杂交稻幼苗经聚乙二醇(PEG4000)渗透胁迫(-0.8MPa)处理,秧苗体内超氧化物歧化酶(SOD)和过氧化物酶(POD)活性降低,谷胱甘肽(GSH)和抗坏血酸(ASA)含量下降,丙二醛(MDA)含量升高,膜透性增大;随着渗透胁迫处理时间延长,幼苗膜脂饱和脂肪酸增加,不饱和脂肪酸含量降低,不饱和脂肪酸指数(IUFA)减小.在同样胁迫条件下,用8 mmol/L Vc进行根际预处理,能减轻因PEG渗透胁迫诱导造成的秧苗膜脂过氧化作用.
The change of the activities of superoxide dismutase (SOD), peroxidase (POD) and the contents of glutathione (GSH), ascorbic acid(ASA), malondialdehyde (MDA) and the relative permeability of plasma membrane, fatty acid composition(mol%) in the seedlings of hybrid rice were studied under osmotic stress (-0.8 MPa). The results showed that the MDA content and the permeability of plasma membrane increased sharply, but the activities of SOD and POD and the contents of GSH and ASA decreased markedly, the index of unsaturated fatty acids (IUFA) in membrane lipid of seedlings decreased with the duration of treatment of osmotic stress increased. However, when seedlings pre treated by soaking the roots with Vc, the MDA content and permeability of plasma membrane in seedlings decreased, but the POD and SOD activity, GSH and ASA content, the IUFA value increased, which indicates that Vc can alleviate the damage of the peroxidization of membrane lipid to seedlings by induction of PEG.
membrane lipid peroxidation
index of unsaturated fatty acid (IUFA)