Data/hora: 09/06/2024 16:47:27

Provedor de dados: | 61
País: | Brazil
Título: | Interactions between leaf water potential, stomatal conductance and abscisic acid content of orange trees submitted to drought stress
Autores: | Gomes,Mara de Menezes de Assis; Lagôa,Ana Maria Magalhães Andrade; Medina,Camilo Lázaro; Machado,Eduardo Caruso; Machado,Marcos Antônio.
Data: | 2004-12-01
Ano: | 2004
Palavras-chave: | Abscisic acid; Citrus sinensis; Gas exchanges; Water stress.
Resumo: | Thirty-month-old 'Pêra' orange trees grafted on 'Rangpur' lemon trees grown in 100 L pots were submitted to water stress by the suspension of irrigation. CO2 assimilation (A), transpiration (E) and stomatal conductance (g s) values declined from the seventh day of stress, although the leaf water potential at 6:00 a.m. (psipd) and at 2:00 p.m. (psi2) began to decline from the fifth day of water deficiency. The CO2 intercellular concentration (Ci) of water-stressed plants increased from the seventh day, reaching a maximum concentration on the day of most severe stress. The carboxylation efficiency, as revealed by the ratio A/Ci was low on this day and did not show the same values of non-stressed plants even after ten days of rewatering. After five days of rewatering only psi pd and psi2 were similar to control plants while A, E and g s were still different. When psi2 decreases, there was a trend for increasing abscisic acid (ABA) concentration in the leaves. Similarly, stomatal conductance was found to decrease as a function of decreasing psi2. ABA accumulation and stomatal closure occurred when psi2 was lower than -1.0 MPa. Water stress in 'Pera´ orange trees increased abscisic acid content with consequent stomatal closure and decreased psi2 values.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000300005
Editor: | Brazilian Journal of Plant Physiology
Relação: | 10.1590/S1677-04202004000300005
Formato: | text/html
Fonte: | Brazilian Journal of Plant Physiology  v.16 n.3 2004
Fonte: | info:eu-repo/semantics/openAccess