井冈山杜鹃叶片抗氧化系统对高温胁迫的响应  

Responses of Antioxidant System in Leaves of Rhododendron jinggangshanicum to High Temperature Stress

作　　者：周广[1,2] 孙宝腾[1] 张乐华[2] 熊英杰[1] 王书胜[2] 

机构地区：[1]南昌大学生命科学与食品工程学院,南昌330031 [2]中国科学院江西省庐山植物园,江西庐山332900

出　　处：《西北植物学报》2010年第6期1149-1156,共8页Acta Botanica Boreali-Occidentalia Sinica

基　　金：科技部国际科技合作项目(2007DFA31410);江西省国际科技合作项目(2007BN18700);江西省星火计划项目(2008CX06500);江西省教育厅课题(JXJG-07-1-40)

摘　　要：以井冈山杜鹃(Rhododendron jinggangshanicumTam)4年生实生苗为材料,通过人工气候箱盆栽实验,研究了不同高温处理下其叶片形态及生理生化指标的变化,以阐明高温胁迫下井冈山杜鹃抗氧化系统的防御机理。结果显示:(1)30℃和38℃处理6 d后,叶片过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)及过氧化氢酶(CAT)活性分别比对照极显著(P<0.01)升高44.44%和127.16%、33.12%和129.35%、106.52%和188.64%;超氧化物歧化酶(SOD)活性增幅较小,分别比对照增加3.77%和5.11%。(2)随着胁迫温度的升高,可溶性蛋白质、脯氨酸(Pro)含量均明显上升,而抗坏血酸(AsA)含量却显著降低;除30℃处理与对照之间的可溶性蛋白质含量差异显著(P<0.05)外,其它处理间差异均达到极显著(P<0.01)。(3)随着胁迫温度的升高,叶片过氧化氢(H2O2)、丙二醛(MDA)含量大量积累,各处理间差异达到极显著或显著;而形态上则表现为受害加重,植株出现轻度萎蔫、老叶褐化脱落、新叶坏死等现象。研究表明,井冈山杜鹃受到高温胁迫的氧化伤害可能与AsA含量显著下降和H2O2、MDA含量大幅增加有关,其植物体能诱导增加抗氧化保护酶活性及Pro含量以提高其抗氧化能力,从而减轻高温引发的活性氧毒害。In order to illuminate the responsive mechanism of Rhododendron jinggangshanicum Tam under high temperature stress,four-year-old seedlings of R.jinggangshanicum were planted in artificial climate chamber and the morphological,biophysical and biochemical changes of them were determined under different degree of high temperature.The results showed that：（1） After six-days＇ treatment at 30℃ and 38℃,the activities of peroxidase（POD）,ascorbate peroxidase（APX） and catalase（CAT） in the leaves increased by 44.44% and 127.16%,33.12% and 129.35%,106.52% and 188.64% respectively,and the changes were extremely significant（P0.01）.Whereas the changes of SOD were not larger,with the proportion of 3.77% and 5.11% increase,respectively.（2）With the temperature becoming higher,the contents of soluble protein and proline were increased obviously,whereas the content of ascorbic acid（AsA） was largely reduced.When we compared the content of soluble protein with the control level,all treatments reached extremely significant difference（P0.01） except for the one taking place at 30℃,which showed significant difference（P0.05）.（3）With high-temperature strengthening,the content of hydrogen peroxide（H2O2） and malondialdehyde（MDA） accumulated greatly,with each treatment reaching extremely significant or significant differences.It displayed the phenomenon of plants slightly wilting,old leaves browning off and new leaves necrosis occurring.The results gave conclusions that the oxidative damage which R.jinggangshanicum suffered under the high temperature stress may be related to the obvious increase in the content of H2O2 and MDA,as well as largely reduced content of AsA.However,the plant can improve its antioxidant ability and decrease the oxidative damage caused by the high temperature stress through increasing the activities of antioxidant enzymes and the content of proline.

关 键 词：井冈山杜鹃 高温胁迫 膜脂过氧化 抗氧化系统 

分 类 号：Q945.79[生物学—植物学]