and apply the resulting knowledge to a functional-structural 3D canopy model to quantify how the DRST affects integrated carbon and water fluxes at a range of time scales.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

植物提供陆地生命所需的所有能量，从空气中吸收二氧化碳，并利用太阳能将其转化为糖。在这个过程中，水分从叶子中蒸发。事实上，大部分以雨的形式落下的福尔斯水在从树叶中蒸发后又回到了大气中。了解植物如何调节水分流失是至关重要的，既要确定哪些基因控制这种调节，以便育种者能够提高作物水分利用效率，也要准确预测天气和气候波动将如何影响作物，牧场和森林的水分流失。植物通过打开和关闭叶子表面的气孔来调节水分流失--例如，它们在阳光下打开，在土壤干燥时关闭。然而，人们对温度变化如何影响这些孔隙知之甚少。这项研究将确定60个物种的影响，选择代表地球上最主要的栖息地;测试所发现的任何温度反应的生物原因的假设;并将这些发现纳入计算机模型，以预测温度反应如何影响植物生长和水分流失。除了对本科生和研究生进行现代实验植物生物学的培训外，还将开发一个体验项目，其中来自附近一所高中的学生将建造一系列不同温度的室外生长室。这些温室将使学生能够直接观察到即使是微小的温度差异也会对植物生长和产量产生巨大影响。气孔对温度的反应知之甚少，尽管有充分的证据表明温度通过叶片与空气的蒸气压差（VPDleaf）间接影响气孔。VPD叶迅速增加，因为叶片温暖，由于上升的饱和蒸汽压在叶气隙，导致气孔关闭。但气孔对温度的直接反应（DRST）-当VPD叶保持恒定时对温度的反应-很少有完整叶片的报道，留下的潜在机制和生态多样性在很大程度上未知。缺乏对DRST的了解可能会扭曲碳和水通量的模型，从而无法准确预测和理解变暖世界中的植物功能。本研究将量化DRST及其对世界主要功能类型和生态系统的物种生长温度的适应，以及来自不同的世界性分支的10个物种和品种（属葡萄属）;测试预测的适应性，地理，和进化趋势的DRST;测试主要假设机制的DRST和使用的结果，以完善气孔导度的机械模型;该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。