Antioxidant capacity along the leaf blade of the C-3-CAM facultative bromeliad Guzmania monostachia under water deficit conditions

Autor(es)

Abreu, Maria E. ^[1] ; Carvalho, Victoria ^[2] ; Mercier, Helenice ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Biociencias, Dept Bot, BR-05508090 Sao Paulo, SP - Brazil

^[2] Inst Bot SMA SP, Nucleo Pesquisa Plantas Ornamentais, BR-04301902 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: FUNCTIONAL PLANT BIOLOGY; v. 45, n. 6, p. 620-629, 2018.
• Citações Web of Science: 1

Resumo

Guzmania monostachia (L.) Rusby ex Mez is an epiphytic, rosette-shaped bromeliad that displays variable degrees of crassulacean acid metabolism (CAM) along the leaf under water deficit. The aim of our study was to evaluate whether the production-scavenging system of reactive oxygen species (ROS) along the leaf length of G. monostachia plants is related to the foliar gradient of CAM when irrigation is withheld. Among the leaf portions, the apex was exposed to the highest photosynthetic flux density and presented the highest relative water content, CAM activity, hydrogen peroxide and lipid peroxidation after treatment. Hence, the most intense CAM at the leaf apex may not have prevented higher oxidative burden in that region during water deficiency. However, the photosynthetic efficiency in the apex seemed unaffected by irrigation withholding or light intensity. The leaf apex also had the highest carotenoid content and increased superoxide dismutase and ascorbate peroxidase activities under treatment. Hence, G. monostachia was able to maintain ROS under tolerable levels by increasing antioxidant capacity. Our results suggest the metabolic differences within the same leaf under water deficit may derive from the gradient of light incidence, which emphasises the physiological plasticity this bromeliad applies to adapt to the adverse conditions of the canopy. (AU)

• Processo FAPESP: 11/50637-0 - Competência para a expressão do metabolismo ácido das crassuláceas (CAM) em bromélia epífita: sinalização, modulação da expressão, perfil transcricional e interação com o metabolismo de nitrogênio
• Beneficiário: Helenice Mercier
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 14/03147-5 - ROS e antioxidantes em Guzmania monostachia: a indução do CAM é uma estratégia de defesa para amenizar o estresse oxidativo?
• Beneficiário: Maria Elizabeth Pereira de Abreu
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado