THE RELATIONSHIPS BETWEEN FREE PROLINE AND MEMBRANE LIPID PEROXIDATION IN RICE SEEDLINGS UNDER OSMOTIC STRESS

Seedlings of hybrid rice(Oryza sativa subsp. indica cv, Weiyou 287, Shanyou 287, Shanyou 63)were osmotic stress with polyethyleneglycol (PEG₄₀₀₀). The water content and relative water content of the rice seedlings were gradually decreased under osmotic stress(-0.95MPa), content of free proline and malondialdehyde(MDA)and permeability of plasma membrane increased sharply; however, there was a positive correlation of content of free proline with the level of membrane-lipid peroxidation. The response of the different hybrid rice combinations to osmotic stress was different. The index of unsaturated fatty acid (IUFA)in membrane lipids decreased treated by PEG.There was a negative relation between IUFAand content of free proline under osmotic stress.