叶面喷施2,3-二巯基丁二酸降低水稻幼苗茎叶镉含量的机制  

Mechanism of foliar spraying of 2,3-dimercaptosuccinic acid(DMSA)affects cadmium content in shoots of rice seedlings

作　　者：王晓丽 王常荣 刘仲齐 黄益宗 孔维勇 黄永春 刘斌[2] WANG Xiaoli;WANG Changrong;LIU Zhongqi;HUANG Yizong;KONG Weiyong;HUANG Yongchun;LIU Bin(Agro-Environmental Protection Institute,Ministry of Agriculture and Rural Affairs,Tianjin 300191,China;Agricultural Resource and Environment Research Institute,Guangxi Academy of Agricultural Sciences,Nanning 537000,China)

机构地区：[1]农业农村部环境保护科研监测所,天津300191 [2]广西农业科学院农业资源与环境研究所,南宁537000

出　　处：《农业环境科学学报》2023年第5期974-983,共10页Journal of Agro-Environment Science

基　　金：国家自然科学基金项目(42077153);农业农村部环境保护科研监测所基本科研业务费(2021-HYC-11)。

摘　　要：为探寻叶面喷施2,3-二巯基丁二酸(DMSA)降低水稻幼苗茎叶镉含量的潜在机制,在人工气候室内,采用水培实验方法研究了镉在幼苗不同部位的累积情况及喷施DMSA对镉胁迫的影响。结果表明:随着DMSA喷施浓度增加,茎基镉含量呈显著增加趋势,当DMSA喷施浓度达到1.0 mmol·L^(-1)时茎基镉含量与对照(不喷施DMSA)处理相比显著增加57.3%,同时镉由茎基向地上部的转移效率降低52.7%。在此基础上,探寻了镉在茎基细胞中的赋存形态及镉的亚细胞分布情况,结果表明茎基中难溶态镉含量与对照处理相比显著增加了80.8%,细胞壁中镉含量达到对照处理的2.1倍。进一步对细胞壁各组分镉含量进行测定发现,果胶组分中镉含量随着DMSA喷施浓度增加呈现出显著升高趋势,与对照处理相比最高增加99.5%。此外,喷施DMSA后茎基中总植物螯合素(PCs)和谷胱甘肽(GSH)含量均呈现出显著增加趋势,最高分别达到对照处理组的2.2倍和3.1倍。喷施DMSA显著缓解了镉胁迫,幼苗地上部超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性分别升至对照处理的3.0倍和2.7倍,荧光标记试验表明叶片中过氧化氢含量随DMSA喷施浓度增加呈现显著降低趋势。研究表明,喷施DMSA显著增加了水稻幼苗茎基巯基化合物含量,从而提高了对镉的拦截能力,降低了镉由茎基向幼苗地上部转运效率,使水稻幼苗地上部镉含量显著降低,同时喷施DMSA还可显著缓解幼苗镉胁迫。In order to explore the potential mechanism of foliar spraying of 2,3-dimercaptosuccinic acid(DMSA)to reduce the cadmium(Cd)content in the stems and leaves of rice seedlings,the accumulation of Cd in different organs of the seedlings and the effects on Cd stress were studied in an artificial climate chamber by using a hydroponic experiment.The results showed that with the increase of DMSA spraying concentration,the Cd content of the shoot base significantly increased.When the DMSA spraying concentration reached 1.0 mmol·L^(-1),the Cd content of the shoot base significantly increased by 57.3%compared with the control treatment,and the transfer factor of Cd from the shoot base to the shoot decreased by 52.7%.It was found that when the concentration of DMSA reached 1.0 mmol·L^(-1),insoluble Cd content increased significantly by 80.8%compared with the control treatment.The subcellular distribution test showed that the Cd content of the cell wall increased significantly with the DMSA spraying concentration.When the spraying concentration reached 1.0 mmol·L^(-1),the Cd content of the cell wall was about 2.1 times that of the control group.Further analysis of the Cd content of cell wall components showed that the Cd content in pectin increased with DMSA spraying concentration,and the highest increase was 99.5%when compared with the control treatment.In addition,after spraying DMSA,total phytochelatin and glutathione content of the stem base showed significant increasing trends,and the highest measured values were 2.2 times and 3.1 times those of the control group,respectively.After spraying DMSA,the activities of SOD and CAT in shoots increased to 3.0 times and 2.7 times,respectively.A fluorescence labeling test showed that the content of hydrogen peroxide in leaves also decreased significantly.The above results showed that the spraying of DMSA significantly increased the content of sulfhydryl compounds in the stem base of rice seedlings,improved the ability to intercept cadmium,reduced the efficiency of Cd transport

关 键 词：水稻 镉 2 3-二巯基丁二酸 茎基 细胞壁 

分 类 号：X173[环境科学与工程—环境科学] X53[农业科学—作物学] S511