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

Autor(es)

Mateus, Nikolas de Souza ^[1] ; Oliveira Ferreira, Eric Victor ^[2] ; Florentino, Antonio Leite ^[3] ; Ferraz, Alexandre Vicente ^[4] ; Domec, Jean-Christophe ^[5] ; Jordan-Meille, Lionel ^[5] ; Bendassolli, Jose Albertino ^[1] ; Moraes Goncalves, Jose Leonardo ^[3] ; Lavres, Jose ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Ctr Nucl Energy Agr, BR-13400970 Sao Paulo - Brazil

^[2] Amazon Rural Fed Univ, BR-68650000 Belem, Para - Brazil

^[3] Univ Sao Paulo, Luiz de Queiroz Coll Agr, BR-13418900 Sao Paulo - Brazil

^[4] Forest Sci & Res Inst, IPEF, BR-13415000 Sao Paulo - Brazil

^[5] INRA, ISPA Bordeaux Sci Agro UMR 1391, F-33140 Villenave Dornon - France

• Tipo de documento: Artigo Científico
• Fonte: TREE PHYSIOLOGY; v. 42, n. 1, p. 59-70, JAN 2022.
• Citações Web of Science: 0

Resumo

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 (Psi(w)), leaf area (LA), stomatal density (SD), leaf carbon (C) and nitrogen (N) isotopic compositions (delta C-13 and delta N-15 parts per thousand) 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 delta N-15 parts per thousand values. The +PEG significantly reduced LA, plant growth, dry matter yield, Psi(w), 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 delta C-13 parts per thousand 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 delta C-13 parts per thousand and delta N-15 parts per thousand values. In conclusion, management practices should seek to optimize K-nutrition to improve WUE, photosynthesis-related parameters and plant growth under water deficit conditions. (AU)

• Processo FAPESP: 14/16397-0 - Suprimento de potássio, sódio e silício às mudas de eucalipto
• Beneficiário: Nikolas de Souza Mateus
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica