Functional and structural changes in chloroplasts of senescent tobacco leaves

Abstract

The relationship between the structure and the function of chloroplasts of aging tobacco leaves was studied. From the observations of chloroplast structure in electron microscope, the results of other authors concerning earlier degradation of stroma lamellae in comparison with grana were confirmed. It was shown that this process is accompanied by changes in the content of galactolipids (in the first place MGDG) and earlier decomposition of chlorophyll-protein-complex I. This resulted in decrease of photosynthetic activity of leaves and earlier disappearance of Photosystem I activity.