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1.
Nature ; 579(7799): 350-351, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32188945
2.
Environ Monit Assess ; 192(4): 210, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32128628

RESUMO

Stored grain pests cause great damage to various grain products, and protection against these pests is currently based on synthetic insecticides and fumigants. As a result, these chemicals cause problems, including grain contamination with chemical residues and the development of resistance by insect pests to these chemicals. Therefore, to combat this issue, in the present study, an enhanced form of diatomaceous earth (DE), Grain-Guard, and Metarhizium anisopliae (Metschnikoff) Sorokin (Ascomycota: Sordariomycetes) were evaluated alone and in combination against adults of Liposcelis paeta (Pearman) (Psocoptera: Liposcelididae), Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae), Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), and Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). M. anisopliae was used at a rate of 1.7 × 104 conidia kg-1 grain alone as well as with two doses of DE (25 and 50 ppm) on wheat under different exposure time courses (4, 7, and 14 days). It is worth mentioning that the combination of M. anisopliae and DE was highly effective against the adults of L. paeta, C. ferrugineus, R. dominica, and T. castaneum after 14 days of exposure. When DE and M. anisopliae were applied alone, DE showed more effectiveness than fungal conidia. Progeny emergence was decreased when modified DE was applied at a high dose rate with the fungus and suppressed at a low dose. The cadavers of all species in the trials showed a maximum percentage of mycosis, and sporulation (conidia/ml) also showed the same result when the fungus was tested alone, while low mycosis and sporulation were achieved under the application of a mixture with a high dose of modified DE. Our findings indicate the best possible combination of DE (at low dose rates) along with a fungus that might contribute to lowering health and environmental risks.


Assuntos
Besouros , Terra de Diatomáceas , Controle de Insetos , Inseticidas , Metarhizium , Animais , Grão Comestível , Monitoramento Ambiental , Controle de Insetos/métodos
3.
Chemosphere ; 244: 125548, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32050343

RESUMO

Wheat (Triticum aestivum L.) cultivation in cadmium (Cd) polluted soil is a core concern to food quality and food security all over the world. Cadmium toxicity is mainly associated with a Cd influx from contaminated soils to human via grain consumption. Organic amendments are widely used for Cd immobilization and enhancement in plant growth, but the residual effects of these amendments are mostly unknown. The present study addressed the long-term effects of organic amendments in contaminated soils by evaluating their residual effects on 3rd crop (wheat) in the sequence. Initially six organic amendments viz. rice husk biochar (RHB), wheat-straw biochar (WSB), cotton-stick biochar (CSB), poultry manure (PM), press mud (PrMd) and farm manure (FM) were applied once at a rate of 2% in Cd (50 mg kg-1) contaminated soil with wheat-rice rotation. After the harvest of wheat and rice crops, wheat (Var. Galaxy) was again grown in the same pots. Results revealed that plants grown under Cd stress (without any amendment) contain more tissue (root, shoot and grain) and soil AB-DTPA extractable Cd. The soil amended with RHB has shown lowest AB-DTPA extractable Cd (69% lower than control). Similarly, RHB application has significantly reduced wheat root, shoot and grain Cd concentrations compared to control and other amendments. Results have confirmed the effectiveness of RHB residual contents as an active amendment for restriction of Cd in non-bioavailable pool of soil and better growth and yield of wheat.


Assuntos
Cádmio/metabolismo , Poluentes do Solo/metabolismo , Triticum/metabolismo , Disponibilidade Biológica , Cádmio/análise , Carvão Vegetal , Produtos Agrícolas , Grão Comestível/química , Esterco , Oryza/crescimento & desenvolvimento , Solo , Poluentes do Solo/análise , Triticum/crescimento & desenvolvimento
4.
Sci Total Environ ; 711: 135183, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32000350

RESUMO

China is the largest rice producer and consumer in the world. Accurate estimations of paddy rice planting area and rice grain production is important for feeding the increasing population in China. However, Southern China had substantial losses in paddy rice area over the last three decades in those regions where paddy rice has traditionally been produced. Several studies have shown increased paddy rice area in Northeast China. Here we document the annual dynamics of paddy rice area, gross primary production (GPP), and grain production in Northeast China (Heilongjiang, Jilin and Liaoning provinces) during 2000-2017 using agricultural statistical data, satellite images, and model simulations. Annual maps derived from satellite images show that paddy rice area in Northeast China has increased by 3.68 million ha from 2000 to 2017, which is more than the total combined paddy rice area of North Korea, South Korea, and Japan. Approximately 82% of paddy rice pixels had an increase in annual GPP during 2000-2017. The expansion of paddy rice area slowed down substantially since 2015. Annual GPP from those paddy rice fields cultivated continuously over the 18 years were moderately higher than that from other paddy rice fields, which suggested that improved management practices could increase grain production in the region. There was a strong linear relationship between annual GPP and annual rice grain production in Northeast China by province and year, which illustrates the potential of using satellite-based data-driven model to track and assess grain production of paddy rice in the region. Northeast China is clearly an emerging rice production base and plays an increasing role in crop production and food security in China. However, many challenges for the further expansion and sustainable cultivation of paddy rice in Northeast China remain.


Assuntos
Oryza , Agricultura , China , Grão Comestível , Japão , República da Coreia
5.
Waste Manag ; 105: 240-247, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32088570

RESUMO

This paper deals with the investigation of ultrasound (US) pretreatment of brewer's spent grain (BSG) as a means of releasing fermentable sugars, and the subsequent production of ethanol from this lignocellulosic biomass. Using response surface methodology (RSM), the influence of US power, time, temperature and biomass loading on fermentable sugar yield from BSG was studied. The optimal conditions were found to be 20% US power, 60 min, 26.3 °C, and 17.3% w/v of biomass in water. Under these conditions, an approximate 2.1-fold increase in reducing sugar yield (325 ± 6 mg/g of biomass) was achieved, relative to untreated BSG (151.1 ± 10 mg/g of biomass). In contrast to acid or alkaline pretreatment approaches, the use of water obviated the need for neutralization for the recovery of sugars. The characterization of native and pretreated BSG was performed by HPLC, FTIR, SEM and DSC. Fermentation studies using S. cerevisiae growing on pretreated BSG resulted in a conversion of 66% of the total sugar content ininto ethanol with an ethanol content of 17.73 ± 2 g/ 100 g of pretreated BSG. These results suggest that ultrasound pretreatment is a promising technology for increased valorization of BSG as a feedstock for production of bioethanol, and points ton the need for further work in this area.


Assuntos
Saccharomyces cerevisiae , Sonicação , Biomassa , Grão Comestível , Fermentação
6.
J Environ Manage ; 260: 109576, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32046879

RESUMO

Agroecology has been suggested as a promising concept for reconciling agricultural production and environmental sustainability by optimizing ecological processes that deliver ecosystem services (ES) to replace external inputs. While this statement is widely agreed upon, few assessments of real-life conditions exist that assess multiple ES simultaneously. This paper provides an assessment of seven ES based on 14 indicators in three agroecological farming systems (AFS) and thirteen of their adjacent conventional farming systems (CFS). Based on field-scale measurements spread over three years, our findings suggest that the studied AFS succeed in providing a wider array of regulating services than their neighboring CFS. Soil aggregate stability and soil respiration rates are in general more supported in AFS, which also show lower pest abundance. On the other hand, CFS show higher grain production and higher performance for two out of three fodder quality indices. While this 'productivity gap' may be due to the still-evolving state of the studied AFS, we nuance this through the lens of an emerging paradigm to assess farming system multi-performance. It is now argued that we need to shift from a volume-focused production system to a system that also values the ecological processes underpinning crop production and other benefits to society. Based on our findings, we recommend future work to iterate our initiative, including several indicators per service and embed these into a wider context of co-adaptive science-practice to further develop context-specific and user-useful research.


Assuntos
Agricultura , Ecossistema , Conservação dos Recursos Naturais , Produção Agrícola , Grão Comestível , Fazendas
7.
Adv Neurobiol ; 24: 377-394, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32006365

RESUMO

The grain group is small, hard, dry seeds, known to be more durable than other staple foods. They have been a part of the human diet for tens of thousands of years. The two foremost types of commercial grain crops are cereals and legumes or pulses, discussed in Chapter 13 "Seeds." A low intake of whole grains is actually the leading dietary risk factor for death and disease in the USA. Few healthy grains are discussed in this chapter that can help prevent health problems like heart diseases, diabetes, and cancers.


Assuntos
Grão Comestível/química , Grão Comestível/classificação , Valor Nutritivo , /estatística & dados numéricos , Fibras na Dieta/análise , Doença , Humanos , Fatores de Risco , Estados Unidos/epidemiologia
8.
Chemosphere ; 242: 125247, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31896173

RESUMO

Wood vinegar (WV) was applied alone or combined with biochar (BC) to observe their efficiency on suppressing the ammonia (NH3) volatilization from rice paddy soil. Five treatments, i.e., control (240 kg N ha-1 applied in urea), WV-5 and WV-10 (240 kg N ha-1 plus 5 and 10 t WV ha-1, respectively), and their counterparts WV-5-BC and WV-10-BC (WV-5 and WV-10 plus 7 t BC ha-1), were evaluated by a soil columns experiment. The N fertilizer was split applied as basal and two supplementary fertilizations (named BF, SF1 and SF2, respectively). The results showed that WV-5 treatment increased rice grain yield up to 11.2% compared to the control. Compared with the control, four WV-amended treatments, exhibited lower pH values of the floodwater (7.94-8.18 vs 8.47 and 7.85-7.91 vs 7.98) and the topsoil (6.52-6.76 vs 6.82 and 6.82-6.92 vs 6.99) during the BF and SF1 periods. Both WV-5 and WV-10 increased the NH4+-N contents of topsoil by 10.9-17.8% and 16.1-36.2% after BF and SF1, respectively, than control treatment. Additionally, the floodwater of the WV-amended treatments had higher NH4+-N concentration than control during the first three days after N fertilization, which can be attributed to the stimulating effect of WV on soil urease enzyme activity. WV did not effectively reduce NH3 volatilization as hypothesized. Interestingly, four WV-amended had relatively reduced the yield-scale NH3 volatilization by 13.6% than the control. It is suggested that WV needs to be applied with BC at a moderate rate to achieve optimum rice yield and mitigate NH3 volatilization.


Assuntos
Ácido Acético , Amônia/análise , Carvão Vegetal/química , Metanol , Amônia/química , Grão Comestível/química , Fertilizantes/análise , Nitrogênio/análise , Oryza/química , Solo/química , Ureia/química , Volatilização
9.
Eur J Histochem ; 64(1)2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31941265

RESUMO

The seed morphology of three Pseudocereal Grains (PSCg), i.e. quinoa (Chenopodium quinoa Willd, Chenopodiaceae), buckwheat (Fagopyrum esculentum Moench, Polygonaceae) and amaranth (Amaranthus caudatus L., Amaranthaceae) was studied by light microscopy (LM) and Environmental Scanning Electron Microscopy coupled with Energy Dispersive Spectroscopy (ESEM-EDS). LM was used with visible light to evaluate either unstained sections or sections stained with Azan mixture and with fluorescent light. The aim of the study was to compare the architecture of the three seeds in order to connect their morphology with nutrient localization. The Azan staining allowed for the visualization of the seed coat, the embryo - with its shoot apical meristem - and the radicle cell layers, whereas the use of fluorescent microscopy identified the cells rich in phenolic compounds. Finally, the ESEM-EDS analysis revealed that the seed coat of the quinoa was thinner than that of amaranth or buckwheat. In all PSCg, starch granules appeared to be located in large polygonal cells, surrounded by a thin cell wall. Several globoids of proteins were observed in the embryo cells. In the radicle section, the vascular bundles of the procambium were evident, while Amaranth only showed a consistent layer of calcium crystals, located between the embryo and the perysperm. The morphological differences of the three PSCg were discussed in the context of their structural resistance to processing technologies which impact on nutritional value of derived foods.


Assuntos
Amaranthus/anatomia & histologia , Chenopodium quinoa/anatomia & histologia , Grão Comestível/anatomia & histologia , Fagopyrum/anatomia & histologia , Sementes/anatomia & histologia , Amaranthus/embriologia , Chenopodium quinoa/embriologia , Grão Comestível/embriologia , Fagopyrum/embriologia , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência , Sementes/embriologia
10.
Sci Total Environ ; 713: 136665, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-31955111

RESUMO

Arsenic (As) and cadmium (Cd) typically exhibit divergent fates in soil, which complicates efforts to decrease As and Cd accumulation in the edible parts of crops. Here, we performed pot experiments to examine the effect of sulfate application on As and Cd accumulation in the grain of wheat grown in contaminated soil. Compared to the control (no sodium sulfate addition), application of 120 mg kg-1 sodium sulfate decreased the rhizosphere soil pH from 7.27 to 7.10 and increased the soil extractable Cd concentration; however, it did not significantly influence the soil extractable As concentration. However, sodium sulfate addition decreased As and Cd concentrations in wheat grain, in association with decreased As and Cd translocation from root and straw to grain, rather than from soil to root. Furthermore, sodium sulfate addition significantly decreased membrane lipid peroxidation and enhanced photosynthesis, while increasing the uptake of nitrogen, phosphorus, and sulfur. These effects increased the growth and grain weight of plants grown in As and Cd co-contaminated soil. Our findings provide insight into the mechanisms by which sulfate modulates As and Cd uptake and translocation in wheat; moreover, our findings will enable formulation of strategies to decrease As and Cd concentrations in the grain of wheat grown in As and Cd co-contaminated soil.


Assuntos
Triticum , Arsênico , Cádmio , Grão Comestível , Solo , Poluentes do Solo , Sulfatos
11.
Trends Plant Sci ; 25(3): 226-235, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31954615

RESUMO

Nitrogen-fixing microbial associations with cereals have been of intense interest for more than a century (Roesch et al., Plant Soil 2008;302:91-104; Triplett, Plant Soil 1996;186:29-38; Mus et al., Appl. Environ. Microbiol. 2016;82:3698-3710; Beatty and Good, Science 2011;333:416-417). A recent report demonstrated that an indigenous Sierra Mixe maize landrace, characterized by an extensive development of aerial roots that secrete large amounts of mucilage, can acquire 28-82% of its nitrogen from atmospheric dinitrogen (Van Deynze et al., PLoS Biol. 2018;16:e2006352). Although the Sierra Mixe maize landrace is unique in the large quantity of mucilage produced, other cereal crops secrete mucilage from underground and aerial roots and we hypothesize that this may represent a general mechanism for cereals to support associations with microbial diazotrophs. We propose a model for the association of nitrogen-fixing microbes with maize mucilage and identify the four main functionalities for such a productive diazotrophic association.


Assuntos
Grão Comestível , Fixação de Nitrogênio , Animais , Produtos Agrícolas , Camundongos , Nitrogênio , Raízes de Plantas , Zea mays
12.
Trends Plant Sci ; 25(3): 279-290, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31956036

RESUMO

Expansion of the human population demands a significant increase in cereal production. The main component of cereal grains is endosperm, a body of starchy endosperm (SE) cells surrounded by aleurone (AL) cells with transfer cells (TC) at the base and embryo surrounding (ESR) cells adjacent to the embryo. The data reviewed here emphasize the modular nature of endosperm by first suggesting that sucrose promotes development of the fertilized triploid endosperm cell. Next, that the basal syncytial endosperm responds to glucose by turning on TC development. The default endosperm cell fate is SE and ESR differentiation is likely activated by signaling from the embryo. Cells on the exterior surface of the endosperm are specified as AL cells.


Assuntos
Grão Comestível , Endosperma , Diferenciação Celular , Transdução de Sinais , Amido
13.
Ying Yong Sheng Tai Xue Bao ; 31(1): 148-156, 2020 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-31957391

RESUMO

Field experiment was conducted to examine the effects of combined application of N and Zn fertilizers on translocation, distribution, and accumulation of Zn in different organs in wheat plants. The results showed that Zn concentration and Zn accumulation in each organ were significantly different under different treatments. Compared with N3 (120 kg·hm-2), the grain Zn concentration of N1 (240 kg·hm-2) and N2 (180 kg·hm-2) increased 22.0% and 8.9%, respectively. Compared with the non-Zn application treatment (CK), grain Zn concentration under ZnS (soil Zn fertilization), ZnF (foliar Zn fertilization), and ZnS+ZnF (soil Zn fertilization combined with foliar Zn fertilization) treatments were increased by 5.4%, 60.5% and 72.8%, while Zn accumulation in grain were increased by 21.3% 82.5% and 102.4%, respectively. Zn in grain mainly came from the remobilization of Zn uptaken after antheis, with the accumulative contribution being 89.9% and 100.0% in ZnF and ZnS+ZnF, respectively. Compared with ZnS, Zn fertilizer recovery and use efficiency of ZnF and ZnS+ZnF were increased by 4.8, 1.1 times and 7.9, 2.2 times, respectively. Under current condition, Zn concentration and Zn accumulation in different organs of wheat increased with increasing N rate when it was less than 240 kg·hm-2, which was significantly increased in the grain by foliar Zn application. Therefore, Zn concentration and Zn accumulation in wheat grain could be increased by maintaining the high-yield N fertilization and combining the foliar Zn application in the late growth stage, which would improve Zn nutritional quality of wheat grain.


Assuntos
Triticum , Zinco , Grão Comestível , Fertilizantes , Nitrogênio , Solo
14.
Ying Yong Sheng Tai Xue Bao ; 31(1): 165-172, 2020 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-31957393

RESUMO

The unreasonable resource allocation and lower resource use efficiency for rice-wheat double cropping system in Jianghuai region resulted from climate change severely limit the coordinated development of annually high yield and high efficiency crops. Optimizing seasonal resource allocation through sowing date adjustment is an important way to tap the annual high-yield potential and improve resource use efficiency. To quantify the effects of sowing date of rice and wheat on annual yield and resource allocation and utilization efficiency, field experiments were conducted in 2013-2015. Results showed that compared with the conventional rice-wheat cropping system (T2), the two seasons appropriate late-cast cropping system (T3) could coordinate resource allocation in the two seasons through the sowing date adjustment, and transfer the redundant radiation and heat resources in the wheat season to the rice. The distribution rate of accumulated temperature, radiation and rainfall resources for T3 were: rice season accounted for 60.5%, 46.5% and 56.7%, wheat season accounted for 36.3%, 50.0% and 40.9%, and the ratio between two seasons was 1.67, 0.94 and 1.39, respectively. Rice yield and its proportion of annual production were significantly increased. The wheat yield was significantly decreased, with the variation range being smaller than that of rice. The total annual yield was increased by 336.3 kg·hm-2 as compared with T2. The temperature, radiation and rainfall production efficiency for rice in T3 were increased by 9.8%, 5.6% and 8.3% in compared to T2, respectively. There was no significant difference in the climate resource utilization efficiency of wheat season. The annual resource production efficiency of T3 was increased by 4.8%, 3.1% and 6.0% over the T2, respectively. Earlier (T1) or latest sowing (T4) of two seasons cropping system was not appropriate for annual yield formation and resource utilization. In summary, improving resource utilization efficiency in rice season is the key way to increase annual grain yield potential in Jianghuai region. The results provided theoretical and practical bases for the excavation of yield potential of the regional annual cropping system and the adjustment of planting structure.


Assuntos
Oryza , Triticum , Agricultura , Produtos Agrícolas , Grão Comestível , Estações do Ano
15.
Food Chem ; 312: 125829, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31901703

RESUMO

Free and bound phenolics were extracted from the fibre fraction of wholemeal (W) wheat and barley (B) cookies which had been fortified with 15% blackcurrant powder. Blackcurrant enriched cookies contained between 55 and 66 % higher total phenolics respectively compared control cookies. Ferulic acid in wheat and barley cookie extracts, and quercetin and kaempferol-3-glucoside in wheat cookies with 15% blackcurrant were the dominant phenolic acids. Cellular antioxidant activity was higher in samples with blackcurrant inclusion when evaluated in a cancer cell HepG2 model. Inhibition of cell proliferation was lower for the phenolic samples from cookies with blackcurrant addition. These samples suppressed the regulation of inflammatory cytokine IL-1ß (about 3 to 4-fold), IL-6 (about 2-fold) and transcription signalling factor NF-kB (about 2-fold) and showed an up-regulation of the satiety gene NUCB-2/nesfatin-1 (about 4-fold) in compared with control samples.


Assuntos
Fibras na Dieta/metabolismo , Regulação da Expressão Gênica , Ribes/genética , Antioxidantes/análise , Grão Comestível/química , Hordeum/química , Humanos , Fenóis/análise , Triticum/química
16.
Chemosphere ; 242: 125289, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31896204

RESUMO

Selenium (Se) and zinc (Zn) are essential microelements for humans with crucial biological functions. In this study, we determined Se and Zn concentrations in soils and rice grains on Hainan Island and investigated how their spatial distributions are related to soil mineral elements, topography, and vegetation coverage. Overall, the concentrations of Se and Zn in soils were higher than the background values for Chinese soil; the Se concentrations in rice grains were higher than the threshold value for Se deficiency in grains, but Zn concentrations were lower than the proposed critical concentration. Both Spearman's correlation and stepwise regression analysis showed that the concentrations of soil Fe and Ca significantly affected soil Se and Zn: a difference of 1 g kg-1 in soil Fe changed soil Se by 2.820 µg kg-1 and soil Zn by 0.785 mg kg-1, respectively, while a difference of 1 g kg-1 in soil Ca changed soil Se by 3.249 µg kg-1 and soil Zn by 0.356 mg kg-1, respectively. For rice grains, Se and Zn concentrations decreased with increasing elevation; every 100 m increase in elevation could decrease Se by 0.022 mg kg-1 and Zn by 0.912 mg kg-1. Moreover, the impact of Fe and Ca on soil Zn was relatively strong in the northeast region, while the influence of elevation on rice grain Se was more significant in the central region. The findings contribute to a better understanding of factors driving the distribution of Se and Zn in soils and crops.


Assuntos
Grão Comestível/química , Monitoramento Ambiental/métodos , Oryza/química , Selênio/análise , Solo/química , Zinco/análise , Altitude , Cálcio/análise , China , Humanos , Ferro/análise , Ilhas , Análise de Regressão , Análise Espacial
17.
Food Chem ; 312: 126077, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31891885

RESUMO

Polyphenols from five pigmented sorghum (PS) flours were in vitro evaluated as possible modulators of starch digestibility. White sorghum (WS) flour was used as control. Untargeted metabolomics depicted the phenolic composition of raw and cooked flours (obtained through heating at 100 °C for 30 min in water) highlighting differences in flavonoids and phenolic acids. Raw PS flours were characterized by greater tannin and kafirin contents when compared to WS, and, after cooking, PS flours had greater resistant starch (from 4.2 to 21.4 g /100 g dry matter), and lower starch hydrolysis index (HI) with respect to cooked WS. Multivariate statistics showed that flavonoids characterizing PS were the most discriminant compounds during the in vitro digestion. In addition, kafirin and total tannins content (on raw ingredients) along with the anthocyanin profiles (on cooked samples) were negative correlated with HI. Therefore, PS flours might be good candidates for the formulation of functional foods.


Assuntos
Polifenóis/química , Sorghum/química , Amido/química , Culinária , Grão Comestível/química , Grão Comestível/metabolismo , Farinha/análise , Hidrólise , Metabolômica , Polifenóis/metabolismo , Sorghum/metabolismo , Amido/metabolismo , Taninos
18.
Chemosphere ; 241: 125106, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31683428

RESUMO

A pot experiment was conducted to investigate the possible mediatory effect of organic amendments (vermicompost and biochar) and selenium (Se) on Cd bioaccumulation in both rice cultivars (high-Cd accumulation rice: Yuzhenxiang (YZX) and low-Cd accumulation rice: Changliangyou772 (CLY)) in high-Cd-contaminated soils. The results showed that Cd sensitivity and tolerance were cultivar-dependent, and grain Cd contents for CLY accorded with the Chinese national food safety standards (0.2 mg kg-1), whereas grain Cd levels for YZX were 1.4-5.8 times higher than those for CLY. Soil applications of amendments decreased grain Cd levels by 3.5%-36.9% for YZX and 36.1%-74.4% for CLY. Moreover, vermicompost (VC) was more effective in reducing Cd bioaccumulation than biochar (BC). A combination of Se and organic amendments could significantly increase grain Se contents and help further reduce grain Cd levels by 5.8%-20.8%, compared to the single organic amendments. This mitigation progress could be attributed to the changes of Cd translocation and distribution among rice tissues and the inhibition of Cd bioavailability in soil through the alteration in soil properties. Organic amendments, especially high dose (5%), increased soil pH and organic matter contents, and correspondingly decreased soil Cd bioavailability. A sequential extraction analysis suggested that organic amendments and Se facilitated the transformation of soil Cd from the bioavailable form to the immobilized Cd form, and thus decreased grain Cd levels. Hence, co-applications of organic amendments and Se in combination with low-Cd accumulation cultivar could be an effective strategy for both Se needs of humans and safe utilization of Cd polluted soil.


Assuntos
Cádmio/farmacocinética , Carvão Vegetal/farmacologia , Compostagem , Oryza/metabolismo , Selênio/farmacologia , Disponibilidade Biológica , Cádmio/análise , Grão Comestível/química , Exposição Ambiental/normas , Humanos , Oryza/química , Selênio/análise , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/farmacocinética , Especificidade da Espécie
19.
Chemosphere ; 242: 125136, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31654806

RESUMO

Large areas of paddy fields in southern China have been contaminated by arsenic (As), which causes serious problems such as the reduction of grain yield and high As concentrations in brown rice. To test the possibility of using plant growth-promoting rhizobacteria (PGPR) to promote rice growth and decrease As accumulation in brown rice in such paddy fields, three As-resistant PGPRs (strains S6, S7 and S10) were isolated and incorporated into two rice cultivars (Zhendao 14 and Jianyou G2) grown in different environments. The results showed that all PGPRs promoted rice growth (grain yield increased by 10.50-51.30% under greenhouse conditions and by 4.83-9.16% in paddy fields) and reduced As damage in rice. Specifically, S10 decreased As accumulation in brown rice in both greenhouse (3.50-26.01%) and paddy-field conditions (9.26-10.50%) by significantly reducing the available As concentration in rhizospheric soil, especially in the Dabaoshan-B field (34.00%). Conversely, in greenhouse condition, strains S6 and S7 increased As concentrations by 6.10-20.10% and 2.14-14.60%, respectively. Our results suggested that PGPR inoculation could be used to decrease As accumulation and promote rice growth in As-contaminated paddy fields. However, as the effects of PGPRs differed by strain and depended on environmental factors, careful selection of the strains and environmental conditions, and pre-testing, will be essential before applying PGPRs to As-contaminated paddy fields.


Assuntos
Arsênico/análise , Oryza/química , Rhizobiaceae/fisiologia , Poluentes do Solo/análise , Arsênico/metabolismo , China , Grão Comestível/química , Oryza/crescimento & desenvolvimento , Oryza/microbiologia , Desenvolvimento Vegetal , Solo , Poluentes do Solo/metabolismo
20.
Chemosphere ; 242: 125128, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31678846

RESUMO

Many reports suggest that exogenous Si addition could reduce Cd translocation to aerial part and make grain safe for rice production. But it remains unclear whether its supplementation during different growth phases can differentially impact Cd uptake in rice. Here, Positive effects of Si applied at different growth phases on biomass and yield of rice were observed. Dry weight of shoot including stem, leaf and grain was enhanced significantly by 15% when Si added at transplanting stage. Grain-yields supplied with Si at transplanting, jointing and heading stages were increased obviously by 14%, 11% and 12%, respectively. Higher percentage of filled spikelet and lower unfilled spikelet number per panicle were found when Si supplied at jointing stage. The increases of Cd accumulation in rice plants by Si application were mainly manifested in roots. Compared to CK, Cd accumulation in root when Si applied at transplanting and tillering stages were elevated by 75% and 64%, respectively. While Cd accumulation in aboveground tissues were all declined by Si addition. Bioconcentration and translocation factors were decreased significantly when Si added at jointing stage. In addition, higher soil pH, lowest available Cd-concentration in soil and Cd2+ concentration in xylem sap at 15d after flowering were found when the Si was applied at jointing stage. Overall, Si application at transplanting would be more beneficial to the growth of rice and increased Cd content in root, while Si supplied at jointing would be more favorable for grain filling and reducing Cd accumulation in shoot.


Assuntos
Cádmio/metabolismo , Oryza/metabolismo , Silício , Poluentes do Solo/metabolismo , Biomassa , Cádmio/análise , Grão Comestível/química , Poluição Ambiental , Oryza/química , Folhas de Planta/química , Solo/química , Poluentes do Solo/análise
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