Enhancing potassium content in leaves and stems improves drought tolerance of eucalyptus clones

Autor(es)

Santos, Elcio Ferreira ^[1] ; Mateus, Nikolas Souza ^[2] ; Rosario, Mayk Oliveira ^[3] ; Garcez, Tiago Barreto ^[3] ; Mazzafera, Paulo ^{[4, 5]} ; Lavres, Jose ^[2]

Afiliação do(s) autor(es)

^[1] Fed Inst Mato Grosso Sul, Lab Plant Nutr, BR-7575000 Nova Andradina, MS - Brazil

^[2] Univ Sao Paulo, Ctr Nucl Energy Agr, Piracicaba - Brazil

^[3] Univ Fed Sergipe, Campus Sertao, Nossa Senhora Da Gloria - Brazil

^[4] Univ Estadual Campinas, Inst Biol, Campinas - Brazil

^[5] Univ Sao Paulo, Luiz Queiroz Coll Agr, Piracicaba - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PHYSIOLOGIA PLANTARUM; v. 172, n. 2 OCT 2020.
• Citações Web of Science: 5

Resumo

Eucalyptus are widely planted in regions with low rainfall, occasioning frequent drought stresses. To alleviate the stress-induced effects on plants growing in these environments, soil fertilization with potassium (K) may affect drought-adaptive plant mechanisms, notably on tropical soils with low K availability. This work aimed to evaluate the K dynamic nutrition in eucalyptus in response to soil-K and -water availabilities, correlating the K-nutritional status with the physiological responses of contrasting eucalyptus clones to drought tolerance. A complete randomized design was used to investigate the effects of three water regimes (well-watered, moderate water deficit, and severe water deficit) and two K soil supplies (sufficient and low K) on growth and physiological responses of two elite eucalyptus clones: ``VM01{''} (Eucalyptus urophylla x camaldulensis) and ``AEC 0144{''} (E. urophylla). Results depicted that the K-well-nourished E. urophylla x camaldulensis clone under severe water deficit maintained shoot biomass accumulation by upregulating the K-content in leaves and stems, gas exchange, water-use efficiency (WUEI), leaf water potential (psi w), and chlorophyll a fluorescence parameters, compared to E. urophylla clone. Meanwhile, E. urophylla with a severe water deficit showed a decreased of K content in leaves and stem, as well as a reduction in the accumulation of dry mass. Therefore, the K-use efficiency and the apparent electron transport rate through photosystem II were positively correlated in plants grown in low K, indicating the importance of K in maintaining leaf photochemical processes. In conclusion, management strategy should seek to enhance K-nutrition to optimize water-use efficiencies and photosynthesis. (AU)

• Processo FAPESP: 17/23590-9 - Remobilização do potássio no eucalipto em resposta ao estresse hídrico
• Beneficiário: Elcio Ferreira dos Santos
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado