NaCl胁迫下星星草幼苗MDA含量与膜透性及叶绿素荧光参数之间的关系  

Relationships among MDA content,plasma membrane permeability and the chlorophyll fluorescence parameters of Puccinellia tenuiflora seedlings under NaCl stress

作　　者：汪月霞[1] 孙国荣[1] 王建波[1] 曹文钟[2] 梁建生[1] 余政哲[3] 陆兆华[4] 

机构地区：[1]扬州大学生物科学与技术学院 [2]大庆石油学院化学化工学院,大庆163318 [3]中国科学院生态环境研究中心,北京100085 [4]中国矿业大学恢复生态学研究所,北京100083

出　　处：《生态学报》2006年第1期122-129,共8页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目(30270234)~~

摘　　要：星星草幼苗在不同浓度NaCl胁迫处理7d后，测定了叶绿索荧光参数、MDA含量和叶片电解质外渗率。结果表明，在低浓度NaCl（小于1．2％）胁迫下，星星草幼苗叶绿体MDA含量随胁迫强度的增强而降低，而在高浓度NaCl（1．2％～2．4％）胁迫下则相反。在低浓度NaCl（小于1．2％）胁迫下，Fv/Fm（PsⅡ原初光能转化效率）、Fv/Fo（表PSⅡ潜在活性）、Fv’/Fm’（类囊体能化时PSⅡ固有效率）和护（荧光光化学淬灭效率）随着胁迫强度的增强而增高，而在高浓度NaCl（1．2％～2．4％）胁迫下则随着胁迫强度的增强而降低；而qNP（荧光非光化学淬灭效率）和HDR（热耗散速率）却随着胁迫强度的增强而增高。φAPSⅡ（PSⅡ实际光化学效率）在低浓度NaCl（小于0．4％）胁迫下随着胁迫强度增强而升高，在0．4％-1．6％之间迅速下降，大于1．6％时，φPSⅡ又迅速升高。Fv/Fm，Fv/Fo，Fv’/Tm/和qP均随着MDA含量的增高而降低，而EL（叶片电解质外渗率）、qNP和HDR在MDA含景较低的范围（0．9753-1．1901μmol·g^-1 FW）内均减小，在MDA含量较高的范围（1．3080—1．8518μmol·g^-1 FW）内，均迅速增大。中PSⅡ在MDA含量较低范围（0．9753～1．0953μmol·g^-1 FW）内时上升，但变化不大，随着MDA含量的增高（在1．1172—1．1901μmol·g^-1FW）范围内迅速降低，但当MDA含量进一步增高时（在1．3080～1．8518μmol·g^-1 FW）范围内叉迅速升高。这些结果表明，星星草幼苗的荧光参数具体的变化规律与盐胁迫强度和幼苗细胞膜的受损伤程度密切相关，即低浓度NaCl胁迫（小于1．2％）下，星星草幼苗由于活性氧的增加而发生膜脂过氧化可能主要通过体内较高活性的保护酶系统来清除，而高浓度NaCl胁迫（大于1．2％）下，星星草幼苗可能具有与其它植物不同的保护机制，即可能主要通过增加qNP（荧光非光In order to study the mathematic relationship between changes of the chlorophyll fluorescence parameters of P. tenuiflora seedlings and the fine regulation mechanism of metabolism of cell membrane stability under salt stress, electrolyte leakage rate （ EL ） using relatively electrical conductivity method and malondialdehyde （MDA） content using the thiobarbituric acid method relating to cell membrane stability were determined as the variable of physiological parameters that could reflect the status of physiological system or injury extent by stress, and the fluorescence parameters such as Fv/Fm, Fv/Fo, qP, Fv＇/Fm＇, φDPⅡ , HDR and qNP were also determined by the method of fluorescence induction kinetics with FMS2- facilitative Fluorescence Monitoring System under normal condition and different degrees of NaCl stress （0.4%, 0.8% ,1.2% ,1.6% ,2% ,2.4%） after 7d.The result showed that MDA content decreased a little under low NaCl stress （less than 1.2% ）, then increased significantly with increasingof NaCl concentration （ more than 1.2 % ）. Among the chlorophyll fluorescence parameters, Fv/Fo, Fv/Fm, Fv＇ / Fm＇ and qP took a similar trend of increasing firstly then decreasing with the increasing of NaCl concentration, but qNP and HDR increased with the increasing of NaCl concentration accordingly. At the same time, φPS Ⅱ increased slightly under low NaCl stress（less than 0.4% ）, then decreased significantly, finally increased fastly. The result also showed that with increases in MDA content, Fv/Fo, Fv/Fm, qP and Fv＇/Fm＇ decreased accordingly, however, EL decreased slightly firstly in MDA content（0.9753 ～ 1. 190μmol· g^-1 FW）, then increased significantly with the increasing of MDA content（1.3080 - 1.8518μmol·g^-1FW）, showing the similar trend of qNP and HDR. On the other hand, φPS Ⅱ displayed ascending trend during MDA content （0.9753 - 1.0953μmol·g^-1 FW）, then showed descending trend during MDA content （1.1172 - 1. 1901μmol· g^-1 FW）, finally inc

关 键 词：星星草 盐胁迫 MDA含量 电解质外谱率 叶绿素 荧光参数 

分 类 号：Q945.78[生物学—植物学]