Effect of cold acclimation on the lipid composition of the inner and outer membrane of the chloroplast envelope isolated from rye leaves.

摘要

The lipid composition of the inner and outer membranes of the chloroplast envelope isolated from winter rye (Secale cereale) cv. Puma leaves was characterized before and after cold acclimatization at dayight temperatures of 13/7鳦 for 1 week followed by 2鳦 for 4 weeks. In nonacclimatized leaves the inner membrane contained high proportions of monogalactosyldiacylglycerols (MGDG, 47.9 mol% of the total lipids) and digalactosyldiacylglycerols (DGDG, 31.1 mol%) and a low proportion of phosphatidylcholine (PC, 8.1 mol%). The outer membrane contained a similar proportion of DGDG (30.0 mol%); however, the proportion of MGDG was much lower (20.1 mol%) and the proportion of PC was much higher (31.5 mol%). After 4 weeks of cold acclimatization, the proportions of these lipid classes were significantly altered in both of the inner and outer membranes. In the inner membrane the proportion of MGDG decreased (from 47.9 to 38.4 mol%) and the proportion of DGDG increased (from 31.1 to 39.3 mol%), with only aslight change in the proportion of PC (from 8.1 to 8.8 mol%). In the outer membrane MGDG decreased from 20.1 to 14.8 mol%, DGDG increased from 30.0 to 39.9 mol%, and PC decreased from 31.5 to 25.4 mol%. Thus, both before and after cold acclimatization,the proportion of MGDG was much higher in the inner membrane than in the outer membrane. In contrast, the proportion of PC was higher in the outer membrane than in the inner membrane.