龙葵属两种植物Cd积累特征及其耐性机制对比研究  

Comparative study on Cd accumulation characteristics and tolerance mechanism in the roots of study on Cd accumulation characteristics and tolerance mechanism in the roots of Solanum alatumMoench and Solanum Nigrum L

作　　者：张芬琴[1,2,3] 赵连慧 张瑞琪 张潇 Zhang Fen-qin;Zhao Lian-hui;Zhang Rui-qi;Zhang Xiao(Institute of Hexi Ecology;Rape-maize Research Center for Stress Resistance in Hexi Corridor;Key Laboratory of Characteristic Resources Utilization in Hexi Corridor of Gansu,Zhangye Gansu 734000)

机构地区：[1]河西学院河西生态研究所 [2]河西走廊油菜-玉米抗逆研究中心 [3]甘肃省河西走廊特色资源利用重点实验室,甘肃张掖734000

出　　处：《河西学院学报》2023年第5期35-44,共10页Journal of Hexi University

基　　金：国家自然科学基金项目(项目编号:31560072);甘肃天祝特色农产品信息化管理及数据库建设项目(项目编号:22JR5RG562)。

摘　　要：目的:对比两种龙葵Cd积累特征及其耐性机制。方法:采用基质培养法,用含100μmol·L^(-1)Cd(CdCl_(2)·2.5H_(2)O)完全营养液培养龙葵属植物红果龙葵(Solanum alatum Moench)和龙葵(Solanum nigrum L.)180d(盛果期),测其叶面积、根和茎叶干物质积累、根、茎和叶、细胞不同部位、细胞壁果胶中的Cd含量以及根中Cd的化学形态和细胞壁果胶含量及其相关酶活性。结果:与无Cd相比,(1)100μmol·L^(-1)Cd使两种龙葵根和茎叶干重显著降低(p<0.05),但其地上部分长势良好;(2)Cd主要积累于两种龙葵根中,其次在叶片中;(3)根中的Cd主要以果胶和蛋白质的结合态存在,且主要积累于细胞壁中,其次积累在细胞可溶性部分;细胞壁上的Cd主要积累于螯合态果胶和碱溶性果胶中;(4)Cd使两种龙葵叶细胞壁中螯合态果胶和碱溶性果胶含量以及果胶甲酯酶(PME)活性显著增加(p<0.05)。结论:两种龙葵对Cd均有较好耐性,推测其耐性机制为:根部吸收的Cd以果胶和蛋白质结合态存在,这种形态的Cd因被细胞壁螯合态果胶和碱溶性果胶结合而积累,由此降低其迁移性和毒性;同时,PME活性增强使果胶去甲酯化加速可为Cd在细胞壁上积累提供更多结合位点。Solanum alatum Moench and Solanum nigrum L.were cultured in a complete nutrient solution containing 100μmol·L^(-1) Cd(CdCl_(2)·2.5H_(2)O)to full fruit stage by substrate culture method.By measuring leaf area,accumulation of dry matter in roots,stems and leaves,accumulation of Cd in roots,stems and leaves,different parts of cells,the pectin of cell wall,chemical form of Cd in leaves,content of different types of pectin in cell wall and related enzyme activities,the tolerance mechanism of two kinds of plant to Cd was studied.The results showed as follows:compared with the control,(1)Cd significantly reduced the dry weight of root,stem and leaf(P<0.05),but the aboveground part grew well.(2)Cd mainly accumulated in the roots of the two kinds of plant,followed by the leaves.(3)Cd in roots existed in the binding state with pectin and protein,which was significantly higher than that in other forms(P<0.05),and Cd mainly accumulated the wall,followed by soluble part of cell in leaves,Cd on cell wall is mainly accumulated in chelated pectin and alkali-soluble pectin.(4)Cd significantly increased the contents of chelated pectin and alkali-soluble pectin and the activity of pectin methyl esterase(PME)in the cell wall of roots of two kinds of plant(P<0.05).It is thus clear that both of had good tolerance to Cd,and one of their tolerance mechanisms was speculated as follows:Cd absorbed by plant roots existed in the binding state with pectin and protein,which mainly bound to the chelated and alkali-soluble pectin in cell wall to reduce its migration and toxicity,and the enhanced PME activity speeded up the demethylation of pectin,which provided more binding sites for Cd accumulation on the cell wall.

关 键 词：红果龙葵 龙葵 Cd积累特征 耐镉 机理研究 

分 类 号：S32[农业科学—作物遗传育种]