土壤干旱胁迫对柔毛淫羊藿膜脂过氧化作用和保护酶活性的影响  

Effect of Soil Drught Stress on Membrane Lipid Peroxidation and Activity of Cell Defense Enzymes in Leaves of Epimedium Pubescens Maxim

作　　者：童雅赟[1] 黎云祥[1] 权秋梅[1] 杨艳[1] 王辉[1] 赵刚[1] 

机构地区：[1]西华师范大学西南野生动植物资源保护教育部重点实验室,四川南充637009

出　　处：《西华师范大学学报（自然科学版）》2010年第3期229-234,共6页Journal of China West Normal University(Natural Sciences)

基　　金：四川省教育厅项目(09ZX011);四川省科技厅应用基础研究项目(2008JY0158);省部共建教育部重点实验室开放基金项目(XNYB09-04)

摘　　要：采取盆栽控水法模拟了4种土壤水分状态:正常浇水(T1)、轻度干旱胁迫(T2)、中度干旱胁迫(T3)、重度干旱胁迫(T4),测定了上述不同程度土壤干旱胁迫条件下柔毛淫羊藿(Epimedium pubescens Maxim.)的丙二醛含量(MDA)、叶片相对含水量(RWC)、质膜相对透性(RC)以及超氧化物岐化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)的活性.RWC随着土壤干旱程度的加剧而上升,但在各种胁迫条件下却均保持在70%以上.轻度干旱胁迫下SOD、CAT和POD酶活性显著上升,但MDA含量和RC却只是轻微上升;中度干旱胁迫下SOD、CAT、POD酶活性、MDA含量和RC均显著上升;重度干旱胁迫下RC继续显著上升,MDA含量和POD酶活性轻微上升,而SOD、CAT酶活性却显著下降.试验结果表明柔毛淫羊藿有较强的保水能力.植株可以通过提高保护酶的活性抑制膜脂过氧化作用,维持膜系统的稳定.在轻度土壤干旱胁迫条件下,这种保护作用是积极有效的,但干旱胁迫的加剧削弱了这种保护作用,中度干旱胁迫下膜脂过氧化作用加剧,质膜开始受损.重度干旱胁迫下SOD、CAT酶活性下降,膜系统进一步受损.In our study,Epimedium pubescens Maxim.was subjected to different soil drought stress by using pot culture experiments simulating four kinds of soil water： no drought stress（T1）,mild drought stress（T2）,moderate drought stress（T3） and severe drought stress（T4）.Relative water content（RWC）,malondialdehyde（MDA） content,cell membrane permeability（RC）,as well as activities of superoxide dismutase（SOD）,catalase（CAT） and peroxidase（POD） in leaves of E.pubescens were tested.We find that RWC decreased along with aggravation of soil drought stress and maintained above 70% under all kinds of stress.Mild drought stress significantly increased activities of SOD,CAT and POD,but increased little in MDA content and RC.Moderate drought stress significantly promoted activities of SOD,CAT and POD,as well as MDA content and RC.Under severe drought stress,RC continuously increased significantly,MDA content,POD activity increased little,SOD and CAT activities decreased significantly.Our results indicated that E.pubescens may keep water under soil drought stress.Plants inhibit membrane lipid peroxidation and maintain the stability of membrane system by increasing activities of cell defense enzymes,but this effct is effectual under mild soil drought stress.However,this protection would be weakened by aggravation of soil drought stress,membrane lipid peroxidation intensfy and stability of membrane system decrease under moderate drought stress.At last,SOD and CAT activities decrease under severe drought stress,and membrane system would suffer more serious damage.

关 键 词：柔毛淫羊藿 土壤干旱胁迫 叶片相对含水量 膜脂过氧化作用 保护酶 

分 类 号：Q945.17[生物学—植物学]