Do stomata optimize turgor-driven growth?: A new framework for integrating stomata response with whole-plant hydraulics and carbon balance

编号 040037802

推送时间 20230116

研究领域 森林培育 

年份 2022 

类型 期刊 

语种 英语

标题 Do stomata optimize turgor-driven growth?: A new framework for integrating stomata response with whole-plant hydraulics and carbon balance

来源期刊 The New phytologist

期 第378期

发表时间 20221114

关键词 dynamic optimality;  nonstructural carbohydrates;  source-sink dynamics;  stomatal optimization;  tree growth;  tree hydraulics;  turgor-driven expansion.; 

摘要 Every existing optimal stomatal model uses photosynthetic carbon assimilation as a proxy for plant evolutionary fitness. However, assimilation and growth are often decoupled, making assimilation less ideal for representing fitness when optimizing stomatal conductance to water vapor and carbon dioxide. Instead, growth should be considered a closer proxy for fitness. We hypothesize stomata have evolved to maximize turgor-driven growth, instead of assimilation, over entire plants' lifetimes, improving their abilities to compete and reproduce. We develop a stomata model that dynamically maximizes whole-stem growth following principles from turgor-driven growth models. Stomata open to assimilate carbohydrates that supply growth and osmotically generate turgor, while stomata close to prevent losses of turgor and growth due to negative water potentials. In steady-state, the growth-optimization model captures realistic stomatal, growth, and carbohydrate responses to environmental cues, reconciles conflicting interpretations within existing stomata optimization theories, and explains patterns of carbohydrate storage and xylem conductance observed during and after drought. Our growth-optimization hypothesis introduces a new paradigm for stomata optimization models, elevates the role of whole-plant carbon-use and carbon storage in stomatal functioning, and has the potential to simultaneously predict gross productivity, net productivity, and plant mortality through a single, consistent modeling framework.

服务人员 孙小满

服务院士 尹伟伦

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