铁或铜胁迫下小麦幼苗根抗氧化体系的响应  

Antioxidative response in wheat seedlings under iron or copper stress

作　　者：杨颖丽[1] 丁凡[1] 段晓晖[1] 滕玉瑾 马婷[1] 李翠祥[1] 张丽[1] 

机构地区：[1]西北师范大学生命科学学院,兰州730070

出　　处：《兰州大学学报（自然科学版）》2015年第2期248-254,共7页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金项目(31360094;31470464)

摘　　要：为揭示小麦幼苗在Fe或Cu胁迫下的抗氧化反应机制,以宁春4号小麦为材料,比较了不同浓度(0,100,300,500μmol/L)Fe Cl3或Cu Cl2处理下幼苗根羟自由基(·OH)含量、抗氧化酶活性和多胺降解酶活性的变化.结果显示:Fe或Cu处理诱导小麦根·OH含量升高,且高浓度Cu处理下样品·OH含量高于相同浓度Fe处理的样品的.Fe或Cu处理对各种抗氧化酶活性有不同的影响:Fe诱导超氧化物歧化酶活性升高,而Cu抑制该酶活性;Fe处理不影响过氧化物酶活性,而Cu诱导该酶活性升高;过氧化氢酶活性在Fe或Cu处理下均受到明显的抑制;Fe或Cu处理抑制谷胱甘肽还原酶活性;300,500μmol/L的Fe和100,300μmol/L的Cu诱导抗坏血酸过氧化物酶活性的升高.此外,不同浓度的Fe或Cu对多胺氧化酶(PAO)、二胺氧化酶(DAO)和细胞壁过氧化物酶(cw-POD)活性均有明显的抑制作用.结果表明:Fe或Cu胁迫诱导对小麦根不同抗氧化酶产生不同的影响,最终导致小麦根·OH积累;PAO,DAO和cw-POD可能不参与Fe或Cu胁迫诱导的ROS积累.The changes of hydroxyl radicals （. OH） content, antioxidant enzyme activities and polyamines degradation enzyme activities were compared in order to elucidate the antioxidative response mechanism when wheat roots were exposed to 0, 100, 300, 500 #mol/L Fe or Cu. Fe- and Cu-treated roots exhibited significant elevation in · OH content, with the highest content due to 500μmol/L Cu stress. These two metals had different effects on antioxidant enzymes. Fe stress stimulated the activities of superoxide dismutase （SOD） and ascorbate peroxidase （APX） but inhibited the activities of catalase （CAT） and glutathione reductase （GR）, while decreased SOD, CAT and GR activities but increased peroxidases （POD） and APX activities were found in Cu-stressed roots. In addition, different Fe or Cu concentrations caused notable inhibition of polyamine oxidase （PAO）, diamine oxidase （DAO） and cell wall-bound peroxidase （cw-POD） activities in the roots. Taken together, the results suggested that Fe or Cu stress caused ·OH accumulation in wheat roots, and antioxidant enzymes activities showed different changes in response to these two metals. It was also indicated that PAO, DAO and cw-POD might not be associated with reactive oxygen species accumulation in wheat roots under Fe or Cu treatment.

关 键 词：小麦 铁 铜 抗氧化反应 

分 类 号：Q945[生物学—植物学]