水分胁迫与植物膜脂过氧化

水分胁迫使细胞活性氧代谢失调,O_2~·、OH~·、H_2O_2和~1O_2的积累超过膜伤害阈值,导致膜脂过氧化作用加剧,膜脂脂肪酸的配比发生变化,亚麻酸含量降低,MDA、乙烷等大量产生。保护酶系SOD,POD和CAT及抗氧化剂V_c、V_E、Car、GSH等可阻抑活性氧的积累,减轻膜伤害。水分胁迫下植物内源保护酶活性和抗氧化剂含量与膜脂过氧化水平有紧密的关系。

Water Stress and Membrane-Lipid Peroxidation in Plants

Water stress caused the imbalance of active oxygen metabolism in plant cells. The accumulation of O, OH, H2O2 and 'O2 could exceed injury threshold,thus,leading to an extensive membraae-lipid peroxidation and causing the change of fatty acid compositions in membrane-lipid. Linolenic acid content decreased, MDA and ethane were produced in large quantities. The protective enzyme systems (SOD, POD, and CAT) and antioxidants (Vc, VE, Car., GSH, etc.) can inhibit the accumulation of active oxygen and lessen membrane damage. Under water stress, there appeared to have a close correlation between the tissue ability to control lipid peroxidation and its ability to retain solutes.