NO_2^-源的NO对镉胁迫下玉米幼苗生理的影响  

Effects of nitric oxide,an indirect reaction production of NO_2^-,on the physiological functions of maize under cadmium stress

作　　者：贾佳[1] 徐一馨 李佳[1] 范文强[1] 胡景江[1] 慕自新[1] 

机构地区：[1]西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100

出　　处：《干旱地区农业研究》2016年第1期159-165,185,共8页Agricultural Research in the Arid Areas

基　　金：黄土高原土壤侵蚀与旱地农业国家重点实验室基金(K318009902-14)

摘　　要：采用亚硝酸钠(Na NO2)在酸性条件下与还原剂还原型谷胱甘肽(GSH)反应生成S-亚硝基谷胱甘肽(GSNO),GSNO能够释放出NO,合成不同浓度的GSNO(0、50、125、250μmol·L^(-1)和350μmol·L^(-1))溶液处理受Cd Cl2胁迫的玉米(Zea mays L.)幼苗,以未用Cd Cl2处理的玉米幼苗作为对照(Control),探究GSNO对玉米幼苗Cd胁迫的缓解作用及其抗氧化机制。结果表明:GSNO处理使Cd胁迫下玉米幼苗的株高、茎粗和叶面积与对照组相比显著增加,其中250μmol·L^(-1)浓度的GSNO处理效果最佳;在350μmol·L^(-1)GSNO处理下玉米幼苗各类光合色素含量在胁迫组均达到最大值,有效缓解了叶片黄化;GSNO处理(最适浓度在125~250μmol·L^(-1)之间)也显著增强了Cd胁迫下玉米幼苗的抗氧化酶活性,如超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)和过氧化物酶(POD)的活性,相应地降低了过氧化氢(H2O2)和超氧阴离子(O_2·)含量的积累;GSNO还可以显著提高玉米幼苗螯合重金属离子的能力,其中250μmol·L^(-1)浓度的GSNO处理效果最佳。Gaseous signaling molecule nitric oxide （NO） is proven in many plants to be able to alleviate cadmium （Cd） stress. Under acidic conditions, glutathione （GSH） can react with sodium nitrite （NaNO2） to generate S-nitrosoglutathione （GSNO）, which can release NO. The present work was to study whether this type of NO could help maize seedlings （Zea mays L. ） to resist Cd stress. Different concentrations of GSNO （50, 125, 250 μmol·L^-1, and 350 μmol·L^-1 ） were applied to maize seedlings that had been subjected to 80 mg· L^- 1 CdCl2 for 7 d. The results showed that GSNO could significantly improve maize seedlings plant height, stem diameter, and leaf area, especially at the 250μmol·L^-1 GSNO concentration; The addition of 350μmol·L^-1 GSNO couldmaintain photosynthetic pigment maximization, effectively alleviate leaf yellowing; The benificial effects of GSNO （optimum concentration was in the range of 150 - 250 μmol·L^-1） on Cd-stressed maize might be related to the enhanced antioxidant enzyme activity, such as superoxide dismutase （SOD）, catalase （CAT）, ascorbate peroxidase （APX） and peroxidase （POD）, and decreased levels of H2O2 and O2·^- ; Furthermore, GSNO greatly enhanced the capacity of maize seedlings to chelate heavy metal ions which optimal GSNO concentration was 250μmol·L^-1.

关 键 词：NO S-亚硝基谷胱甘肽 镉胁迫 玉米 生理 

分 类 号：S513.01[农业科学—作物学]