Accounting for mesophyll conductance substantially improves 13 C‐based estimates of intrinsic water‐use efficiency

Autor: Xiao Ying Gong, Xu Ming Wang, Hans Schnyder, Rudi Schäufele, Wei Ting Ma, Guillaume Tcherkez, Yusheng Yang
Přispěvatelé: College of Geographical Science, Fujian Normal University, Institut de Recherche en Horticulture et Semences (IRHS), Université d'Angers (UA)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), National Natural Science Foundation of China (NSFC) : NSFC 31870377, National Natural Science Foundation of Guangdong Province : 2018A030313450, German Research Foundation (DFG) : SCHN 557/7-1 : SCHN 557/9-1.
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: New Phytologist
New Phytologist, Wiley, 2021, 229 (3), pp.1326-1338. ⟨10.1111/nph.16958⟩
ISSN: 0028-646X
1469-8137
Popis: International audience; Carbon isotope discrimination (Delta) has been used widely to infer intrinsic water-use efficiency (iWUE) of C-3 plants, a key parameter linking carbon and water fluxes. Despite the essential role of mesophyll conductance (g(m)) in photosynthesis and Delta, its effect on Delta-based predictions of iWUE has generally been neglected.Here, we derive a mathematical expression of iWUE as a function of Delta that includes g(m) (iWUE(mes)) and exploits the g(m)-stomatal conductance (g(sc)) relationship across drought-stress levels and plant functional groups (deciduous or semideciduous woody, evergreen woody and herbaceous species) in a global database. iWUE(mes) was further validated with an independent dataset of online-Delta and CO2 and H2O gas exchange measurements with seven species.Drought stress reduced g(sc) and g(m) by nearly one-half across all plant functional groups, but had no significant effect on the g(sc) : g(m) ratio, with a well supported value of 0.79 +/- 0.07 (95% CI, n = 198). g(m) was negatively correlated to iWUE. Incorporating the g(sc) : g(m) ratio greatly improved estimates of iWUE, compared with calculations that assumed infinite g(m).The inclusion of the g(sc) : g(m) ratio, fixed at 0.79 when g(m) was unknown, proved desirable to eliminate significant errors in estimating iWUE from Delta across various C-3 vegetation types.
Databáze: OpenAIRE
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