摘要
以郑州9023为供试材料,采用室内水培方法,研究了不同浓度Zn2(+0、30、60、120、240、360mg·L-1)对小麦幼苗生理活性的影响,初步阐明了Zn2+对小麦幼苗的毒害机理。结果表明,在Zn2+胁迫下,随处理浓度的升高,小麦幼苗叶片中超氧阴离子自由基(O·2-)含量、丙二醛(MDA)含量、可溶性糖含量、抗坏血酸过氧化物酶(APX)及过氧化物酶(POD)活性均呈上升趋势,超氧化物歧化酶(SOD)活性呈先下降后上升的趋势;抗坏血酸(ASA)含量、过氧化氢酶(CAT)活性均呈现先上升后下降的趋势,可溶性蛋白和叶绿素含量呈下降趋势。对SOD、POD、CAT同工酶的聚丙烯酰胺凝胶电泳结果分析表明,正常情况下,小麦幼苗叶片主要表达Rf值(相对迁移率)分别为0.98、0.96、0.9、0.8、0.6、0.48的6条SOD同工酶带;POD同工酶带主要分为5区,至少包括10条同工酶酶带;CAT主要表达2条同工酶带。浓度小于120mg·L-1的Zn2+抑制SOD同工酶的表达,促进CAT同工酶的表达,浓度大于240mg·L-1的Zn2+促进SOD同工酶的表达,抑制CAT同工酶的表达,Zn2+诱导小麦幼苗中POD同工酶的表达。Zn2+没有诱导新的CAT、SOD和POD同工酶的表达。
Effects of different concentrations of Zn^2＋（0, 30, 60, 120, 240, 360 mg -L-1） on the physiological activity in wheat seedling of Zhengzhou-9023 were investigated in order to elucidate the toxicity of zinc in the early developmental stage. Different physiological index had different responses to zinc. With increasing concentrations of Zn^2＋, the content of O2^-, MDA and soluble sugar, APX and POD activity all increased gradually. The average O2^- and MDA content at any other concentrations had significant difference compared to that of controls. No significant difference in soluble sugar content was found between under low concentrations of Zn^2＋（0-60 mg·L^-1） and that of controls. APX activity at Zn^2＋ 360mg·L^-1 showed a significant difference compared with that of controls. POD activity was correlated with the concentrations of Zn^2＋（r2--0.942）, but no significant difference was observed among different concentrations. SOD activity decreased when the concentrations of Zn^2＋ was lower than 120 mg·L^-1, and then increased, and at 360 mg·L^-1, no significant difference existed compared to that of controls. ASA content decreased when the concentration was lower than 120mg·L^-1, and then increased. But ASA content was not correlated with the concentrations of Zn^2＋. CAT activity increased with the increase of Zn^2＋, but decreased when the concentration was higher than 60 mg·L^-1. CAT activity at 360mg·L^-1 Zn^2＋ had significant difference compared with that of controls. Content of soluble protein and chlorophyll decreased with increasing concentrations of Zn^2＋, and compared to that of controls, soluble protein significantly decreased at 360 mg·L^-1Zn^2＋. Content of chlorophyll was correlated with the concentrations of Zn^2＋（r2--0.975）. By polyacrylamide gel electrophoresis （PAGE）, Zn^2＋ induced the expres- sion of POD isoenzymes of wheat seedling. When the concentration of Zn^2＋ was lower than 120 mg·L^-1, Zn^2＋ induced the expression of CAT isoenzymes but inhabited the expression of SOD isoenzymes in wheat seedling. However, when the concentration of Zn^2＋ was more than 240 mg·L^-1, Zn^2＋ inhabited the expression of CAT isoenzymes but induced the expression of SOD isoenzymes in wheat seedling. Zn^2＋ didn＇ t induce the expression of new CAT, SOD and POD isoenzymes.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2007年第1期140-145,共6页
Journal of Agro-Environment Science
基金
河南省教育厅自然科学基金项目(2006210009)
河南师范大学应用科学与技术研究基金资助项目(2004Y02)
