Endogenous nitric oxide mediates alleviation of cadmium toxicity induced by calcium in rice seedlings

作     者：Long Zhang Zhen Chen Cheng Zhu 

作者机构：State Key Laboratory of Plant Physiology and BiochemistryCollege of Life SciencesZhejiang UniversityHangzhou 310058China College of Life SciencesChina Jiliang UniversityHangzhou 310018China School of Life SciencesTaizhou UniversityTaizhou 317000China 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2012年第24卷第5期

页      面：940-948页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 09[农学] 0901[农学-作物学] 0703[理学-化学] 070301[理学-无机化学] 

基　　金：supported by the Zhejiang Provincial Natural Science Foundation of China (No. Y3100246) the Innovation Team of the Safety Standards and Testing Technology for Agricultural Products of Zhejiang Province(No. 2010R50028) 

主　　题：nitric oxide cadmium calcium nonprotein thiols protein thiols matrix polysaccharides 

摘      要：The effect of calcium chloride （CaCl2） on rice seedling growth under cadmium chloride （CdCl2） stress, as well as the possible role of endogenous nitric oxide （NO） in this process, was studied. The growth of rice seedlings was seriously inhibited by CdCl2, and the inhibition was significantly mitigated by CaCl2. However, hemoglobin （Hb） and 2-（4-carboxyphenyl）-4, 4,5,5-tetramethylimidazoline- l-oxyl-3-oxide （cPTIO） weakened the promotion effect of CaCl2. The results of NO fluorescence localization suggest that growth accelerated by CaCl2 might be associated with elevated NO levels. The content of Cd, protein thiols （PBT）, and nonprotein thiols （NPT） in cell walls, cell organelles, and soluble fractions, respectively, of rice seedlings decreased considerably in the presence of CaCl2, whereas the content of pectin, hemicellulose 1 （HC1）, and hemicellulose 2 （HC2） increased significantly. Elimination of endogenous NO in Cd＋Ca treatment could promote the transportation of Cd2＋ to cell organelles and soluble fractions and increase the content of NPT and PBT in leaves. In addition, transportation of Cd2＋ to cell organelles and soluble fractions was retarded in roots, the content of NPT increased, and the content of PBT decreased. With elimination of endogenous NO in Cd＋Ca treatment, the content of pectin, HC1, and HC2 decreased significantly. Thus, Ca may alleviate Cd toxicity via endogenous NO with variation in the levels of NPT, PBT, and matrix polysaccharides.