In some densely-populated countries, farmland has been widely cadmium (Cd) contaminated, and the utilization of the contaminated farmland for crop production is currently unavoidable. This necessitates the use of low-...In some densely-populated countries, farmland has been widely cadmium (Cd) contaminated, and the utilization of the contaminated farmland for crop production is currently unavoidable. This necessitates the use of low-Cd crops (i.e., pollution-safe cultivars, the crop varieties with the ability to accumulate a low level of Cd in their edible parts when grown on polluted soil) in these areas and highlights the importance of knowledge on phenotypic variation in crop Cd accumulation for food Cd risk control. Studies on phenotypic variation in heavy metal accumulation started decades ago for a wide range of crops, and synthesis of the scattered experimental results in the literature is in need. We built a Low-Cd Crops Database based on literature research, and relevant meta-analysis was performed to quantitatively explore the phenotypic variation in Cd uptake and translocation of rice and wheat. Considerable variability existed among rice (median grain Cd bioconce nt ration factor (BCF) of 0.10) and wheat (median grain Cd BCF of 0.21) phenotypes in grain Cd accumulation, and this variability was labile to soil pH and the level of Cd stress. Wheat statistically had a higher root-to-shoot Cd-translocating ability than rice, highlighting potential food Cd risks and the importance of growing low-Cd wheat in slightly Cd-contaminated regions. Meanwhile, no correlations were detected among soil-to-root, root-to-shoot, and shoot-to-grain translocation factors, implying that Cd uptake and internal translocation in crops were probably controlled by different underlying gene tic mechanisms. Root-to-shoot Cd transport could be a favorable target trait for selecting and breeding low-Cd rice and wheat. In all, this review provides a comprehensive low-Cd crop list for remediation practice and a systematic meta-analysis inferring food Cd risks based on plant capacity for Cd accumulation and desired traits for low-Cd crop breeding.展开更多
Cadmium(Cd)contamination in paddy soils means that the rice produced there may be unsafe for human consumption.A hydroponic study was conducted to enrich rice seedlings with zinc(Zn)or manganese(Mn),and the uptake and...Cadmium(Cd)contamination in paddy soils means that the rice produced there may be unsafe for human consumption.A hydroponic study was conducted to enrich rice seedlings with zinc(Zn)or manganese(Mn),and the uptake and transport characteristics of Cd in these Zn-and Mn-rich seedlings were subsequently investigated using a greenhouse pot trial.The results showed that hydroponic cultivation in 10-50μmol L^(-1) Zn(ZnSO_(4)·7 H_(2)O)or50-250μmol L^(-1) Mn(MnSO_(4)·H_(2)O)for 30 d had no significant impact on rice growth,while the accumulation of Zn and Mn was 7.31-18.5 and 25.4-47.7 times higher,respectively,than in the control(no Zn or Mn addition).The accumulation of Cd in the Zn-and Mn-rich rice plants was 26.3%-38.6% and 34.4%-44.5% lower than that in the control,respectively,and the translocation factors of Cd from roots to shoots also decreased by 23.3%-41.3% and 25.3%-37.0%,respectively,after transplanting to Cd-contaminated soils.Furthermore,the relative expression levels of OsIRT1(Oryza sativa iron-regulated transporter 1)were downregulated by 40.1%-59.3% and 16.0%-25.9%,respectively,in the Zn-and Mn-rich seedling roots.This downregulation may indicate a possible mechanism contributing to the reductions in Cd absorption.Field experiments confirmed that the Zn-and Mn-rich seedlings produced brown rice(unpolished rice grains)with significantly decreased concentrations of Cd(34.2%-44.4%).This study provides an innovative method for reducing the food safety risks from rice grown on slightly to moderately Cd-contaminated paddy soils.展开更多
Cadmium(Cd)pollution affects plant growth and poses a serious threat to food safety and human health.Cadmium-contaminated rice is assumed to be the main source of Cd exposure to humans,with grave health risks.Phytorem...Cadmium(Cd)pollution affects plant growth and poses a serious threat to food safety and human health.Cadmium-contaminated rice is assumed to be the main source of Cd exposure to humans,with grave health risks.Phytoremediation is an efficient,cost-effective,and eco-friendly approach to minimize Cd accumulation in rice.However,research on the effect of rice intercropping with wetland plants that exhibit great capacity for phytoremediation in decreasing Cd concentrations in paddies is limited.A pot experiment in greenhouse was conducted to evaluate the effect of rice intercropping with two wetland plants(Pontederia cordata and Canna indica)under different soil Cd levels(0,1,10,and 25 mg kg^(-1))on rice growth and Cd accumulation and translocation.The results showed that rice intercropping with the two wetland plants significantly improved plant height,tiller,and biomass of rice,but reduced Cd bioconcentration factors(BCFs)and Cd concentrations in rice and wetland plants.Compared with rice monocropping,the BCF in rice grain under 25 mg kg^(-1)soil Cd level significantly decreased by 54.39%and 59.65%in the systems of rice intercropping with C.indica and P.cordata,respectively.In addition,intercropping inhibited the increase in BCFs in rice and wetland plants under increasing soil Cd levels.In conclusion,the systems of rice intercropping with P.cordata and C.indica can be considered two new and effective approaches for ameliorating Cd pollution in paddies,as well as minimizing Cd accumulation in rice and improving food safety.Of the two intercropping systems,rice intercropping with P.cordata performed better than intercropping with C.indica.展开更多
This paper studied the relationship between heavy metal concentrations of herbaceous plants and soils at four Pb-Zn mining sites in Yunnan,China.50 herbaceous plant samples of 9 plant species from 4 families and 50 so...This paper studied the relationship between heavy metal concentrations of herbaceous plants and soils at four Pb-Zn mining sites in Yunnan,China.50 herbaceous plant samples of 9 plant species from 4 families and 50 soil samples were collected and then ana1yzed for the tota1 concentrations of Pb,Cd,and Zn.The results showed that the average concentrations of Pb,Cd,and Zn in soil samples were 3772.83,168.81,and 5385.65 mg/kg,respectively.The average concentrations of Pb,Cd,and Zn were 395.68,28.14,and 1664.20 mg/kg in the shoots,and 924.12,57.25,and 1778.75 mg/kg in the roots,respectively.Heterospecific plants at the same site and conspecific plants at various sites had different average levels of Pb,Cd,and Zn,both in the shoots and the roots.Enrichment coefficients of Pb,Cd,and Zn were greater than 1 in 2,3,and 9 herbaceous plant samples,respectively.Translocation factors of Pb,Cd,and Zn were greater than 1 in 10,17,and 25 herbaceous plant samples,respectively.In all 50 samples,the concentrations of Pb,Cd,and Zn between the shoots and the roots,the shoots,and the soils,and the roots and the soils had significant positive relationships.展开更多
基金?nancially supported by the National Key Research and Development Program of China (No.2018YFD0800306)the Hebei Science Fund for Distinguished Young Scholars,China (No.D2018503005)
文摘In some densely-populated countries, farmland has been widely cadmium (Cd) contaminated, and the utilization of the contaminated farmland for crop production is currently unavoidable. This necessitates the use of low-Cd crops (i.e., pollution-safe cultivars, the crop varieties with the ability to accumulate a low level of Cd in their edible parts when grown on polluted soil) in these areas and highlights the importance of knowledge on phenotypic variation in crop Cd accumulation for food Cd risk control. Studies on phenotypic variation in heavy metal accumulation started decades ago for a wide range of crops, and synthesis of the scattered experimental results in the literature is in need. We built a Low-Cd Crops Database based on literature research, and relevant meta-analysis was performed to quantitatively explore the phenotypic variation in Cd uptake and translocation of rice and wheat. Considerable variability existed among rice (median grain Cd bioconce nt ration factor (BCF) of 0.10) and wheat (median grain Cd BCF of 0.21) phenotypes in grain Cd accumulation, and this variability was labile to soil pH and the level of Cd stress. Wheat statistically had a higher root-to-shoot Cd-translocating ability than rice, highlighting potential food Cd risks and the importance of growing low-Cd wheat in slightly Cd-contaminated regions. Meanwhile, no correlations were detected among soil-to-root, root-to-shoot, and shoot-to-grain translocation factors, implying that Cd uptake and internal translocation in crops were probably controlled by different underlying gene tic mechanisms. Root-to-shoot Cd transport could be a favorable target trait for selecting and breeding low-Cd rice and wheat. In all, this review provides a comprehensive low-Cd crop list for remediation practice and a systematic meta-analysis inferring food Cd risks based on plant capacity for Cd accumulation and desired traits for low-Cd crop breeding.
基金jointly sponsored by the National Key Technology Research and Development Program of China(No.2015BAD05B04)the Natural Science Foundation of Jiangxi Province,China(No.20202BAB215016)+3 种基金the Foundation of Jiangxi Educational Committee,China(No.GJJ191707)the Science and Technology Service Network Program of Chinese Academy of Sciences(STS Program)the Regional Soil Pollution Control Program of the Ministry of Agriculture and Rural Affairs of Chinathe Agro-Environmental Protection Program of Jiangxi Province,China。
文摘Cadmium(Cd)contamination in paddy soils means that the rice produced there may be unsafe for human consumption.A hydroponic study was conducted to enrich rice seedlings with zinc(Zn)or manganese(Mn),and the uptake and transport characteristics of Cd in these Zn-and Mn-rich seedlings were subsequently investigated using a greenhouse pot trial.The results showed that hydroponic cultivation in 10-50μmol L^(-1) Zn(ZnSO_(4)·7 H_(2)O)or50-250μmol L^(-1) Mn(MnSO_(4)·H_(2)O)for 30 d had no significant impact on rice growth,while the accumulation of Zn and Mn was 7.31-18.5 and 25.4-47.7 times higher,respectively,than in the control(no Zn or Mn addition).The accumulation of Cd in the Zn-and Mn-rich rice plants was 26.3%-38.6% and 34.4%-44.5% lower than that in the control,respectively,and the translocation factors of Cd from roots to shoots also decreased by 23.3%-41.3% and 25.3%-37.0%,respectively,after transplanting to Cd-contaminated soils.Furthermore,the relative expression levels of OsIRT1(Oryza sativa iron-regulated transporter 1)were downregulated by 40.1%-59.3% and 16.0%-25.9%,respectively,in the Zn-and Mn-rich seedling roots.This downregulation may indicate a possible mechanism contributing to the reductions in Cd absorption.Field experiments confirmed that the Zn-and Mn-rich seedlings produced brown rice(unpolished rice grains)with significantly decreased concentrations of Cd(34.2%-44.4%).This study provides an innovative method for reducing the food safety risks from rice grown on slightly to moderately Cd-contaminated paddy soils.
基金supported by the Science and Technology Planning Program of Guangdong Province,China(Nos.2021B0202030002,2016A020210094,and 2019B030301007)the National Natural Science Foundation of China(No.32001190)+1 种基金the Innovation Team Construction Project of Modern Agricultural Industry Technology System of Guangdong Province,China(Nos.2018LM1100,2019KJ105,and 2020KJ105)the Science and Technology Project of Guangzhou,China(No.201604020062)。
文摘Cadmium(Cd)pollution affects plant growth and poses a serious threat to food safety and human health.Cadmium-contaminated rice is assumed to be the main source of Cd exposure to humans,with grave health risks.Phytoremediation is an efficient,cost-effective,and eco-friendly approach to minimize Cd accumulation in rice.However,research on the effect of rice intercropping with wetland plants that exhibit great capacity for phytoremediation in decreasing Cd concentrations in paddies is limited.A pot experiment in greenhouse was conducted to evaluate the effect of rice intercropping with two wetland plants(Pontederia cordata and Canna indica)under different soil Cd levels(0,1,10,and 25 mg kg^(-1))on rice growth and Cd accumulation and translocation.The results showed that rice intercropping with the two wetland plants significantly improved plant height,tiller,and biomass of rice,but reduced Cd bioconcentration factors(BCFs)and Cd concentrations in rice and wetland plants.Compared with rice monocropping,the BCF in rice grain under 25 mg kg^(-1)soil Cd level significantly decreased by 54.39%and 59.65%in the systems of rice intercropping with C.indica and P.cordata,respectively.In addition,intercropping inhibited the increase in BCFs in rice and wetland plants under increasing soil Cd levels.In conclusion,the systems of rice intercropping with P.cordata and C.indica can be considered two new and effective approaches for ameliorating Cd pollution in paddies,as well as minimizing Cd accumulation in rice and improving food safety.Of the two intercropping systems,rice intercropping with P.cordata performed better than intercropping with C.indica.
基金the National Basic Research Program of China(No.2006CB100203)the National Natural Science Foundation of China(Grant No.30560034)+1 种基金the Advanced Cooperation Research Program between China and France(PRA E 01-02)the International Cooperation Research Foundation of Yunnan Province,China(No.2002GH14).
文摘This paper studied the relationship between heavy metal concentrations of herbaceous plants and soils at four Pb-Zn mining sites in Yunnan,China.50 herbaceous plant samples of 9 plant species from 4 families and 50 soil samples were collected and then ana1yzed for the tota1 concentrations of Pb,Cd,and Zn.The results showed that the average concentrations of Pb,Cd,and Zn in soil samples were 3772.83,168.81,and 5385.65 mg/kg,respectively.The average concentrations of Pb,Cd,and Zn were 395.68,28.14,and 1664.20 mg/kg in the shoots,and 924.12,57.25,and 1778.75 mg/kg in the roots,respectively.Heterospecific plants at the same site and conspecific plants at various sites had different average levels of Pb,Cd,and Zn,both in the shoots and the roots.Enrichment coefficients of Pb,Cd,and Zn were greater than 1 in 2,3,and 9 herbaceous plant samples,respectively.Translocation factors of Pb,Cd,and Zn were greater than 1 in 10,17,and 25 herbaceous plant samples,respectively.In all 50 samples,the concentrations of Pb,Cd,and Zn between the shoots and the roots,the shoots,and the soils,and the roots and the soils had significant positive relationships.
