Potassium supply modulates Eucalyptus leaf water-status under PEG-induced osmotic stress: integrating leaf gas exchange, carbon and nitrogen isotopic composition and plant growth.

Autor: de Souza Mateus N; Center for Nuclear Energy in Agriculture, University of São Paulo, São Paulo 13400-970, Brazil., Oliveira Ferreira EV; Amazon Rural Federal University, Pará 68650-000, Brazil., Florentino AL; University of São Paulo, Luiz de Queiroz College of Agriculture, São Paulo 13418-900, Brazil., Vicente Ferraz A; Forest Science and Research Institute, IPEF, São Paulo 13415-000, Brazil., Domec JC; ISPA Bordeaux Sciences Agro UMR 1391, INRA, 33140 Villenave d'Ornon, France., Jordan-Meille L; ISPA Bordeaux Sciences Agro UMR 1391, INRA, 33140 Villenave d'Ornon, France., Bendassolli JA; Center for Nuclear Energy in Agriculture, University of São Paulo, São Paulo 13400-970, Brazil., Moraes Gonçalves JL; University of São Paulo, Luiz de Queiroz College of Agriculture, São Paulo 13418-900, Brazil., Lavres J; Center for Nuclear Energy in Agriculture, University of São Paulo, São Paulo 13400-970, Brazil.
Jazyk: angličtina
Zdroj: Tree physiology [Tree Physiol] 2022 Jan 05; Vol. 42 (1), pp. 59-70.
DOI: 10.1093/treephys/tpab095
Abstrakt: The objective of this study was to quantify the effect of potassium (K) supply on osmotic adjustment and drought avoidance mechanisms of Eucalyptus seedlings growing under short-term water stress. The effects of K supply on plant growth, nutritional status, leaf gas exchange parameters, leaf water potential (Ψw), leaf area (LA), stomatal density (SD), leaf carbon (C) and nitrogen (N) isotopic compositions (δ13C and δ15N ‰) and leaf C/N ratio under polyethylene glycol (PEG)-induced water deficit were measured. Under both control (non-PEG) and osmotic stress (+PEG) conditions, K supply increased plant growth, boosting dry matter yield with decreased C/N leaf ratio and δ15N ‰ values. The +PEG significantly reduced LA, plant growth, dry matter yield, Ψw, number of stomata per plant and leaf gas exchange, relative to non-PEG condition. Potassium supply alleviated osmotic-induced alterations in Eucalyptus seedlings by better regulating leaf development as well as SD, thus improving the rate of leaf gas exchange parameters, mesophyll conductance to CO2 (lower δ13C ‰ values) and water use efficiency (WUE). Consequently, K-supplied plants under drought better acclimated to osmotic stress than K-deficient plants, which in turn induced lower CO2 assimilation and dry matter yield, as well as higher leaf δ13C ‰ and δ15N ‰ values. In conclusion, management practices should seek to optimize K-nutrition to improve WUE, photosynthesis-related parameters and plant growth under water deficit conditions.
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Databáze: MEDLINE
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