Flooded soil samples were collected in the typical area of the Yangtze Delta Region; fractions of heavy metals in flooded and air dried samples were measured with BCR sequential extraction method and atomic absorption...Flooded soil samples were collected in the typical area of the Yangtze Delta Region; fractions of heavy metals in flooded and air dried samples were measured with BCR sequential extraction method and atomic absorption spectrometry. In flooded soils, fractions of heavy metals increased in the order of acid soluble 〈 oxidizable 〈 reducible 〈 residual. The acid soluble and reducible fractions significantly decreased but residual fraction significantly increased when the samples were air dried. The data obtained from air dried soil samples could not accurately represent the speciation of heavy metals in flooded field conditions.展开更多
Changes in soil organic carbon （SOC） of rice paddies in China were simulated from 1980 to 2000 by linking a coupled bio-physical model to GIS database. The coupled model consists of two sub-models including Crop-C f...Changes in soil organic carbon （SOC） of rice paddies in China were simulated from 1980 to 2000 by linking a coupled bio-physical model to GIS database. The coupled model consists of two sub-models including Crop-C for simulating net primary productivity and hence residue retention and Soil-C for computing the turnover rates of SOC. The GIS database included parameters of climate, soils and agricultural activities with the resolution of 10 km × 10 km. Model simulation indicated that Chinese rice paddies covering 22.6 Mha sequestrated a considerable amount of C, about 0.15 ± 0.07 Pg C from 1980 to 2000. Annual sequestration rate increased sharply from -180 ± 45 kg C ha^-1 year^-1 in 1980 to 440 ± 170 kg C ha^-1 year^-1 in 1989. Thereafter, a steaziy sequestration rate of 460 ± 170 kg C ha^-1 year^-1 occurred till 1994 and declined since then. Approximately 84% of the Chinese rice paddies sequestrated carbon, while 15% lost carbon and 1% kept balance over the 20 years. Great SOC sequestration occurred in eastern, southern and central China, while a slight decline of SOC existed in some regions of northeastern and southwestern China.展开更多
Rice paddy soil is recognized as the hotspot of mercury（Hg） methylation, which is mainly a biotic process mediated by many abiotic factors. In this study, effects of key soil properties on the production and bioaccu...Rice paddy soil is recognized as the hotspot of mercury（Hg） methylation, which is mainly a biotic process mediated by many abiotic factors. In this study, effects of key soil properties on the production and bioaccumulation of Hg and methylmercury（MeHg） in Hg-contaminated rice paddies were investigated. Rice and soil samples were collected from the active Hg smelting site and abandoned Hg mining sites（a total of 124 paddy fields） in the Wanshan Mercury Mine, China. Total Hg（THg） and MeHg in soils and rice grains, together with sulfur（S）,selenium（Se）, organic matter（OM）, nitrogen（N）, phosphorus（P）, mineral compositions（e.g., SiO2, Al2O3 and Fe2O3） and pH in soils were quantified. The results showed that long-term Hg mining activities had resulted in THg and MeHg contaminations in soil-rice system. The newly-deposited atmospheric Hg was more readily methylated relative to the native Hg already in soils, which could be responsible for the elevated MeHg levels in soils and rice grains around the active artificial Hg smelting site. The MeHg concentrations in soils and rice grains showed a significantly negative relationship with soil N/Hg, S/Hg and OM/Hg ratio possibly due to the formation of low-bioavailability Hg–S（N）–OM complexes in rhizosphere. The Hg–Se antagonism undoubtedly occurred in soil-rice system, while its role in bioaccumulation of MeHg in the MeHg-contaminated rice paddies was minor. However, other soil properties showed less influence on the production and bioaccumulation of MeHg in rice paddies located at the Wanshan Mercury Mine zone.展开更多
In the current study,the ecosystem services(ES) of conventional and organic rice paddies in Wannian,Jiangxi Province,China are investigated.First,the ES at the field level under organic and conventional paddies were i...In the current study,the ecosystem services(ES) of conventional and organic rice paddies in Wannian,Jiangxi Province,China are investigated.First,the ES at the field level under organic and conventional paddies were investigated.Total economic value of ES in organic rice paddies was 30093.08 yuan RMB/ha per year and that of conventional rice paddies was 22 793.31 yuan RMB/ha per year.The total indirect value of ES was 14 813.7 yuan RMB/ha per year in organic rice paddies and 12 424.56 yuan RMB/ha per year in conventional ones.There were significant differences between organic and conventional rice paddies for the economic values.Then,this economic information was used to extrapolate and to calculate the total and indirect value of ES from rice paddies in Wangnian.The total and indirect economic values of ES from conventional rice paddies in Wannian were 6791 million and 3702 million yuan RMB per year respectively,and the total and indirect economic values of ES from organic rice paddies in Wannian were 1311 million and 646 million yuan RMB per year.If half the area had being converted to organic farming in Wannian,the total and indirect economic values of ES from conventional rice paddies were 3397 million and 1851 million yuan RMB per year,and the total and indirect economic values of ES from organic rice paddies were 5794 million and 2852 million yuan RMB per year.Finally,the total economic value of ES in rice paddies in Wannian was demonstrated through geographic information system techniques.展开更多
Rice(Oryza sativa L.)paddies are increasingly threatened by cadmium(Cd)pollution,and potentially serve as CH_(4)emitters to the atmosphere.Remediation agents widely mitigate Cd pollution in paddy soil,however,we know ...Rice(Oryza sativa L.)paddies are increasingly threatened by cadmium(Cd)pollution,and potentially serve as CH_(4)emitters to the atmosphere.Remediation agents widely mitigate Cd pollution in paddy soil,however,we know little about their regulations on CH_(4)emission.Here,via adding biochar(B),sulfhydryl-modified palygorskite(SMP),and selenium foliar fertilizer(SFF),we conducted a pot experiment to investigate soil and rice Cd contents together with in-situ CH_(4)f luxes.Compared to CK,the addition of SMP,SFF,and B-SMP reduced Cd in brown rice by 25%to 50%,25%,and 50%to 75%,respectively.Agents 7%B,7%B-0.01%SMP,and SFF reduced CH_(4)emissions by 8.46%,5.30%,and 4.11%,respectively.CH_(4)emission increased gradually along the growing season,with the cumulative CH_(4)fluxes ranging between 338.82 and 619.13 kg hm^(-2).Our results highlight that mixed 7%B-0.01%SMP and SFF showed collaborative eff ects on Cd remediation and CH_(4)emission.This study reveals the feasibility of reducing Cd pollution and CH_(4)emission in karst rice paddies,which hopes to supplement the knowledge of collaborative controls on soil remediation and carbon emission.展开更多
Based on reference review, this study investigated ecosystem services supported by 10 typical rice paddies in six rice planting regions of China. The services were primary production, gas regulation, nitrogen transfor...Based on reference review, this study investigated ecosystem services supported by 10 typical rice paddies in six rice planting regions of China. The services were primary production, gas regulation, nitrogen transformation, soil organic matter accumulation, and water regulation and flood control. The results indicated that grain production of the 10 rice paddies was between 4.71 and 12.18 t ha^-1 y^-1; straw production was 4.65 to 9.79 t ha^-1 y^-1; gas regulation was calculated to emit O2 ranging from 8.27 to 19.69 t ha^-1 y^-1 and to assimilate greenhouse gases ranging from -2.13 to 19.24 t ha^-1 y^-1 （in CO2 equivalent）; nitrogen transformation was estimated as nitrogen input ranging from 209.70 to 513.93 kg N ha^-1 y^-1 and nitrogen output of 112.87 to 332.69 kg N ha^-1 y^-1; soil organic matter accumulation was calculated to be between 0.69 and 4.88 t C ha^-1 y^-1; water regulation was estimated to consume water resources of 19875 m3 ha^-1 y^-1 and to support water resources of 6430 m3 ha^-1 y^-1; and flood control of several of the rice paddies was calculated to be 1500 m3 ha^-1 y^-1. The integrated economic value of ecosystem services of these rice paddies was estimated at USD 8605–21 405 ha^-1 y^-1, of which 74%–89% of the value can be ascribed to ecosystem services outside primary production. The results also indicated that the integrated economic value of the ecosystem services of the 10 rice paddies was higher when nitrogen fertilizer was applied in the range of 275 to 297 kg N ha^-1. Until now, the economic value of the rice paddy ecosystem has been underestimated as only the economic value of grain and straw production was previously calculated. As more and more forest land and grassland is lost to urban and industrial use, cropland and especially rice paddies, will become more ecologically important to society. The economic value of ecosystem services supplied by rice paddies, outside primary production, are worthy of increased research attention.展开更多
A number of ancient charred paddies with a 14C dating of about 5900 a BP were recovered in the sixth excavation at Chuodun Site and are assigned to the Majiabang culture(7-6 ka BP).To understand their formation mechan...A number of ancient charred paddies with a 14C dating of about 5900 a BP were recovered in the sixth excavation at Chuodun Site and are assigned to the Majiabang culture(7-6 ka BP).To understand their formation mechanism,the ancient charred paddies were compared to modern paddies using FT-IR spectrum and thermaogravimetric analysis.At the same time,modern charred paddies were made in helium by the laboratory method,and the structural characteristics of them and the ancient ones were revealed using CP/MAS-13C-NMR.Our results show there are more aromatic moieties in ancient charred paddies compared to modern paddies.The aliphatic components of modern charred paddies decrease continuously,accompanied by the accumulation of aromatic components,when the duration and temperature of oxidation increase,and the structure buildings of modern charred paddies are more similar to ancient ones.Given the planting manner of paddies during Majiabang culture period,these ancient charred paddies might be a result of the original farming mode involving fire.展开更多
From rice paddies to poultry farms,an ambitious generation of Tanzanian youth is cultivating dreams of agricultural entrepreneurship A tender breeze sweeps across Zanzibar’s golden paddies at sunrise,carrying with it...From rice paddies to poultry farms,an ambitious generation of Tanzanian youth is cultivating dreams of agricultural entrepreneurship A tender breeze sweeps across Zanzibar’s golden paddies at sunrise,carrying with it the calm rhythm of a new day.展开更多
From July to September of 1990,CH_4 flux measurements were made in Lin'an rice paddies using gradient profile techniques.Some characteristics of the turbulence structure under the stable conditions have been verif...From July to September of 1990,CH_4 flux measurements were made in Lin'an rice paddies using gradient profile techniques.Some characteristics of the turbulence structure under the stable conditions have been verified in the surface layer according to the in situ measurements.The semi-empirical turbulent parameters β_m,β_h and β_c and their changes with the stability parameter Ri are given.Observed results indicate that CH_4 flux in the rice-paddy is mainly decided by the methnogenesis and the process of CH4 transport from internal soils to the atmosphere,and that the CH_4 vertical transfer is depressed in the stable surface layer.The CH_4 flux shows that its obvious diurnal changes,and the mean CH_4 flux are higher in nighttime and lower in daytime,and the peaks appear at about 2000 BST at night and 0300 BST in the early morning,respectively.The mean value of CH_4 flux is about 4.18±2.3 mg/m^2 h.展开更多
Adoption of Chinese hybrid rice boosts food security in Madagascar As the sun rises over the rice paddies of Mahitsy,Ramos Rakotorinina breathes in the cool morning air,watching the emerald green shoots of Chinese hyb...Adoption of Chinese hybrid rice boosts food security in Madagascar As the sun rises over the rice paddies of Mahitsy,Ramos Rakotorinina breathes in the cool morning air,watching the emerald green shoots of Chinese hybrid rice sway softly in the breeze.展开更多
The demand for pesticides in China hasshrunk this year. The resulting fiercer competitionbetween herbicide varieties has ledto a significant price reduction in mostherbicides. The sales and the price of threerice padd...The demand for pesticides in China hasshrunk this year. The resulting fiercer competitionbetween herbicide varieties has ledto a significant price reduction in mostherbicides. The sales and the price of threerice paddy herbicides including butachlor, quinclorac and cinosulfuron have grownhowever. This phenomenon may be closelyrelated to the fact that rice is the most importantgrain crop in China. Rice grows展开更多
Winter planting green manures in southern China effectively improve soil properties and rice production through microbial community construction.However,the effects of soil communities of arbuscular mycorrhizal fungi(...Winter planting green manures in southern China effectively improve soil properties and rice production through microbial community construction.However,the effects of soil communities of arbuscular mycorrhizal fungi(AMF)from different winter planting green manures on the soil properties and post-cropping rice production remain unclear.In this study,the soil AMF communities of three common winter planting patterns in southern China,winter fallow,winter ryegrass(Lolium multiflorum L.),and winter Chinese milk vetch(Astragalus sinicus L.),were explored and their effects on post-cropping rice production were investigated.Compared with winter fallow,the winter ryegrass and winter Chinese milk vetch patterns could alleviate soil acidification,significantly increase soil AMF spore density,and improve the soil AMF community structure.Based on sterilized soil,rice production indicators such as thousandseed weight,theoretical yield,and the grain amylose and total sugar contents of rice inoculated with AMF spores from winter Chinese milk vetch soil were 6.68–53.57%higher than those without AMF inoculation.Rice panicle weight,seed setting rate,and theoretical yield were 15.38–22.71%higher in the treatment with AMF spores from winter ryegrass soil than in the treatments with no AMF inoculation.In addition,the protein,amylose,and total sugar contents of rice grains were 14.92,104.82,and 802.23 mg kg^(–1),respectively,which were 31.31,14.25 and 34.47%higher than those without AMF inoculation.The AMF community dominated by Glomus and Acaulospora in winter Chinese milk vetch had a more positive effect on the improvement of rice yield,while the AMF community dominated by Glomus in winter ryegrass soil was more conducive to rice quality improvement.These findings have revealed the critical role of AMF communities from green manure in rice production,which lays the theoretical basis for a promising strategy to promote the sustainable development of southern winter agriculture.展开更多
In order to identify the nutrient level and environmental quality of paddy fields in Wanchang area,and to provide scientific basis and technical support for planting rice in Wanchang area, the soil geochemicalsurvey w...In order to identify the nutrient level and environmental quality of paddy fields in Wanchang area,and to provide scientific basis and technical support for planting rice in Wanchang area, the soil geochemicalsurvey was carried out, 30 samples were collected from paddy soil in Wanchang area, and 20 elements(indicators) were analyzed. The characterization of the elemental content of soils in the study area was carriedout, and the geochemical level for soil nutrients, the geochemical level for the soil environment, and thecomprehensive geochemical level of soil quality were evaluated. The results showed that the average valuesof K content and pH of the soil in the study area were smaller than the background values of Jilin Province,and the average values of 18 elements including N, P, Ca, S, Pb, Zn etc. were bigger than the backgroundvalues of Jilin Province. The results of the evaluation of soil single element nutrient in the study area showedthat the available state nutrient levels of Mn, Zn, Cu, and K increased compared with the total amounts ofnutrients level, with Cu increasing the most;the available state nutrient level of N, P, B, and Mo decreasedcompared with the total amounts of nutrients level, with Mo decreasing the most. The comprehensive levelof soil nutrients geochemistry in paddy fields was mainly Level III (medium), accounting for 53.33%, andthe low abundance level was caused by the lack of P element;the comprehensive level of soil environmentalgeochemistry was mainly Level I (clean), accounting for 96.67%, with only slight pollution caused byCd. The comprehensive geochemical level of soil quality was mainly Level II, accounting for 66.67%.Suggestions were put forward for the rational utilization of soil resources in paddy fields in the study area.展开更多
This study aimed to explore the effect of different proportions of organic fertilizer replacing chemical fertilizer on the bacterial community and metabolic function in paddy fields.The 16S rRNA absolute quantitative ...This study aimed to explore the effect of different proportions of organic fertilizer replacing chemical fertilizer on the bacterial community and metabolic function in paddy fields.The 16S rRNA absolute quantitative sequencing method was employed to study the response characteristics of soil bacterial community composition and species absolute abundance to environmental factors under three fertilization treatments[chemical fertilizer(NPK),organic fertilizer replacing 30%of chemical fertilizer(30M,estimated in terms of pure nitrogen,same below),and organic fertilizer replacing 60%of chemical fertilizer(60M)]for two consecutive years.Furthermore,the changes of bacterial metabolic functions of different fertilization treatments were predicted by PICRUSt2.The results showed that replacing chemical fertilizer with organic fertilizer at different proportions significantly increased the total nitrogen(TN),total potassium(TK),hydrolyzable nitrogen(HN),soil organic carbon(SOC),and significantly decreased the soil bulk density(SBD).Moreover,60M demonstrated better performance than 30M.Different fertilization treatments did not cause significant difference in soil bacterial richness index(Chao1)or diversity index(Shannon)but significantly affected bacterial community composition and species abundance.Particularly,60M significantly increased the abundance of 227 species,and it increased the total bacterial abundance by 25.30%and 56.58%compared with NPK and 30M,respectively.Redundancy analysis and Spearman correlation analysis revealed that SOC,TN,and AK were the key factors for shaping specific bacterial community structures under different fertilization treatments.The 60M treatment significantly increased the abundance of bacterial species involved in xenobiotic biodegradation and metabolism,amino acid metabolism,and lipid metabolism,thus improving the metabolic functions of soil microorganisms.展开更多
Accurate and timely large-scale paddy rice maps with remote sensing are essential for crop monitoring and management and are used for assessing its impacts on food security,water resource management,and transmission o...Accurate and timely large-scale paddy rice maps with remote sensing are essential for crop monitoring and management and are used for assessing its impacts on food security,water resource management,and transmission of zoonotic infectious diseases.Optical image-based paddy rice mapping studies employed the unique spectral feature during the flooding/transplanting period of paddy rice.However,the lack of high-quality observations during the flooding/transplanting stage caused by rain and clouds and spectral similarity between paddy rice and natural wetlands often introduce errors in paddy rice identification,especially in paddy rice and wetland coexistent areas.In this study,we used a knowledge-based algorithm and time series observation from optical images(Sentinel-2 and Landsat 7/8)and microwave images(Sentinel-1)to address these issues.The final 10-m paddy rice map had user’s accuracy,producer’s accuracy,F1-score,and overall accuracy of 0.91±0.004,0.74±0.010,0.82,and 0.98±0.001(±value is the standard error),respectively.Over half(62.0%)of the paddy rice pixels had a confidence level of 1(detected by both optical images and microwave images),while 38.0%had a confidence level of 0.5(detected by either optical images or microwave images).The estimated paddy rice area in northeast China for 2020 was 60.83±0.86×10^(3)km^(2).Provincial and municipal rice areas in our data set agreed well with other existing paddy rice data sets and the Agricultural Statistical Yearbooks.These findings indicate that knowledge-based paddy rice mapping algorithms and a combination of optical and microwave images hold great potential for timely and frequently accurate paddy rice mapping in large-scale complex landscapes.展开更多
In natural ecosystems,the timely abscission of seeds in wild plants is a crucial adaptive trait that contributes to reproductive success,population renewal,and colony expansion(Thurber et al.2010).In contrast,the tend...In natural ecosystems,the timely abscission of seeds in wild plants is a crucial adaptive trait that contributes to reproductive success,population renewal,and colony expansion(Thurber et al.2010).In contrast,the tendency for high seed shattering in domesticated crops,such as rice,not only reduces paddy yield but also complicates mechanized harvesting.展开更多
The conversion of saline-alkali soils into paddy fields for long-term rice cultivation involves multiple disturbances,and as a result,soil microbial communities are altered to adapt to changing environmental condition...The conversion of saline-alkali soils into paddy fields for long-term rice cultivation involves multiple disturbances,and as a result,soil microbial communities are altered to adapt to changing environmental conditions.However,a comprehensive understanding of the succession of soil bacterial communities that occurs during this process is still lacking.In the present study,we utilized data obtained from paddy fields of different rice cultivation years(0-23 years)to investigate the compositional and functional succession of soil bacterial communities.We focused on core bacterial taxa that were specifically enriched at different successional stages.Generalized joint attribute modeling(GJAM)was used to identify core bacterial taxa.Results indicated that the bare saline-alkali soil(0 year,prior to any rice cultivation)shared few core amplicon sequence variants(ASVs)with paddy fields.In the bare saline-alkali soil,Longimicrobiaceae from the phylum Gemmatimonadetes was dominant,while the dominance was subsequently replaced by Burkholderiaceae and Pedosphaeraceae--phyla affiliated with Proteobacteria and Verrucomicrobia--after 5 and 23 years of rice cultivation,respectively.The relative abundances of nitrogen metabolism functions in the core bacterial communities of the bare saline-alkali soil were higher than those at other successional stages,while sulfur metabolism functions exhibited the opposite trend.These indicated that the role of the core bacterial taxa in mediating nutrient cycling also evolved and adapted to changing soil conditions as rice cultivation was established.Redundancy analysis(RDA)indicated that the composition of the core bacterial community in paddy fields with rice cultivation for 0,2 and 4,6,8,10,and 12,and 20 and 23 years were driven by soil nitrate nitrogen content,pH,available phosphorus content,and the ratio of total carbon to total nitrogen,respectively.In summary,the present study provides insights into the succession of soil bacterial communities and core bacterial taxa that occurs during long-term rice cultivation.展开更多
Cadmium ion(Cd^(2+))detection technology plays a prominent role in food safety and human health.Herein,we designed and constructed an 2-aminoethyl dihydrogen phosphate(AEP)@upconversion nanoparticles(UCNPs)fluorescenc...Cadmium ion(Cd^(2+))detection technology plays a prominent role in food safety and human health.Herein,we designed and constructed an 2-aminoethyl dihydrogen phosphate(AEP)@upconversion nanoparticles(UCNPs)fluorescence sensor for quantitative detection of Cd^(2+)in paddy rice based on inner filter effect(IFE)combined with enzyme inhibition mechanism.The AEP modification UCNPs can offer a stable fluorescence donor at 658 nm and be quenched by the oxidized tetramethylbenzidine(oxTMB)catalyzed by horseradish peroxidase(HRP)enzymes.Without addition of Cd^(2+),the fluorescence of AEP@UCNPs fluorescence sensor was weaken due to the IFE between AEP@UCNPs and oxTMB.With addition of Cd^(2+),HRP enzyme activity was inhibited by Cd^(2+),leading to the decreased oxTMB,resulting in the enhance upconversion fluorescence intensity.As a result,the fluorescence intensity signal at 658 nm of the IFE-based AEP@UCNPs fluorescence sensor increased linearly with the increase in Cd^(2+)in a wide range from 0.5μmol/L to 6μmol/L and the limit of detection(LOD)was 24.6 n mol/L.In addition,our proposed IFE-based AEP@UCNPs fluorescence sensor can achieve Cd^(2+)detection in paddy rice in 30 min.展开更多
Zinc(Zn)is an essential micronutrient for both plants and humans.Zn deficiency is common in many paddy fields and reduces yield and grain Zn content(GZC).To accelerate breeding for improved GZC and Zn deficiency toler...Zinc(Zn)is an essential micronutrient for both plants and humans.Zn deficiency is common in many paddy fields and reduces yield and grain Zn content(GZC).To accelerate breeding for improved GZC and Zn deficiency tolerance(ZDT)rice varieties,it is important to identify genes regulating Zn homeostasis.In this study,a member of the Ser/Thr protein phosphatase family,LOC_Os07g48840(named as OsGZ7),was found to contributed to ZDT and GZC in rice.The expression of OsGZ7 in roots and shoots was inhibited by Zn deficiency and toxicity,but induced by iron(Fe),manganese(Mn),and copper(Cu)deficiency,as well as chromium toxicity.OsGZ7 localized to the cytoplasm and was expressed in all tissues during the tillering,flowering,and grain-filling stages,particularly in the leaf blade and leaf sheath.At the seedling stage,knockout of OsGZ7 enhanced ZDT and increased Zn accumulation in both roots and shoots.At the maturity stage,knockout of OsGZ7 enhanced GZC,while overexpression of OsGZ7 reduced GZC.RNA-seq analysis suggested that OsGZ7 might regulate Zn homeostasis by affecting metal binding,hormone signal transduction,and oxidoreductase activity.Taken together,our findings indicate that OsGZ7 contributes to ZDT and Zn accumulation in rice.展开更多
Paddy soil is frequently flooded,which leads to anaerobic decomposition of soil organic matter(SOM)to produce CO_(2) and CH_(4).Currently,there is limited research about the impact of nanoparticles on anaerobic SOM de...Paddy soil is frequently flooded,which leads to anaerobic decomposition of soil organic matter(SOM)to produce CO_(2) and CH_(4).Currently,there is limited research about the impact of nanoparticles on anaerobic SOM decomposition and CH_(4) production in paddy soil.This study investigates the effects of iron oxide nanoparticles(Fe_(3)O_(4) NPs)and multi-walled carbon nanotubes(MWCNTs)on anaerobic SOM decomposition in two paddy soils.The findings showed that addition of nanoparticles(Fe_(3)O_(4) NPs:0.08%and 0.3%;MWCNTs:0.05%and 0.2%)reduced methane production by 7.48%−31.72%in Guiyang soil and 3.32%−31.24%in Fuyang soil,with decrease in SOM decomposition of 32.19%−47.87%and 19.60%−33.09%,respectively.However,the CH_(4)/TIC(total inorganic carbon)ratio was elevated(by 3.17%to 61.92%)after nanoparticles amendment,suggested that TIC production was more significantly suppressed than CH_(4).The Prolixibacteraceae,which usually involve in organic macromolecule decomposition,decreased in relative abundance with inhibition of CH_(4) production by nanoparticles in both soils,suggesting their sensitivity to nanoparticles.In contrast,the relative abundances of many microbial populations increased with the intensified inhibition of soil mineralization by nanoparticles in both soils.Especially,Sedimentibacter and Melioribacterae increased with inhibition of CH_(4) by nanoparticles,and Clostridiaceae,Minicystis as well as Rhodomicrobium increased with the CH_(4)/TIC ratio in both soils,probably because they might provide substrates for methanogens.These results suggested that nanoparticles not only inhibit the decomposition of SOM but also change the fate of decomposed carbon through modulating microbial populations,leading to a substantial increase in the proportion of CH_(4) produced from SOM decomposition.展开更多
基金funding from the Natural Science Foundation of China(No.41101491)
文摘Flooded soil samples were collected in the typical area of the Yangtze Delta Region; fractions of heavy metals in flooded and air dried samples were measured with BCR sequential extraction method and atomic absorption spectrometry. In flooded soils, fractions of heavy metals increased in the order of acid soluble 〈 oxidizable 〈 reducible 〈 residual. The acid soluble and reducible fractions significantly decreased but residual fraction significantly increased when the samples were air dried. The data obtained from air dried soil samples could not accurately represent the speciation of heavy metals in flooded field conditions.
基金Project supported by the Knowledge Innovation Program of the Chinese Academy of, Sciences (No. KZCX1-SW-01-13)the National Natural Science Foundation of China (No. 40431001)the National Key Basic Research Support Foundation of China (No. 2002CB412500).
文摘Changes in soil organic carbon （SOC） of rice paddies in China were simulated from 1980 to 2000 by linking a coupled bio-physical model to GIS database. The coupled model consists of two sub-models including Crop-C for simulating net primary productivity and hence residue retention and Soil-C for computing the turnover rates of SOC. The GIS database included parameters of climate, soils and agricultural activities with the resolution of 10 km × 10 km. Model simulation indicated that Chinese rice paddies covering 22.6 Mha sequestrated a considerable amount of C, about 0.15 ± 0.07 Pg C from 1980 to 2000. Annual sequestration rate increased sharply from -180 ± 45 kg C ha^-1 year^-1 in 1980 to 440 ± 170 kg C ha^-1 year^-1 in 1989. Thereafter, a steaziy sequestration rate of 460 ± 170 kg C ha^-1 year^-1 occurred till 1994 and declined since then. Approximately 84% of the Chinese rice paddies sequestrated carbon, while 15% lost carbon and 1% kept balance over the 20 years. Great SOC sequestration occurred in eastern, southern and central China, while a slight decline of SOC existed in some regions of northeastern and southwestern China.
基金supported by the National Natural Science Foundation of China (No.41763017)the Program Foundation of Institute for Scientific Research of Karst Area of NSFC-GZGOV (No.U1612442)+2 种基金the Science and Technology Planning Project of Guizhou Province (No.Qiankehe-[2018]2336)the Key Discipline Construction Project,Guizhou (No.ZDXK [2016]11)the Topclass Discipline Construction Project of Ecology in Guizhou Province (No.GNYL[2017]007)
文摘Rice paddy soil is recognized as the hotspot of mercury（Hg） methylation, which is mainly a biotic process mediated by many abiotic factors. In this study, effects of key soil properties on the production and bioaccumulation of Hg and methylmercury（MeHg） in Hg-contaminated rice paddies were investigated. Rice and soil samples were collected from the active Hg smelting site and abandoned Hg mining sites（a total of 124 paddy fields） in the Wanshan Mercury Mine, China. Total Hg（THg） and MeHg in soils and rice grains, together with sulfur（S）,selenium（Se）, organic matter（OM）, nitrogen（N）, phosphorus（P）, mineral compositions（e.g., SiO2, Al2O3 and Fe2O3） and pH in soils were quantified. The results showed that long-term Hg mining activities had resulted in THg and MeHg contaminations in soil-rice system. The newly-deposited atmospheric Hg was more readily methylated relative to the native Hg already in soils, which could be responsible for the elevated MeHg levels in soils and rice grains around the active artificial Hg smelting site. The MeHg concentrations in soils and rice grains showed a significantly negative relationship with soil N/Hg, S/Hg and OM/Hg ratio possibly due to the formation of low-bioavailability Hg–S（N）–OM complexes in rhizosphere. The Hg–Se antagonism undoubtedly occurred in soil-rice system, while its role in bioaccumulation of MeHg in the MeHg-contaminated rice paddies was minor. However, other soil properties showed less influence on the production and bioaccumulation of MeHg in rice paddies located at the Wanshan Mercury Mine zone.
基金supported by GEF/FAO project"Rice-fish GIAHS Conservation and Adaptive Management"(GCP/GCO/212/GEF)
文摘In the current study,the ecosystem services(ES) of conventional and organic rice paddies in Wannian,Jiangxi Province,China are investigated.First,the ES at the field level under organic and conventional paddies were investigated.Total economic value of ES in organic rice paddies was 30093.08 yuan RMB/ha per year and that of conventional rice paddies was 22 793.31 yuan RMB/ha per year.The total indirect value of ES was 14 813.7 yuan RMB/ha per year in organic rice paddies and 12 424.56 yuan RMB/ha per year in conventional ones.There were significant differences between organic and conventional rice paddies for the economic values.Then,this economic information was used to extrapolate and to calculate the total and indirect value of ES from rice paddies in Wangnian.The total and indirect economic values of ES from conventional rice paddies in Wannian were 6791 million and 3702 million yuan RMB per year respectively,and the total and indirect economic values of ES from organic rice paddies in Wannian were 1311 million and 646 million yuan RMB per year.If half the area had being converted to organic farming in Wannian,the total and indirect economic values of ES from conventional rice paddies were 3397 million and 1851 million yuan RMB per year,and the total and indirect economic values of ES from organic rice paddies were 5794 million and 2852 million yuan RMB per year.Finally,the total economic value of ES in rice paddies in Wannian was demonstrated through geographic information system techniques.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB40020200)the National Natural Science Foundation of China(41663015,42273021)+4 种基金Guizhou Science and Technology Cooperation Basic Project([2020]1Y188)the construction project of Key Laboratory of State Ethnic Aff airs Commission([2020]No 0.91 of DDA office)the Innovation Team Project of Guizhou Higher Education([2022]013)Foundation of Guizhou Minzu University(GZMU[2019]YB11)Thanks to the support of the independent deployment project of the State Key Laboratory of Environmental Geochemistry。
文摘Rice(Oryza sativa L.)paddies are increasingly threatened by cadmium(Cd)pollution,and potentially serve as CH_(4)emitters to the atmosphere.Remediation agents widely mitigate Cd pollution in paddy soil,however,we know little about their regulations on CH_(4)emission.Here,via adding biochar(B),sulfhydryl-modified palygorskite(SMP),and selenium foliar fertilizer(SFF),we conducted a pot experiment to investigate soil and rice Cd contents together with in-situ CH_(4)f luxes.Compared to CK,the addition of SMP,SFF,and B-SMP reduced Cd in brown rice by 25%to 50%,25%,and 50%to 75%,respectively.Agents 7%B,7%B-0.01%SMP,and SFF reduced CH_(4)emissions by 8.46%,5.30%,and 4.11%,respectively.CH_(4)emission increased gradually along the growing season,with the cumulative CH_(4)fluxes ranging between 338.82 and 619.13 kg hm^(-2).Our results highlight that mixed 7%B-0.01%SMP and SFF showed collaborative eff ects on Cd remediation and CH_(4)emission.This study reveals the feasibility of reducing Cd pollution and CH_(4)emission in karst rice paddies,which hopes to supplement the knowledge of collaborative controls on soil remediation and carbon emission.
基金Strategic Priority Research Program of the Chinese Academy of Sciences (XDA05050203)National Natural Science Foundation of China (31140048, 30770410 and 31070384)Innovation Project of Institute of Geographic Sciences and Natural Resources Research, CAS (200905010)
文摘Based on reference review, this study investigated ecosystem services supported by 10 typical rice paddies in six rice planting regions of China. The services were primary production, gas regulation, nitrogen transformation, soil organic matter accumulation, and water regulation and flood control. The results indicated that grain production of the 10 rice paddies was between 4.71 and 12.18 t ha^-1 y^-1; straw production was 4.65 to 9.79 t ha^-1 y^-1; gas regulation was calculated to emit O2 ranging from 8.27 to 19.69 t ha^-1 y^-1 and to assimilate greenhouse gases ranging from -2.13 to 19.24 t ha^-1 y^-1 （in CO2 equivalent）; nitrogen transformation was estimated as nitrogen input ranging from 209.70 to 513.93 kg N ha^-1 y^-1 and nitrogen output of 112.87 to 332.69 kg N ha^-1 y^-1; soil organic matter accumulation was calculated to be between 0.69 and 4.88 t C ha^-1 y^-1; water regulation was estimated to consume water resources of 19875 m3 ha^-1 y^-1 and to support water resources of 6430 m3 ha^-1 y^-1; and flood control of several of the rice paddies was calculated to be 1500 m3 ha^-1 y^-1. The integrated economic value of ecosystem services of these rice paddies was estimated at USD 8605–21 405 ha^-1 y^-1, of which 74%–89% of the value can be ascribed to ecosystem services outside primary production. The results also indicated that the integrated economic value of the ecosystem services of the 10 rice paddies was higher when nitrogen fertilizer was applied in the range of 275 to 297 kg N ha^-1. Until now, the economic value of the rice paddy ecosystem has been underestimated as only the economic value of grain and straw production was previously calculated. As more and more forest land and grassland is lost to urban and industrial use, cropland and especially rice paddies, will become more ecologically important to society. The economic value of ecosystem services supplied by rice paddies, outside primary production, are worthy of increased research attention.
基金Supported by the National Natural Science Foundation of China (Grant No.40571088)
文摘A number of ancient charred paddies with a 14C dating of about 5900 a BP were recovered in the sixth excavation at Chuodun Site and are assigned to the Majiabang culture(7-6 ka BP).To understand their formation mechanism,the ancient charred paddies were compared to modern paddies using FT-IR spectrum and thermaogravimetric analysis.At the same time,modern charred paddies were made in helium by the laboratory method,and the structural characteristics of them and the ancient ones were revealed using CP/MAS-13C-NMR.Our results show there are more aromatic moieties in ancient charred paddies compared to modern paddies.The aliphatic components of modern charred paddies decrease continuously,accompanied by the accumulation of aromatic components,when the duration and temperature of oxidation increase,and the structure buildings of modern charred paddies are more similar to ancient ones.Given the planting manner of paddies during Majiabang culture period,these ancient charred paddies might be a result of the original farming mode involving fire.
文摘From rice paddies to poultry farms,an ambitious generation of Tanzanian youth is cultivating dreams of agricultural entrepreneurship A tender breeze sweeps across Zanzibar’s golden paddies at sunrise,carrying with it the calm rhythm of a new day.
基金The project is sponsored by the National Natural Science Foundation of China.
文摘From July to September of 1990,CH_4 flux measurements were made in Lin'an rice paddies using gradient profile techniques.Some characteristics of the turbulence structure under the stable conditions have been verified in the surface layer according to the in situ measurements.The semi-empirical turbulent parameters β_m,β_h and β_c and their changes with the stability parameter Ri are given.Observed results indicate that CH_4 flux in the rice-paddy is mainly decided by the methnogenesis and the process of CH4 transport from internal soils to the atmosphere,and that the CH_4 vertical transfer is depressed in the stable surface layer.The CH_4 flux shows that its obvious diurnal changes,and the mean CH_4 flux are higher in nighttime and lower in daytime,and the peaks appear at about 2000 BST at night and 0300 BST in the early morning,respectively.The mean value of CH_4 flux is about 4.18±2.3 mg/m^2 h.
文摘Adoption of Chinese hybrid rice boosts food security in Madagascar As the sun rises over the rice paddies of Mahitsy,Ramos Rakotorinina breathes in the cool morning air,watching the emerald green shoots of Chinese hybrid rice sway softly in the breeze.
文摘The demand for pesticides in China hasshrunk this year. The resulting fiercer competitionbetween herbicide varieties has ledto a significant price reduction in mostherbicides. The sales and the price of threerice paddy herbicides including butachlor, quinclorac and cinosulfuron have grownhowever. This phenomenon may be closelyrelated to the fact that rice is the most importantgrain crop in China. Rice grows
基金supported by the National Natural Science Foundation of China(32171683)the Shenzhen Science and Technology Program,China(JCYJ20220530145606015)+4 种基金the Agricultural and Social Development Project of Guangzhou Municipal Science and Technology Bureau,China(202206010058)the Special Fund for Agro-scientific Research in the Public Interest of China(201503122)the Natural Science Foundation of Guangdong Province,China(2020A1515010494)the Yangfan Innovative&Entrepreneurial Research Team Project,China(2015YT02H032)the Zhang Hong-da Science Research Fund of Sun Yat-sen University,China。
文摘Winter planting green manures in southern China effectively improve soil properties and rice production through microbial community construction.However,the effects of soil communities of arbuscular mycorrhizal fungi(AMF)from different winter planting green manures on the soil properties and post-cropping rice production remain unclear.In this study,the soil AMF communities of three common winter planting patterns in southern China,winter fallow,winter ryegrass(Lolium multiflorum L.),and winter Chinese milk vetch(Astragalus sinicus L.),were explored and their effects on post-cropping rice production were investigated.Compared with winter fallow,the winter ryegrass and winter Chinese milk vetch patterns could alleviate soil acidification,significantly increase soil AMF spore density,and improve the soil AMF community structure.Based on sterilized soil,rice production indicators such as thousandseed weight,theoretical yield,and the grain amylose and total sugar contents of rice inoculated with AMF spores from winter Chinese milk vetch soil were 6.68–53.57%higher than those without AMF inoculation.Rice panicle weight,seed setting rate,and theoretical yield were 15.38–22.71%higher in the treatment with AMF spores from winter ryegrass soil than in the treatments with no AMF inoculation.In addition,the protein,amylose,and total sugar contents of rice grains were 14.92,104.82,and 802.23 mg kg^(–1),respectively,which were 31.31,14.25 and 34.47%higher than those without AMF inoculation.The AMF community dominated by Glomus and Acaulospora in winter Chinese milk vetch had a more positive effect on the improvement of rice yield,while the AMF community dominated by Glomus in winter ryegrass soil was more conducive to rice quality improvement.These findings have revealed the critical role of AMF communities from green manure in rice production,which lays the theoretical basis for a promising strategy to promote the sustainable development of southern winter agriculture.
基金Supported by the Special Study on Mineral Resources Planning in Changchun City(No.JM-2020-11-13594)Jilin Agricultural Geological Survey Project(No.12120105111208)。
文摘In order to identify the nutrient level and environmental quality of paddy fields in Wanchang area,and to provide scientific basis and technical support for planting rice in Wanchang area, the soil geochemicalsurvey was carried out, 30 samples were collected from paddy soil in Wanchang area, and 20 elements(indicators) were analyzed. The characterization of the elemental content of soils in the study area was carriedout, and the geochemical level for soil nutrients, the geochemical level for the soil environment, and thecomprehensive geochemical level of soil quality were evaluated. The results showed that the average valuesof K content and pH of the soil in the study area were smaller than the background values of Jilin Province,and the average values of 18 elements including N, P, Ca, S, Pb, Zn etc. were bigger than the backgroundvalues of Jilin Province. The results of the evaluation of soil single element nutrient in the study area showedthat the available state nutrient levels of Mn, Zn, Cu, and K increased compared with the total amounts ofnutrients level, with Cu increasing the most;the available state nutrient level of N, P, B, and Mo decreasedcompared with the total amounts of nutrients level, with Mo decreasing the most. The comprehensive levelof soil nutrients geochemistry in paddy fields was mainly Level III (medium), accounting for 53.33%, andthe low abundance level was caused by the lack of P element;the comprehensive level of soil environmentalgeochemistry was mainly Level I (clean), accounting for 96.67%, with only slight pollution caused byCd. The comprehensive geochemical level of soil quality was mainly Level II, accounting for 66.67%.Suggestions were put forward for the rational utilization of soil resources in paddy fields in the study area.
文摘This study aimed to explore the effect of different proportions of organic fertilizer replacing chemical fertilizer on the bacterial community and metabolic function in paddy fields.The 16S rRNA absolute quantitative sequencing method was employed to study the response characteristics of soil bacterial community composition and species absolute abundance to environmental factors under three fertilization treatments[chemical fertilizer(NPK),organic fertilizer replacing 30%of chemical fertilizer(30M,estimated in terms of pure nitrogen,same below),and organic fertilizer replacing 60%of chemical fertilizer(60M)]for two consecutive years.Furthermore,the changes of bacterial metabolic functions of different fertilization treatments were predicted by PICRUSt2.The results showed that replacing chemical fertilizer with organic fertilizer at different proportions significantly increased the total nitrogen(TN),total potassium(TK),hydrolyzable nitrogen(HN),soil organic carbon(SOC),and significantly decreased the soil bulk density(SBD).Moreover,60M demonstrated better performance than 30M.Different fertilization treatments did not cause significant difference in soil bacterial richness index(Chao1)or diversity index(Shannon)but significantly affected bacterial community composition and species abundance.Particularly,60M significantly increased the abundance of 227 species,and it increased the total bacterial abundance by 25.30%and 56.58%compared with NPK and 30M,respectively.Redundancy analysis and Spearman correlation analysis revealed that SOC,TN,and AK were the key factors for shaping specific bacterial community structures under different fertilization treatments.The 60M treatment significantly increased the abundance of bacterial species involved in xenobiotic biodegradation and metabolism,amino acid metabolism,and lipid metabolism,thus improving the metabolic functions of soil microorganisms.
基金supported by grants from the US National Science Foundation(Nos.1911955,2200310)the National Key Research and Development Program of China(No.2023YFF0806900)the China Postdoctoral Science Foundation(Nos.2021TQ0072,2021M700835).
文摘Accurate and timely large-scale paddy rice maps with remote sensing are essential for crop monitoring and management and are used for assessing its impacts on food security,water resource management,and transmission of zoonotic infectious diseases.Optical image-based paddy rice mapping studies employed the unique spectral feature during the flooding/transplanting period of paddy rice.However,the lack of high-quality observations during the flooding/transplanting stage caused by rain and clouds and spectral similarity between paddy rice and natural wetlands often introduce errors in paddy rice identification,especially in paddy rice and wetland coexistent areas.In this study,we used a knowledge-based algorithm and time series observation from optical images(Sentinel-2 and Landsat 7/8)and microwave images(Sentinel-1)to address these issues.The final 10-m paddy rice map had user’s accuracy,producer’s accuracy,F1-score,and overall accuracy of 0.91±0.004,0.74±0.010,0.82,and 0.98±0.001(±value is the standard error),respectively.Over half(62.0%)of the paddy rice pixels had a confidence level of 1(detected by both optical images and microwave images),while 38.0%had a confidence level of 0.5(detected by either optical images or microwave images).The estimated paddy rice area in northeast China for 2020 was 60.83±0.86×10^(3)km^(2).Provincial and municipal rice areas in our data set agreed well with other existing paddy rice data sets and the Agricultural Statistical Yearbooks.These findings indicate that knowledge-based paddy rice mapping algorithms and a combination of optical and microwave images hold great potential for timely and frequently accurate paddy rice mapping in large-scale complex landscapes.
基金supported by the National Natural Science Foundation of China(32372118 and 32188102)the Qian Qian Academician Workstation,China+3 种基金the Specific Research Fund of the Innovation Platform for Academicians of Hainan Province,China(YSPTZX202303)the Nanfan Special Project,Chinese Academy of Agricultural Sciences(ZDXM2315)the Chinese Academy of Agricultural Sciences Talent Plan-Outstanding Young Talentthe Zhejiang Province’s High-level Talent Special Support Plan-Young Talent,China。
文摘In natural ecosystems,the timely abscission of seeds in wild plants is a crucial adaptive trait that contributes to reproductive success,population renewal,and colony expansion(Thurber et al.2010).In contrast,the tendency for high seed shattering in domesticated crops,such as rice,not only reduces paddy yield but also complicates mechanized harvesting.
基金supported by the National Natural Science Foundation of China(Nos.32371734,42007034,41920104008,and U22A20593)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA28020400)+2 种基金the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2023205)the Young Scientist Group Project of Northeast Institute of Geography and Agroecology of China(No.2022QNXZ04)the Science and Technology Development Project of Jilin Province of China(No.YDZJ202101ZYTS006).
文摘The conversion of saline-alkali soils into paddy fields for long-term rice cultivation involves multiple disturbances,and as a result,soil microbial communities are altered to adapt to changing environmental conditions.However,a comprehensive understanding of the succession of soil bacterial communities that occurs during this process is still lacking.In the present study,we utilized data obtained from paddy fields of different rice cultivation years(0-23 years)to investigate the compositional and functional succession of soil bacterial communities.We focused on core bacterial taxa that were specifically enriched at different successional stages.Generalized joint attribute modeling(GJAM)was used to identify core bacterial taxa.Results indicated that the bare saline-alkali soil(0 year,prior to any rice cultivation)shared few core amplicon sequence variants(ASVs)with paddy fields.In the bare saline-alkali soil,Longimicrobiaceae from the phylum Gemmatimonadetes was dominant,while the dominance was subsequently replaced by Burkholderiaceae and Pedosphaeraceae--phyla affiliated with Proteobacteria and Verrucomicrobia--after 5 and 23 years of rice cultivation,respectively.The relative abundances of nitrogen metabolism functions in the core bacterial communities of the bare saline-alkali soil were higher than those at other successional stages,while sulfur metabolism functions exhibited the opposite trend.These indicated that the role of the core bacterial taxa in mediating nutrient cycling also evolved and adapted to changing soil conditions as rice cultivation was established.Redundancy analysis(RDA)indicated that the composition of the core bacterial community in paddy fields with rice cultivation for 0,2 and 4,6,8,10,and 12,and 20 and 23 years were driven by soil nitrate nitrogen content,pH,available phosphorus content,and the ratio of total carbon to total nitrogen,respectively.In summary,the present study provides insights into the succession of soil bacterial communities and core bacterial taxa that occurs during long-term rice cultivation.
基金financially supported by the National Natural Science Foundation of China(32202132,32172229)Young Elite Scientists Sponsorship Program by CAST(2022QNRC001)the Priority Academic Program Development of Jiangsu Higher Educations(PAPD)。
文摘Cadmium ion(Cd^(2+))detection technology plays a prominent role in food safety and human health.Herein,we designed and constructed an 2-aminoethyl dihydrogen phosphate(AEP)@upconversion nanoparticles(UCNPs)fluorescence sensor for quantitative detection of Cd^(2+)in paddy rice based on inner filter effect(IFE)combined with enzyme inhibition mechanism.The AEP modification UCNPs can offer a stable fluorescence donor at 658 nm and be quenched by the oxidized tetramethylbenzidine(oxTMB)catalyzed by horseradish peroxidase(HRP)enzymes.Without addition of Cd^(2+),the fluorescence of AEP@UCNPs fluorescence sensor was weaken due to the IFE between AEP@UCNPs and oxTMB.With addition of Cd^(2+),HRP enzyme activity was inhibited by Cd^(2+),leading to the decreased oxTMB,resulting in the enhance upconversion fluorescence intensity.As a result,the fluorescence intensity signal at 658 nm of the IFE-based AEP@UCNPs fluorescence sensor increased linearly with the increase in Cd^(2+)in a wide range from 0.5μmol/L to 6μmol/L and the limit of detection(LOD)was 24.6 n mol/L.In addition,our proposed IFE-based AEP@UCNPs fluorescence sensor can achieve Cd^(2+)detection in paddy rice in 30 min.
基金supported by the National Key R&D Program of China(Grant No.2022YFE0139400)the National Natural Science Foundation of China(Grant No.31961143016)the Shenzhen Science and Technology Program,China(Grant No.JCYJ20200109150650397).
文摘Zinc(Zn)is an essential micronutrient for both plants and humans.Zn deficiency is common in many paddy fields and reduces yield and grain Zn content(GZC).To accelerate breeding for improved GZC and Zn deficiency tolerance(ZDT)rice varieties,it is important to identify genes regulating Zn homeostasis.In this study,a member of the Ser/Thr protein phosphatase family,LOC_Os07g48840(named as OsGZ7),was found to contributed to ZDT and GZC in rice.The expression of OsGZ7 in roots and shoots was inhibited by Zn deficiency and toxicity,but induced by iron(Fe),manganese(Mn),and copper(Cu)deficiency,as well as chromium toxicity.OsGZ7 localized to the cytoplasm and was expressed in all tissues during the tillering,flowering,and grain-filling stages,particularly in the leaf blade and leaf sheath.At the seedling stage,knockout of OsGZ7 enhanced ZDT and increased Zn accumulation in both roots and shoots.At the maturity stage,knockout of OsGZ7 enhanced GZC,while overexpression of OsGZ7 reduced GZC.RNA-seq analysis suggested that OsGZ7 might regulate Zn homeostasis by affecting metal binding,hormone signal transduction,and oxidoreductase activity.Taken together,our findings indicate that OsGZ7 contributes to ZDT and Zn accumulation in rice.
基金supported by the National Natural Science Foundation of China(Grant No.42177116)complementary fund from the Guizhou Provincial Department of Science and Technology+1 种基金Guizhou Provincial 2021 Science and Technology Subsidies(Grant No.GZ2021SIG)the Chinese Academy of Sciences“Light of West China”Program.
文摘Paddy soil is frequently flooded,which leads to anaerobic decomposition of soil organic matter(SOM)to produce CO_(2) and CH_(4).Currently,there is limited research about the impact of nanoparticles on anaerobic SOM decomposition and CH_(4) production in paddy soil.This study investigates the effects of iron oxide nanoparticles(Fe_(3)O_(4) NPs)and multi-walled carbon nanotubes(MWCNTs)on anaerobic SOM decomposition in two paddy soils.The findings showed that addition of nanoparticles(Fe_(3)O_(4) NPs:0.08%and 0.3%;MWCNTs:0.05%and 0.2%)reduced methane production by 7.48%−31.72%in Guiyang soil and 3.32%−31.24%in Fuyang soil,with decrease in SOM decomposition of 32.19%−47.87%and 19.60%−33.09%,respectively.However,the CH_(4)/TIC(total inorganic carbon)ratio was elevated(by 3.17%to 61.92%)after nanoparticles amendment,suggested that TIC production was more significantly suppressed than CH_(4).The Prolixibacteraceae,which usually involve in organic macromolecule decomposition,decreased in relative abundance with inhibition of CH_(4) production by nanoparticles in both soils,suggesting their sensitivity to nanoparticles.In contrast,the relative abundances of many microbial populations increased with the intensified inhibition of soil mineralization by nanoparticles in both soils.Especially,Sedimentibacter and Melioribacterae increased with inhibition of CH_(4) by nanoparticles,and Clostridiaceae,Minicystis as well as Rhodomicrobium increased with the CH_(4)/TIC ratio in both soils,probably because they might provide substrates for methanogens.These results suggested that nanoparticles not only inhibit the decomposition of SOM but also change the fate of decomposed carbon through modulating microbial populations,leading to a substantial increase in the proportion of CH_(4) produced from SOM decomposition.
