不同干旱胁迫强度下白刺花幼苗叶片的生理生化反应  

Physiological and Biochemical Responses of Two-years-old Sophora davidii Seedling Leaves to Different Water Stresses

作　　者：王红梅[1,2] 包维楷[1] 李芳兰[1] 

机构地区：[1]中国科学院成都生物研究所,成都610041 [2]中国科学院研究生院,北京100049

出　　处：《应用与环境生物学报》2008年第6期757-762,共6页Chinese Journal of Applied and Environmental Biology

基　　金：中国科学院西部行动计划(二期)项目(No.KZCX2-XB2-02);“西部之光”计划博士基金项目(No.08C2041100)资助~~

摘　　要：植物代谢产物和抗氧化酶活性与干旱胁迫强度的定量关系是评估植物适应干旱能力的重要科学问题.本文采用盆栽试验设计,设置土壤田间持水量(FC)80%、60%、40%、20%4个干旱胁迫处理,研究了不同强度的干旱胁迫梯度上2a生白刺花(Sophora davidii)幼苗叶片内丙二醛(MDA)、脯氨酸(Pro)、可溶性蛋白质、光合色素含量、超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)、过氧化氢酶(CAT)和过氧化物酶(POD)活性的变化特点.发现:(1)MDA与Pro含量随着干旱胁迫强度的增加呈线性增加趋势.(2)蛋白质和光合色素含量在干旱胁迫梯度上呈"钟型"抛物线变化趋势,在60%～40%FC下含量最高.(3)4种抗氧化酶活性的变化趋势不尽相同.其中SOD与APX的活性在干旱胁迫梯度上的反应均表现为多项式变化规律,即在中度干旱下的活性显著升高,而重度胁迫下降低;CAT活性变化规律与SOD和APX活性的变化正好相反;POD活性则表现为倒钟型趋势,60%FC下活性最低.综合分析表明,可溶性蛋白质和光合色素的含量、SOD、APX、CAT以及POD不仅能够较好地指示干旱胁迫对幼苗叶片的生理生化伤害程度,并且可反应叶片开始受胁迫伤害的土壤干旱水平,但是MDA和Pro含量则无法指示;60%FC左右的土壤含水量是白刺花2a生幼苗叶片生理生化代谢受到伤害的干旱强度的阈值.It is a precondition to understand the relationship between plant＇s metabolites and antioxidant enzyme activities and the intensity of drought stress for assessing the their adaptation. A greenhouse experiment was conducted to study the changes of malondialdehyde （MDA）, proline （Pro）, soluble protein, photosynthetic pigment contents, and the activity of superoxide dismutase （SOD）, ascorbate peroxidase （APX）, catalase （CAT） and peroxidase （POD） in the leaves of 2-years-old Sophora davidii seedlings, which grown under different drought intensities （80%, 60%, 40% and 20% FC） for two years. It was found that the MDA and Pro content were increased linearly under drought stress; the parabola curves in protein, Chla, Chlb and carotenoid contents were observed with increasing drought stress and the highest values were obtained under moderate stresses （60% and 40% FC）.The activities of four investigated antioxidant enzymes displayed different response patterns to drought stress. Specifically, the activity of SOD and APX increased under the moderate drought while decreased under the severe stress, however pattern of the CAT activity was opposite with drought stress. The POD activity was showed the lowest under 60% FC, highest under 20% FC. It was suggested that the content of soluble protein and photosynthetic pigments, and the activities of SOD, APX, CAT and POD were sensitive indicators that could effectively reflect the response patterns of the physiological and biochemical activities ofSophora davidii seedlings under drought condition, but the content of MDA and proline were not. For the 2-years-old Sophora davidii seedlings, the 60% FC soil water condition was the threshold at which the negative effect of drought on the physiological and biochemical activities of the leaves begain. Fig 3, Ref 26

关 键 词：白刺花 干旱胁迫 抗氧化酶 生化伤害 田间持水量 FC 

分 类 号：Q945.78[生物学—植物学]