Cambios en actividad triosa-fosfato isomerasa y estudio de su posible pérdida por cloroplastos durante el envejecimiento de hojas
- Cuello Moreno, Juan
- Quiles Ródenas, María José de Jesús
- Sabater García, Bartolomé
ISSN: 1138-3399, 1989-2128
Year of publication: 1988
Issue: 15
Pages: 169-176
Type: Article
More publications in: Anales de biología
Abstract
We have studied the relative changes of triose-phosphate isomerase (TIM) in cytoplasm and chloroplasts during the senescence of primary barley leaves. The subcellular fractions were isolated by equillibrium ultracentrifugation in a density sucrose gradient. Cytoplasmic glucose-6-phosphate dehydrogenase and TIM activities diminished during senescence and their loss was retarded by kinetin. TIM activity was relatively low in chloroplasts. The presence of TIM activity between chloroplast and cytoplasm ultracentrifugation fractions suggested that TIM activity was lost from broken chloroplasts. However, we do not find in senescent leaves any factor stimulating chloroplasts breakdown.