逐渐干旱胁迫下生物土壤结皮中真藓和土生对齿藓的活性氧清除机制  

The Reactive Oxygen Species Scavenging Mechanism of Bryum argenteum and Didymodon vinealis in Biological Soil Crusts under Gradual Drought Stress

作　　者：石勇[1,2] 赵昕[1,2] 贾荣亮[2] 李新荣[1,2] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所植物逆境生理生态与生物工程实验室,甘肃兰州730000 [2]中国科学院寒区旱区环境与工程研究所沙坡头沙漠试验研究站,甘肃兰州730000

出　　处：《中国沙漠》2012年第3期683-690,共8页Journal of Desert Research

基　　金：国家自然科学基金项目(30770343;40825001)资助

摘　　要：真藓(Bryum argenteum)和土生对齿藓(Didymodon vinealis)是腾格里沙漠南缘沙坡头地区生物土壤结皮中重要的藓类植物组成成分。我们以真藓和土生对齿藓为材料,研究了逐渐干旱胁迫下两者的活性氧(ROS)清除机制及其差别。结果表明,逐渐干旱胁迫下,真藓的H2O2含量略微升高,丙二醛(MDA)含量显著下降,可溶性蛋白含量变化不大。在逐渐干旱胁迫下,真藓以过氧化氢酶(CAT)为主,超氧化物歧化酶(SOD)为辅,清除其体内活性氧自由基(ROS),抗坏血酸过氧化物酶(APX)和过氧化物酶(POD)作用不明显,而谷胱甘肽还原酶(GR)和还原性谷胱甘肽(GSH)则主要在中度干旱胁迫下起作用。逐渐干旱胁迫下,土生对齿藓的H2O2和MDA含量均显著上升,而可溶性蛋白含量显著下降。在逐渐干旱胁迫下,土生对齿藓以GSH为主,SOD、CAT为辅,清除其体内ROS,APX和GR的作用不明显,而POD则主要在中度干旱胁迫下起主要作用。Bryum argenteum and Didymodon vinealis are important components of sand-fixation biological soil crust in Shapotou region, south margin of Tengeer Desert. We studied the different reactive oxygen species （ROS） scavenging mechanisms of Bryum argenteum and Didymodon vinealis under gradual drought stress. Results showed that under gradual drought stress, Bryum argenteum＇s H202 content in- creased slightly, its malondialdehyde （MDA） content decreased significantly and soluble protein content changed slightly. Bryum argenteum scavenged its ROS mainly by catalase （CAT） and supplemented by su- peroxide dismutase （SOD） under gradual drought stress, while its ascorbate peroxidase （APX） and peroxi- dase （POD） didn＇t function a lot. However, glutathione reductase （GR） and glutathione （GSH） of Bryum argenteum played roles only under moderate drought stress. Under gradual drought stress, both H202 and MDA contents of Didymodon vinealis increased significantly, while its soluble protein content decreased sharply. Didymodon vinealis scavenged its ROS mainly by GSH under gradual drought stress and supple- mented by SOD and CAT, while its APX and GR didn＇t function a lot. However, its POD played a role only under moderate drought stress.

关 键 词：真藓 土生对齿藓 活性氧 逐渐干旱胁迫 

分 类 号：Q945.1[生物学—植物学]