Leaf C-13 and N-15 composition shedding light on easing drought stress through partial K substitution by Na in eucalyptus species

Author(s)

Mateus, Nikolas Souza ^[1] ; Florentino, Antonio Leite ^[2] ; Oliveira, Jessica Bezerra ^[1] ; Santos, Elcio Ferreira ^[1] ; Gaziola, Salete Aparecida ^[2] ; Rossi, Monica Lanzoni ^[1] ; Linhares, Francisco Scaglia ^[1] ; Bendassolli, Jose Albertino ^[1] ; Azevedo, Ricardo Antunes ^[2] ; Lavres, Jose ^[1]

Affiliation

^[1] Univ Sao Paulo, Ctr Nucl Energy Agr, Ave Centenario, 303 CP 9, BR-13416000 Piracicaba - Brazil

^[2] Univ Sao Paulo, Coll Agr Luiz de Queiroz, BR-13418900 Piracicaba - Brazil

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 11, n. 1 OCT 11 2021.
• Web of Science Citations: 0

Abstract

This work aimed to investigate the partial K-replacement by Na supply to alleviate drought-induced stress in Eucalyptus species. Plant growth, leaf gas exchange parameters, water relations, oxidative stress (H2O2 and MDA content), chlorophyll concentration, carbon (C) and nitrogen (N) isotopic leaf composition (delta C-13 and delta N-15) were analyzed. Drought tolerant E. urophylla and E. camaldulensis showed positive responses to the partial K substitution by Na, with similar dry mass yields, stomatal density and total stomatal pore area relative to the well K-supplied plants under both water conditions, suggesting that 50% of the K requirements is pressing for physiological functions that is poorly substituted by Na. Furthermore, E. urophylla and E. camaldulensis up-regulated leaf gas exchanges, leading to enhanced long-term water use efficiency (WUEL). Moreover, the partial K substitution by Na had no effects on plants H2O2, MDA, delta C-13 and delta N-15, confirming that Na, to a certain extent, can effectively replace K in plants metabolism. Otherwise, the drought-sensitive E. saligna species was negatively affected by partial K replacement by Na, decreasing plants dry mass, even with up-regulated leaf gas exchange parameters. The exclusive Na-supplied plants showed K-deficient symptoms and lower growth, WUEL, and delta C-13, besides higher Na accumulation, delta N-15, H2O2 and MDA content. (AU)

• FAPESP's process: 17/24410-4 - Integrated effects of K and Na application on initial growth of eucalyptus seedlings submitted to water stress: water use efficiency, gas exchange and ´13C isotopic variation
• Grantee: Nikolas de Souza Mateus
• Support Opportunities: Scholarships in Brazil - Master