In situ and in vitro senescence induced by KCl stress: nutritional imbalance, lipid peroxidation and antioxidant metabolism

• Tipo: Artigo em Revista Científica Internacional
• Data: 2001

Autores

Santos, CLV (Autor) Outra; Alexandre Campos (Autor) Outra; Azevedo, H (Autor) Outra; Caldeira, G (Autor) Outra

Revista

Título: Journal of Experimental Botany

Vol. 52

Páginas: 351-360

ISSN: 0022-0957

Editora: Oxford University Press

Indexação

ISI Web of Knowledge - 121 Citações

Scopus - 148 Citações

Outras Informações

ID Authenticus: P-000-WHA

DOI: 10.1093/jexbot/52.355.351

Abstract (EN): Sunflower (Helianthus annuus L, cv, SH222) plants and calli were exposed to KCl stress for three weeks. Calli were more tolerant to KCl than plants. KCl stress decreased NO3- Mn, Fe and B levels in whole plants and P, Ca and Mg in shoots. NO3-, P, Ca, Mg, Mn, and B levels decreased in 100 mM-stressed calli, Chlorophyll content, F-m and (F-m-F-0)/F-m ratio decreased in stressed leaves, while F-0 increased only in leaves exposed to severe stress (100 and 150 mM), Membrane permeability and lipid peroxidation increased in plants under all stress conditions and in 100 and 150 mM stressed calli, but remained unchanged in 25 mM stressed calli, Salt stress also induced changes relating to antioxidant enzymes: plants under all stress conditions showed a decrease in catalase, peroxidase and SOD activities. Calli under moderate stress (25 mM KCl) showed an increase of catalase, peroxidase and SOD activities, but the activities of peroxidase and SOD decreased when calli were exposed to higher KCl concentrations. The decrease of antioxidant enzyme activities is in tune with lipid peroxidation and membrane permeability increases. On the other hand, calli adapted for 6 months to 100 mM KCl showed an increase of these enzyme activities compared to unstressed calli, while MDA production and membrane permeability were not significantly affected.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10