镉胁迫对镉低积累突变体cadL-5非酶促防御系统的影响  

Effects of Non-enzymatic Defense System on Cadmium Low Accumulation Rice Mutant cad L- 5 Under Cd Stress

作　　者：沈国明[1,2] 上官李娜[2] 

机构地区：[1]菏泽学院生命科学系/植物生物学重点实验室,山东菏泽274015 [2]浙江大学生命科学学院,浙江杭州310058

出　　处：《核农学报》2016年第6期1186-1195,共10页Journal of Nuclear Agricultural Sciences

基　　金：山东省高等学校青年骨干教师国内访问学者项目;菏泽学院博士基金(XY13BS01);菏泽学院植物生物学重点实验室建设项目

摘　　要：为探讨水稻镉(Cd)低积累的生理生化机制,以从500份农杆菌介导的水稻T-DNA/Ds插入突变体库中筛选到的镉低积累突变体cad L-5和其野生型水稻粳稻中花11为材料,经Cd Cl2处理后,通过常规生物化学方法,对其脯氨酸和H2O2含量、As A/DHA、GSH/GSSG及NADPH/NADP+比值和相应酶活性进行测定。结果表明,随着处理浓度的提高,低镉积累突变体cad L-5植株器官中Cd和H2O2积累量低于野生型,而游离脯氨酸含量则相反;GSH/GSSG、As A/DHA及NADPH/NADP+的比值均表现为cad L-5高于野生型;抗坏血酸氧化酶还原型谷胱甘肽酶,脱氢抗坏血酸还原酶和单脱氢抗坏血酸还原酶活性也均表现为cad L-5高于野生型。植物对Cd的抗性或低积累依赖于植物的抗氧化保护系统,在这个抗氧化保护系统中抗坏血酸-谷胱甘肽(As A-GSH)循环起着至关重要的作用。本研究结果为从分子水平把握植物对Cd的抗性研究积累了生理学方面的资料。To investigate the physiological and biochemical mechanisms of ricelow accumulation of cadmium（Cd） in rice, a low Cd accumulation mutant cadL-5 obtained from 500 strains of the Agrobacterium mediated rice T-DNA/Ds insertion mutant pool and wild type Zhonghua 11 as materials were used in this study. The mutant and WT plants were treated with different concentrations of CdCl2 for 10 d and sampling. The contents of proline and H2O2, and the ratios of AsA/DHA, GSH/GSSG and NADPH/NADP^＋ and the corresponding enzyme activities were determined. Along with the increase of the external concentrations of Cd, results showed that the accumulation of Cd and hydrogen peroxide （H2O2） in cadL-5 was lower in the WT, while free proline content on the contrary; The ratios of reduced glutathione and oxidized glutathione, ascorbic acid and dehydrogenation ascorbic acid and reduced nicotinamide adenine dinucleotide phosphate and nicotinamide adenine dinucleotide phosphate in cadL-5 were higher than those in the WT. The activities of ascorbate oxidase, glutathione reductase, dehydroascorbate reductase and monodehydroascorbate reductase in cadL-5 were higher than in the WT. Based on the results, it can be proposed that the resistance of plants to Cd may depend on the oxidation protection system, in which ascorbate-glutathione （AsA-GSH） cycle plays a vital role. The results also shed lights on the future investigation to understand plant resistance to cadmium at the molecular level and provide some information of physiological and biochemical data.

关 键 词：抗坏血酸-谷胱甘循环 镉低积累突变体 过氧化氢 水稻 

分 类 号：Q945.78[生物学—植物学]