Cd胁迫下水稻Cd亚细胞特征及游离氨基酸含量变化分析

Analysis of Cd Subcellular Characteristics and the Changes ofFree Amino Acid Contents in Rice Under Cd Stress

以Nipponbare和Lemont水稻为材料,通过水培营养液中添加不同Cd浓度处理,探讨Cd胁迫对不同水稻色素含量、Cd亚细胞分布及游离氨基酸含量的影响。结果表明:随Cd浓度升高,2种水稻呈现叶绿素和类胡萝卜素下降,细胞壁、细胞质和细胞器Cd含量明显增加的趋势;Nipponbare和Lemont水稻在不同处理下细胞壁Cd含量占细胞总Cd含量比例分别为86.24%~88.59%和88.66%~94.17%,表明细胞壁是水稻积累Cd的主要部位;在Cd 50μmol·L^(-1)及Cd 100μmol·L^(-1)处理时,两种水稻脯氨酸、半胱氨酸及谷氨酸含量随Cd处理浓度增加而显著增加,Cd 50μmol·L^(-1)处理浓度显著提高两种水稻丙氨酸、苯丙氨酸、甲硫氨酸和甘氨酸含量,但Cd 100μmol·L^(-1)处理浓度时,Nipponbare水稻苯丙氨酸、甲硫氨酸以及Lemont水稻丙氨酸、甲硫氨酸和甘氨酸未显著增加。总之,Cd胁迫下,2种水稻通过调整Cd亚细胞分布以及积累游离氨基酸含量等方式增强Cd抗性,而且呈现出Nipponbare与Lemont品种间基因型差异。

By taking the rice varieties of Nipponbare and Lemont as the materials,the effects of Cd stress on the content of pigment,the subcellular distribution of Cd and the content of free amino acid in different rice varieties were explored by being treated with adding different concentrations of Cd in the hydroponic nutrient solution.The results showed that with the increase of Cd concentration,the two kinds of rice showed a decreasing trend of the contents of chlorophyll and carotenoid,while the content of Cd in cell wall,cytoplasm and organelle increased significantly.The Cd content in cell wall of the rice varieties of Nipponbare and Lemont under different treatments accounted for 86.24%-88.59%and 88.66%-94.17%of the total contents of Cd in cells,respectively,indicating that the cell wall was the main part of Cd accumulation in rice.When treated with Cd of 50μmol·L^(-1) and Cd of 100μmol·L^(-1),the contents of proline,cysteine and glutamic acid in the two rice varieties of Nipponbare and Lemont increased significantly with the increase of Cd concentration.Under the treatment of 50μmol·L^(-1) Cd,the contents of alanine,phenylalanine,methionine and glycine in the two rice varieties could be increased significantly.However,under the treatment of 100μmol·L^(-1) Cd,However,the contents of phenylalanine and methionine in Nipponbare rice and alanine,methionine and glycine in Lemont rice were not significantly increased.In summary,under the stress of Cd,the two rice varieties enhanced the resistance of Cd by adjusting the subcellular distribution of Cd and accumulating the content of free amino acids,and showed the genotypic differences between Nipponbare and Lemont varieties.