{"title":"隐喻电路的短路:在叶片气体交换的欧姆类比中,维管分区和气孔斑块会造成明显的不饱和和二氧化碳梯度反转。","authors":"Fulton E. Rockwell","doi":"10.1111/nph.20106","DOIUrl":null,"url":null,"abstract":"<div>\n \n <p>\n \n </p><ul>\n \n \n <li>Analyses of leaf gas exchange rely on an Ohmic analogy that arrays single stomatal, internal air space, and mesophyll conductances in series. Such models underlie inferences of mesophyll conductance and the relative humidity of leaf airspaces, reported to fall as low as 80%. An unresolved question is whether such series models are biased with respect to real leaves, whose internal air spaces are chambered at various scales by vasculature.</li>\n \n \n <li>To test whether unsaturation could emerge from modeling artifacts, we compared series model estimates with true parameter values for a chambered leaf with varying distributions and magnitudes of leaf surface conductance (‘patchiness’).</li>\n \n \n <li>Distributions of surface conductance can create large biases in gas exchange calculations. Both apparent unsaturation and internal CO<sub>2</sub> gradient inversion can be produced by the evolution of broader distributions of stomatal apertures consistent with a decrease in surface conductance, as might occur under increasing vapor pressure deficit.</li>\n \n \n <li>In gas exchange experiments, the behaviors of derived quantities defined by simple series models are highly sensitive to the true partitioning of flux and stomatal apertures across leaf surfaces. New methods are needed to disentangle model artifacts from real biological responses.</li>\n </ul>\n \n </div>","PeriodicalId":214,"journal":{"name":"New Phytologist","volume":"244 5","pages":"1812-1823"},"PeriodicalIF":8.3000,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Shorting the metaphorical circuit: vascular partitioning and stomatal patchiness can create apparent unsaturation and CO2 gradient inversion in the Ohmic analogy for leaf gas exchange\",\"authors\":\"Fulton E. Rockwell\",\"doi\":\"10.1111/nph.20106\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div>\\n \\n <p>\\n \\n </p><ul>\\n \\n \\n <li>Analyses of leaf gas exchange rely on an Ohmic analogy that arrays single stomatal, internal air space, and mesophyll conductances in series. Such models underlie inferences of mesophyll conductance and the relative humidity of leaf airspaces, reported to fall as low as 80%. An unresolved question is whether such series models are biased with respect to real leaves, whose internal air spaces are chambered at various scales by vasculature.</li>\\n \\n \\n <li>To test whether unsaturation could emerge from modeling artifacts, we compared series model estimates with true parameter values for a chambered leaf with varying distributions and magnitudes of leaf surface conductance (‘patchiness’).</li>\\n \\n \\n <li>Distributions of surface conductance can create large biases in gas exchange calculations. Both apparent unsaturation and internal CO<sub>2</sub> gradient inversion can be produced by the evolution of broader distributions of stomatal apertures consistent with a decrease in surface conductance, as might occur under increasing vapor pressure deficit.</li>\\n \\n \\n <li>In gas exchange experiments, the behaviors of derived quantities defined by simple series models are highly sensitive to the true partitioning of flux and stomatal apertures across leaf surfaces. New methods are needed to disentangle model artifacts from real biological responses.</li>\\n </ul>\\n \\n </div>\",\"PeriodicalId\":214,\"journal\":{\"name\":\"New Phytologist\",\"volume\":\"244 5\",\"pages\":\"1812-1823\"},\"PeriodicalIF\":8.3000,\"publicationDate\":\"2024-09-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"New Phytologist\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1111/nph.20106\",\"RegionNum\":1,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"PLANT SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"New Phytologist","FirstCategoryId":"99","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/nph.20106","RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PLANT SCIENCES","Score":null,"Total":0}
Shorting the metaphorical circuit: vascular partitioning and stomatal patchiness can create apparent unsaturation and CO2 gradient inversion in the Ohmic analogy for leaf gas exchange
Analyses of leaf gas exchange rely on an Ohmic analogy that arrays single stomatal, internal air space, and mesophyll conductances in series. Such models underlie inferences of mesophyll conductance and the relative humidity of leaf airspaces, reported to fall as low as 80%. An unresolved question is whether such series models are biased with respect to real leaves, whose internal air spaces are chambered at various scales by vasculature.
To test whether unsaturation could emerge from modeling artifacts, we compared series model estimates with true parameter values for a chambered leaf with varying distributions and magnitudes of leaf surface conductance (‘patchiness’).
Distributions of surface conductance can create large biases in gas exchange calculations. Both apparent unsaturation and internal CO2 gradient inversion can be produced by the evolution of broader distributions of stomatal apertures consistent with a decrease in surface conductance, as might occur under increasing vapor pressure deficit.
In gas exchange experiments, the behaviors of derived quantities defined by simple series models are highly sensitive to the true partitioning of flux and stomatal apertures across leaf surfaces. New methods are needed to disentangle model artifacts from real biological responses.
期刊介绍:
New Phytologist is an international electronic journal published 24 times a year. It is owned by the New Phytologist Foundation, a non-profit-making charitable organization dedicated to promoting plant science. The journal publishes excellent, novel, rigorous, and timely research and scholarship in plant science and its applications. The articles cover topics in five sections: Physiology & Development, Environment, Interaction, Evolution, and Transformative Plant Biotechnology. These sections encompass intracellular processes, global environmental change, and encourage cross-disciplinary approaches. The journal recognizes the use of techniques from molecular and cell biology, functional genomics, modeling, and system-based approaches in plant science. Abstracting and Indexing Information for New Phytologist includes Academic Search, AgBiotech News & Information, Agroforestry Abstracts, Biochemistry & Biophysics Citation Index, Botanical Pesticides, CAB Abstracts®, Environment Index, Global Health, and Plant Breeding Abstracts, and others.