Uptake, Subcellular Distribution, and Chemical Forms of Cadmium in Wild-Type and Mutant Rice  

作　　者：HE Jun-Yu ZHU Cheng REN Yan-Fang YAN Yu-Ping CHENG Chang JIANG De-An SUN Zong-Xiu 

机构地区：[1]State Key Laboratory of Plant Physiology ＆ Biochemistry, College of Life Science, Zhejiang University, Hangzhou310058 （China） [2]College＇of Agriculture, Guizhou University, Guizhou 550025 （China） [3]State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006 （China）

出　　处：《Pedosphere》2008年第3期371-377,共7页土壤圈（英文版）

基　　金：the National Natural Science Foundation of China (No30671255);the National Key Technologies R&D Program of China during the 11th Five-Year Plan Period (No2006BAK02A18);the National Basic Research Program (973) of China (No2002CB410804)

摘　　要：Wild-type （Zhonghua 11） and mutant rice （Oryza sativa L.） plants were used to investigate the effect of cadmium （Cd） application on biomass production, to characterize the influx of Cd from roots to shoots, and to determine the form, content, and subcellular distribution of Cd in the roots, leaf sheaths, and leaves of the rice plants. Seedlings were cultivated in a nutrient solution and were treated with 0.5 mmol L^-1 of Cd^2＋ for 14 d. The sensitivity of rice plants to Cd toxicity was tested by studying the changes in biomass production and by observing the onset of toxicity symptoms in the plants. Both the wild-type and mutant rice plants developed symptoms of Cd stress. In addition, Cd application significantly （P ≤ 0.01） decreased dry matter production of roots, leaf sheaths, and leaves of both types, especially the mutant. The Cd content in roots of the mutant was significantly （P ≤0.05） higher than that of the wild-type rice. However, there was no significant difference in the Cd content of roots, leaf sheaths, and leaves between the wild-type and mutant rice. Most of the Cd was bound to the cell wall of the roots, leaf sheaths, and leaves, and the mutant had greater Cd content in cell organelles than the wild type. The uneven subcellular distribution could be responsible for the Cd sensitivity of the mutant rice. Furthermore, different chemical forms of Cd were found to occur in the roots, leaf sheaths, and leaves of both types of rice plants. Ethanol-, water-, and NaCl-extractable Cd had greater toxicity than the other forms of Cd and induced stunted growth and chlorosis in the plants. The high Cd content of the toxic forms of Cd in the cell organelles could seriously damage the cells and the metabolic processes in mutant rice plants.Wild-type(Zhonghua 11) and mutant rice(Oryza sativa L.) plants were used to investigate the effect of cadmium(Cd) application on biomass production,to characterize the inffux of Cd from roots to shoots,and to determine the form,content,and subcellular distribution of Cd in the roots,leaf sheaths,and leaves of the rice plants.Seedlings were cultivated in a nutrient solution and were treated with 0.5 mmol L-1 of Cd2+ for 14 d.The sensitivity of rice plants to Cd toxicity was tested by studying the changes in biomass production and by observing the onset of toxicity symptoms in the plants.Both the wild-type and mutant rice plants developed symptoms of Cd stress.In addition,Cd application significantly(P ≤ 0.01) decreased dry matter production of roots,leaf sheaths,and leaves of both types,especially the mutant.The Cd content in roots of the mutant was significantly(P ≤ 0.05) higher than that of the wild-type rice.However,there was no significant di?erence in the Cd content of roots,leaf sheaths,and leaves between the wild-type and mutant rice.Most of the Cd was bound to the cell wall of the roots,leaf sheaths,and leaves,and the mutant had greater Cd content in cell organelles than the wild type.The uneven subcellular distribution could be responsible for the Cd sensitivity of the mutant rice.Furthermore,different chemical forms of Cd were found to occur in the roots,leaf sheaths,and leaves of both types of rice plants.Ethanol-,water-,and NaCl-extractable Cd had greater toxicity than the other forms of Cd and induced stunted growth and chlorosis in the plants.The high Cd content of the toxic forms of Cd in the cell organelles could seriously damage the cells and the metabolic processes in mutant rice plants.

关 键 词：CADMIUM chemical form RICE subcellular distribution UPTAKE 

分 类 号：S511[农业科学—作物学]