NO和H_2O_2对大豆幼苗铝毒害的缓解效应及其相互作用  

Alleviation of Aluminum Toxicity in Soybean Seedlings by Nitric Oxide and Hydrogen Peroxide and Analysis of Their Interaction

作　　者：宋洪明[1] 邢承华[2] 吴坤[1] 王芳妹[1] 何贞泉[3] 蔡妙珍[3] 

机构地区：[1]浙江师范大学化学与生命科学学院,浙江金华321004 [2]金华职业技术学院农业与生物工程学院,浙江金华321007 [3]浙江师范大学地理与环境科学学院,浙江金华321004

出　　处：《环境科学研究》2014年第9期1061-1066,共6页Research of Environmental Sciences

基　　金：国家自然科学基金项目(31101599);浙江省自然科学基金项目(Y3110561)

摘　　要：NO和H2O2作为信号分子参与植物对非生物胁迫的响应,为了确定NO和H2O2介导的大豆耐铝作用以及二者的交互作用,以浙春3号大豆为材料,分析了铝毒胁迫下根尖内源及外源NO和H2O2对大豆铝毒的缓解效应,并研究了NO和H2O2代谢相关酶的活性变化,其中外源NO由SNP(亚硝基铁氰化钠,Na2[Fe(CN)5NO]·2H2O)提供.结果显示:Al处理显著抑制大豆根生长,促使Al在根尖积累并显著提高大豆根尖内源w(NO)和w(H2O2).在H2O2+Al、SNP+Al和H2O2+SNP+Al处理下,大豆根相对伸长率比单独Al处理下分别升高了64.6%、63.5%和69.5%,根尖w(Al)则分别减少了34.6%、36.8%和32.9%,表明NO和H2O2对铝毒害均具有缓解作用.外源NO能够促使根尖内源H2O2显著积累,降低POD(过氧化物酶)活性,而外源H2O2对内源根尖w(NO)无影响.NO和H2O2在缓解铝毒的信号途径中存在信号互作,NO处于H2O2的上游,其通过POD活性调节内源w(H2O2).Nitric oxide（ NO） and hydrogen peroxide（ H2O2） are key signaling molecules in plants. In recent years,the roles of the two compounds in the tolerance of plants to abiotic stress has received much attention,and increasing evidence indicates that NO and H2O2 play essential roles in aluminum（ Al） tolerance. However,the physiological mechanism by which NO and H2O2 alleviate Al toxicity in soybean and their interactions remain unknown. In the present study,we examined the effect of Al on endogenous NO and H2O2 accumulation,the role of exogenous NO and H2O2 in Al tolerance,and enzyme activity related to NO and H2O2 accumulation in soybean root apices. Root elongation and Al content in root tips were used as indicators to detect the effects of NO and H2O2. Al concentration of50 or 100 μmol/L significantly inhibited root growth,increased Al accumulation in root tips,and promoted endogenous NO production.Treatments with H2O2＋ Al,sodium nitroprusside SNP ＋ Al,or H2O2＋ SNP ＋ Al increased relative root length by 64. 6%,63. 5% and69. 5%,respectively,and decreased Al content in the root tips by 34. 6%,36. 8% and 32. 9%,respectively. This showed that an exogenous NO donor SNP and H2O2 both alleviated Al-induced root growth inhibition and Al accumulation in the root apex. Moreover,exogenous NO increased endogenous H2O2 accumulation and decreased peroxidase activity,whereas exogenous H2O2 had no significant effect on endogenous NO production. Collectively,the results showed that NO and H2O2 exhibited a synergistic effect on alleviating Al toxicity in soybean,and NO acted upstream of H2O2 in the signaling pathway through the increment of peroxidasedependent H2O2 accumulation.

关 键 词：铝毒害 NO H2O2 大豆 

分 类 号：X503.231[环境科学与工程—环境工程] S511[农业科学—作物学]