Optimized silicon fertilization regime weakens cadmium translocation and increases its biotransformation in rice tissues  

作　　者：Bogui Pan Yixia Cai Kunzheng Cai Jihui Tian Wei Wang 

机构地区：[1]College of Natural Resources and Environment,South China Agricultural University,Guangzhou 510642,Guangdong,China [2]Guangdong Provincial Key Laboratory of Eco-Circular Agriculture,Guangzhou 510642,Guangdong,China [3]Key Laboratory of Tropical Agricultural Environment in South China,Ministry of Agriculture and Rural Affairs,Guangzhou 510642,Guangdong,China [4]College of Agriculture,South China Agricultural University,Guangzhou 510642,Guangdong,China

出　　处：《The Crop Journal》2024年第4期1041-1053,共13页作物学报（英文版）

基　　金：supported by the Science and Technology Planning Program of Guangdong Province(2013B020310010 and 2019B030301007);the Open Foundation of Key Laboratory for Agricultural Environment,Ministry of Agriculture and Rural Affairs,P.R.China.

摘　　要：In acidic paddy fields of South China,rice(Oryza sativa L.)faces the dual challenges of cadmium(Cd)toxicity and silicon(Si)deficiency.Although previous studies have highlighted the functions of Si application timing and strategies in mitigating Cd-stressed rice,the precise mechanisms underlying the health restoration of Cd-toxic rice and the assurance of grain safety remain elusive.This study explored Cd translocation and detoxification in the shoots of rice regulated by various Si fertilization regimes:Si(T)(all Si added before transplanting),Si(J)(all Si added at jointing),and Si(TJ)(half Si added both before transplanting and at jointing).The findings revealed that the regime of Si(TJ)was more beneficial to rice health and grain safety than Si(T)and Si(J).The osmotic regulators such as proline,soluble sugars,and soluble proteins were significantly boosted by Si(TJ)compared to other Si treatments,and which enhanced membrane integrity,balanced intracellular pH,and increased Cd tolerance of rice.Furthermore,Si(TJ)was more effective than Si(T)and Si(J)on the Cd sequestration in the cell wall,Cd bio-passivation,and the down-regulated expression of the Cd transport genes.The concentrations of Cd in the xylem and phloem treated with Si(TJ)were reduced significantly.Additionally,Si(TJ)facilitated much more Cd bound with the outer layer proteins of grains,and promoted Cd chelation and complexation by phytic acid,phenolics,and flavonoids.Overall,Si(TJ)outperformed Si(T)and Si(J)in harmonizing the phycological processes,inhibiting Cd translocation,and enhancing Cd detoxification in rice plant.Thereby the split Si application strategy offers potential for reducing Cd toxicity in rice grain.

关 键 词：CADMIUM Silicon Growth stages Translocation and accumulation RICE Safe production 

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