渗透胁迫对柠条叶片脂质过氧化及抗氧化酶活性的影响

采用PEG溶液对不同海拔下的柠条叶片进行渗透胁迫处理并对其生理响应进行了探讨.结果表明,在渗透胁迫下兰州市九州台山下的柠条叶片相对含水量、丙二醛含量和活性氧水平较低,脯氨酸含量较高,耐渗透胁迫的能力较强.SOD、POD和CAT三种抗氧化酶的活性在渗透胁迫下变化不一致,但总体表现为在轻度胁迫时升高,胁迫加重时下降的趋势.相关分析表明,渗透胁迫下柠条叶片各生理指标之间存在广泛的关联,说明多种因素影响柠条的抗旱性;相对含水量与脯氨酸含量显著负相关,与SOD活性呈显著正相关,说明叶片相对含水量低可能是其抗渗透胁迫能力较强的关键因素.

Effect of Osmotic Stress on Lipid Peroxidation and Antioxidant Enzyme Activity in Leaves of Caragana korshinskii

The physiological responses of Caragana korshinskii growing at different altitude to PEG os- motic stress were studied. The results showed that when the leaves of Caragana korshinskii were stressed, the material growing at the foot of Jiuzhou mountain had lower relative water content and MDA content, whereas higher proline content, and even a lower level of reactive oxygen than the material grow- ing on the top of the mountain. The above resuhs showed that the materials growing at the foot of the mountain had a better resistance to osmotic stress than the material growing on the top. The change in ac- tivities of three kinds of antioxidant enzymes (SOD, POD, CAT) differed, yet showed a trend of incre- ment in general when the stress lasted. The relationship analysis showed that the physiological indexes of the leaves under osmotic stress had a comprehensive interrelationship, it implied there were many factors affecting the drought resistance. The relationship analysis also showed that the relative water content had a sig- nificant negative relationship with the content of proline, and a significant positive relationship with the activity of SOD, it meant that lower water content in the leaves was the key factor for the resistance to osmotic stress.