Data/hora: 02/06/2024 05:13:57

Provedor de dados: | 63
País: | Brazil
Título: | Stomatal behavior and components of the antioxidative system in coffee plants under water stress
Autores: | Deuner,Sidnei; Alves,José Donizeti; Zanandrea,Ilisandra; Goulart,Patrícia de Fátima Pereira; Silveira,Neidiquele Maria; Henrique,Paôla de Castro; Mesquita,Alessandro Carlos.
Data: | 2011-02-01
Ano: | 2011
Palavras-chave: | Coffea arabica; Oxidative stress; Antioxidants; Water stress.
Resumo: | Coffee (Coffea arabica) plants show a positive relationship between stomatal closure and formation and accumulation of H2O2. However, for coffee plants under water restriction such relationship has never been studied. The objective of the present study was evaluate the stomatal movement and the antioxidant capacity of coffee seedlings under different water regimes. Eight months old coffee seedlings of cv. Catuaí IAC 99 were submitted to field capacity, gradual and total suspension of irrigation during a period of 21 days. Evaluations of leaf water potential (Ψw) were performed in the beginning of the morning, and stomatal resistance, transpiration rate and vapor pressure deficit were determined at 10 am and 5 pm. All biochemical and enzymatic determinations were performed in leaves collected at 5 pm. Evaluations and samplings were performed at three days intervals. There was no variation in Ψw during the evaluated period for plants in field capacity. However, an expressive decrease of Ψw following day 12, reaching values near -2.5 MPa at the end of the experiment was observed for plants submitted to gradual suspension of irrigation. For plants submitted to total suspension of irrigation, Ψw decreases after the sixth day, reaching -2.5 MPa at day 15. The decay of Ψw in plants submitted to gradual and total suspension of irrigation reflected in increased stomatal resistance and in a decreased transpiration rate leading to an increase in hydrogen peroxide formation and, on final stages, increase in lipid peroxidation. As a conclusion, an increase in the activity of antioxidant enzymes as well as in the levels of ascorbate and dehydroascorbate was observed, which act in the detoxification of free radicals formed as result of the water stress.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162011000100012
Editor: | São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Relação: | 10.1590/S0103-90162011000100012
Formato: | text/html
Fonte: | Scientia Agricola  v.68 n.1 2011
Fonte: | info:eu-repo/semantics/openAccess