Lipid Transformations in Plastids of Bean Leaves and Pepper Fruits

Abstract

Plastids were isolated from 2 tissues in which plastid breakdown may have occurred - mature green leaves placed in continuous darkness and ripening pepper fruits. For comparison the plastid lipids of leaves subjected to 3 different lengths of darkness and plastid lipids from pepper fruits at 3 stages of maturity were extracted following plastid isolation. Lipids were separated by silicic acid column, silicic acid-impregnated paper, and gas-liquid chromatography. Analyses were made for P, sugars, and fatty acids. Plastids subjected to long periods of darkness and those from red pepper fruits contained relatively less monogalactosyl glycerol-lipids as compared to light-treated plastids and plastids from green fruits. Increased dark treatment, generally, caused an increase in the ratio of saturated to unsaturated fatty acids, whereas plastids from red and green peppers had the same ratio of saturated to unsaturated fatty acids.