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1.
Nat Commun ; 12(1): 2378, 2021 04 22.
Artículo en Inglés | MEDLINE | ID: mdl-33888716

RESUMEN

Structural variation in plant genomes is a significant driver of phenotypic variability in traits important for the domestication and productivity of crop species. Among these are traits that depend on functional meristems, populations of stem cells maintained by the CLAVATA-WUSCHEL (CLV-WUS) negative feedback-loop that controls the expression of the WUS homeobox transcription factor. WUS function and impact on maize development and yield remain largely unexplored. Here we show that the maize dominant Barren inflorescence3 (Bif3) mutant harbors a tandem duplicated copy of the ZmWUS1 gene, ZmWUS1-B, whose novel promoter enhances transcription in a ring-like pattern. Overexpression of ZmWUS1-B is due to multimerized binding sites for type-B RESPONSE REGULATORs (RRs), key transcription factors in cytokinin signaling. Hypersensitivity to cytokinin causes stem cell overproliferation and major rearrangements of Bif3 inflorescence meristems, leading to the formation of ball-shaped ears and severely affecting productivity. These findings establish ZmWUS1 as an essential meristem size regulator in maize and highlight the striking effect of cis-regulatory variation on a key developmental program.


Asunto(s)
Proteínas de Homeodominio/genética , Inflorescencia/crecimiento & desarrollo , Proteínas de Plantas/genética , Factores de Transcripción/metabolismo , Zea mays/crecimiento & desarrollo , Productos Agrícolas/genética , Productos Agrícolas/crecimiento & desarrollo , Citocininas/metabolismo , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Proteínas de Homeodominio/metabolismo , Inflorescencia/citología , Meristema/crecimiento & desarrollo , Mutagénesis , Mutación , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente , Sitios de Carácter Cuantitativo , RNA-Seq , Transducción de Señal/genética , Células Madre , Factores de Transcripción/genética , Zea mays/genética
2.
J Environ Manage ; 289: 112486, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33831757

RESUMEN

Climate change is a global issue threatening agricultural production and human survival. However, agriculture sector is a major source of global greenhouse gases (GHGs), especially CH4 and N2O. Crop residue returning (RR) is an efficient practice to sequestrate soil carbon and increase crop yields. However, the efficiency of RR to mitigate climate change and maintain food security will be affected by the response of GHG emissions at both per area-scale and per yield-scale. Therefore, a national meta-analysis was conducted using 309 comparisons from 44 publications to assess the responses of GHG emissions to RR in China's croplands. The results indicated that little response of GWP to RR was observed with conditions under lower nitrogen fertilizer input rates (0-120 kg ha-1), mulch retention, returning one time in double cropping systems, returning with half residue, weakly acidic soil (pH 5.5-6.5), initial SOC contents >20 g kg-1, or mean annual precipitation <1000 mm. In order to mitigate climate change and sustain food security, RR combined with paddy-upland rotation, nitrogen fertilizer input rates of 240-360 kg ha-1, and neutral soil (pH 6.5-7.5) could decrease GWP at per unit of crop yield, which ultimately leads to a lower effect on GHGI and a higher crop production efficiency. In-depth studies should be conducted in the future to explore the interactions between various factors influencing GHG emissions under RR conditions. Overall, optimizing the interactions with management and site-specific conditions, potential for regulating GHGs emissions of RR can be enhanced.


Asunto(s)
Gases de Efecto Invernadero , Oryza , Agricultura , China , Productos Agrícolas , Calentamiento Global , Efecto Invernadero , Gases de Efecto Invernadero/análisis , Humanos , Metano/análisis , Óxido Nitroso/análisis , Suelo
3.
Environ Sci Technol ; 55(9): 5782-5790, 2021 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-33848129

RESUMEN

Additional evidence indicates that the nitrate stored in the deep soil profile has an important role in regulating the global nitrogen (N) cycle. This study assessed the effects of land-use changes from croplands to intensive orchards (LUCO) on N surplus, nitrate accumulation in deep soil, and groundwater quality in the kiwifruit belt of the northern slope region of the Qinling Mountains, China. LUCO resulted in comparatively high N surplus in orchards (282 vs 1206 kg ha-1 yr-1, respectively). The average nitrate accumulation within the 0-10 m profiles of orchards was 7113 kg N ha-1, which was equal to approximately the total N surplus of 6 years of the orchards. The total nitrate stock within 0-10 m soil profiles of the kiwifruit belt was 266.5 Gg N, which was 3.5 times higher than the total annual N input. The nitrate concentrations of 97% of groundwater samples exceeded the WHO standard. The LUCO resulted in large nitrate storage in the vadose zone and caused serious contamination of groundwater. Our study highlights that nitrate accumulation in the vadose zone of an intensive land-use system is one of the main fates of surplus N and also a hotspot of nitrate accumulation.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Agricultura , China , Productos Agrícolas , Nitratos/análisis , Contaminantes Químicos del Agua/análisis
4.
J Insect Sci ; 21(2)2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33822127

RESUMEN

Sugarcane spittlebugs are considered important pests in sugarcane crops ranging from the southeastern United States to northern Argentina. To evaluate the effects of climate variables on adult populations of Aeneolamia varia (Fabricius) (Hemiptera: Cercopidae), a 3-yr monitoring study was carried out in sugarcane fields at week-long intervals during the rainy season (May to November 2005-2007). The resulting data were analyzed using the univariate Forest-Genetic method. The best predictive model explained 75.8% variability in physiological damage threshold. It predicted that the main climatic factors influencing the adult population would be, in order of importance, evaporation; evapotranspiration by 0.5; evapotranspiration, cloudiness at 2:00 p.m.; average sunshine and relative humidity at 8:00 a.m. The optimization of the predictive model established that the lower and upper limits of the climatic variables produced a threshold in the population development rate of 184 to 267 adult insects under the agroecological conditions of the study area. These results provide a new perspective on decision-making in the preventive management of A. varia adults in sugarcane crops.


Asunto(s)
Hemípteros/crecimiento & desarrollo , Dinámica Poblacional , Saccharum , Animales , Argentina , Inteligencia Artificial , Clima , Productos Agrícolas , Análisis Factorial , Modelos Estadísticos , Control de Plagas , Sudeste de Estados Unidos
5.
J Insect Sci ; 21(2)2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33822128

RESUMEN

The coffee berry borer (CBB), Hypothenemus hampei Ferrari (Coleoptera: Curculionidae), is the most important coffee pest in most of the coffee growing countries. CBB females leave old dry berries after harvest and search for dry noninfested berries on the plant or on the ground to lay eggs or to use as refuge until new berries are available on the coffee trees in the following season. The CBB infestation level and emergence from berries on the ground or on the plants were evaluated in two fields post-harvest in the Spring in Brazil over two seasons. Twenty infested or noninfested berries in separate cages (250 ml plastic cups) were placed on the plants or on the ground under the tree canopy, in each field. The number of infested berries and CBB females that emerged from the infested berries were recorded weekly. CBB emergence was higher from berries on the ground than those on the coffee trees in both seasons, whereas CBB infestation was higher on coffee berries on the plants than those on the ground in season I. Insolation (hours of sunlight) and temperature were the main covariates that affected emergence and infestation by this insect. The results are discussed for monitoring CBB during the time of dispersal with implications on integrated management of this pest.


Asunto(s)
Coffea , Dinámica Poblacional , Gorgojos/crecimiento & desarrollo , Animales , Clima , Productos Agrícolas , Seguimiento de Parámetros Ecológicos , Análisis Factorial , Control de Plagas , Plantas , Semillas , Luz Solar , Temperatura , Gorgojos/fisiología
6.
J Insect Sci ; 21(2)2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33844017

RESUMEN

The codling moth Cydia pomonella (L.) (Lepidoptera: Tortricidae) is a destructive pest of apple (Malus domestica (Rosales: Rosaceae)), pear (Pyrus spp. (Rosales: Rosaceae)), and other pome tree fruits; outbreaks cause significant ecological and economic losses. In this study, we used CLIMEX model to predict and evaluate the global risk of C. pomonella based on historical climate data (1989-2018) and simulated future climate data (2071-2100) under the RCP4.5 scenarios. Cydia pomonella exhibited a wide distribution under both historical and future climate conditions. Climate change is predicted to expand the northern boundary of the potential distribution from approximately 60°N to 75°N. Temperature was the most dominant factor in climatic suitability for the pest. Combinations of multiple meteorological factors (relative humidity and precipitation) associated with a failure to break diapause in certain regions also affect suitability, particularly in northern South America and central Africa. Irrigation only had a slight impact on species favorability in some areas. The projections established in our study present insight into the global potential suitability of C. pomonella under climate change scenarios by the end of the 21st century. Farmers should be aware of the risk associated with the pest based on the results, which would provide guidance for quarantine agencies and trade negotiators worldwide.


Asunto(s)
Cambio Climático , Modelos Estadísticos , Mariposas Nocturnas , Dinámica Poblacional , Animales , Clima , Productos Agrícolas/economía , Diapausa , Análisis Factorial , Frutas , Calentamiento Global , Malus , Mariposas Nocturnas/crecimiento & desarrollo , Mariposas Nocturnas/fisiología , Control de Plagas , Pyrus , Temperatura , Árboles
7.
Plant Physiol Biochem ; 162: 737-751, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33799185

RESUMEN

Photosynthesis is one of the most fundamental biochemical processes on earth such that it is vital to the existence of most lives on this planet. In fact, unravelling the potentials in enhancing photosynthetic efficiency and electron transfer process, which are thought to improve plant growth is one of the emerging approaches in tackling modern agricultural shortcomings. In light of this, zero-dimensional carbon quantum dots (CQD) have emerged and garnered much interest in recent years which can enhance photosynthesis by modulating the associated electron transfer process. In this work, CQD was extracted from empty fruit bunch (EFB) biochar using a green acid-free microwave method. The resulting CQD was characterized using HRTEM, PL, UV-Vis and XPS. Typical rice (C3) and corn (C4) crops were selected in the present study in order to compare the significant effect of CQD on the two different photosynthetic pathways of crops. CQD was first introduced into crop via foliar spraying application instead of localised placement of CQD before seedling development. The influence of CQD on the photosynthetic efficiency of rice (C3) and corn (C4) leaves was determined by measuring both carbon dioxide conversion and the stomatal conductance of the leaf. As a result, the introduction of CQD greatly enhanced the photosynthesis in CQD-exposed crops. This is the first study focusing on phylogenetically constrained differences in photosynthetic responses between C3 and C4 crops upon CQD exposure, which gives a better insight into the understanding of photosynthesis process and shows considerable promise in nanomaterial research for sustainable agriculture practices.


Asunto(s)
Oryza , Puntos Cuánticos , Dióxido de Carbono , Productos Agrícolas , Fotosíntesis , Hojas de la Planta , Zea mays
8.
Int J Mol Sci ; 22(6)2021 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-33809189

RESUMEN

Plant specialized metabolites (SMs) play an important role in the interaction with the environment and are part of the plant defense response. These natural products are volatile, semi-volatile and non-volatile compounds produced from common building blocks deriving from primary metabolic pathways and rapidly evolved to allow a better adaptation of plants to environmental cues. Specialized metabolites include terpenes, flavonoids, alkaloids, glucosinolates, tannins, resins, etc. that can be used as phytochemicals, food additives, flavoring agents and pharmaceutical compounds. This review will be focused on Mediterranean crop plants as a source of SMs, with a special attention on the strategies that can be used to modulate their production, including abiotic stresses, interaction with beneficial soil microorganisms and novel genetic approaches.


Asunto(s)
Productos Biológicos/metabolismo , Productos Agrícolas/metabolismo , Resistencia a la Enfermedad/genética , Metabolismo Secundario/genética , Productos Agrícolas/crecimiento & desarrollo , Flavonoides/metabolismo , Humanos , Región Mediterránea , Redes y Vías Metabólicas/genética , Fitoquímicos/metabolismo , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Estrés Fisiológico/efectos de los fármacos , Terpenos/metabolismo
9.
Int J Mol Sci ; 22(5)2021 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-33807862

RESUMEN

Chitosan-based edible coatings represent an eco-friendly and biologically safe preservative tool to reduce qualitative decay of fresh and ready-to-eat fruits during post-harvest life due to their lack of toxicity, biodegradability, film-forming properties, and antimicrobial actions. Chitosan-based coatings modulate or control oxidative stress maintaining in different manner the appropriate balance of reactive oxygen species (ROS) in fruit cells, by the interplay of pathways and enzymes involved in ROS production and the scavenging mechanisms which essentially constitute the basic ROS cycle. This review is carried out with the aim to provide comprehensive and updated over-view of the state of the art related to the effects of chitosan-based edible coatings on anti-oxidant systems, enzymatic and non-enzymatic, evaluating the induced oxidative damages during storage in whole and ready-to-eat fruits. All these aspects are broadly reviewed in this review, with particular emphasis on the literature published during the last five years.


Asunto(s)
Antioxidantes/química , Quitosano/química , Productos Agrícolas , Películas Comestibles , Conservación de Alimentos , Conservantes de Alimentos/química , Frutas
10.
Pestic Biochem Physiol ; 174: 104826, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33838719

RESUMEN

Liriomyza trifolii is an invasive leafminer fly that inflicts damage on many horticultural and vegetable crops. In this study, the effects of elevated temperatures on L. trifolii tolerance to insecticides abamectin (AB), monosultap (MO) and a mixture of abamectin and monosultap (AM) were firstly investigated, then five CYP450 genes (LtCYPs) were cloned, and expression patterns and NADPH cytochrome C reductase (NCR) activity in L. trifolii were compared in response to high temperature stress and insecticide exposure. Results showed elevated temperatures induced expression of LtCYP450s, the expression level of LtCYP4g1, LtCYP4g15 and LtCYP301A1 after exposed to different high temperature were significantly up-regulated compared with the control (25 °C), while there was no significant difference in LtCYP4E21 and LtCYP18A1. Under the joint high temperature and insecticide stress, the expression of LtCYP4g15, LtCYP18A1 and LtCYP301A1 was significantly higher under elevated temperatures than that of only under AB exposure. For MO and AM exposure, only 40 °C could induce the expression of LtCYP4g15, LtCYP18A1 and LtCYP301A1. In general, the LtCYPs expression pattern was correlated with increased NCR activity and decreased mortality in response to insecticide exposure under elevated temperatures. These all demonstrated that insecticide tolerance in L. trifolii could be mediated by high temperature. This study improves our understanding of L. trifolii physiology and offers a theoretical context for improved control that ultimately reduces the abuse of insecticides and decreases exposure to non-target organisms.


Asunto(s)
Dípteros , Insecticidas , Animales , Productos Agrícolas , Sistema Enzimático del Citocromo P-450/genética , Insecticidas/toxicidad , Temperatura
11.
Molecules ; 26(6)2021 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-33803724

RESUMEN

Drought poses a serious threat to oilseed crops by lowering yield and crop failures under prolonged spells. A multi-year field investigation was conducted to enhance the drought tolerance in four genotypes of Camelina and canola by selenium (Se) application. The principal aim of the research was to optimize the crop yield by eliciting the physio-biochemical attributes by alleviating the adverse effects of drought stress. Both crops were cultivated under control (normal irrigation) and drought stress (skipping irrigation at stages i.e., vegetative and reproductive) conditions. Four different treatments of Se viz., seed priming with Se (75 µM), foliar application of Se (7.06 µM), foliar application of Se + Seed priming with Se (7.06 µM and 75 µM, respectively) and control (without Se), were implemented at the vegetative and reproductive stages of both crops. Sodium selenite (Na2SeO3), an inorganic compound was used as Se sources for both seed priming and foliar application. Data regarding physiochemical, antioxidants, and yield components were recorded as response variables at crop maturity. Results indicated that WP, OP, TP, proline, TSS, TFAA, TPr, TS, total chlorophyll contents, osmoprotectant (GB, anthocyanin, TPC, and flavonoids), antioxidants (APX, SOD, POD, and CAT), and yield components (number of branches per plant, thousand seed weight, seed, and biological yields were significantly improved by foliar Se + priming Se in both crops under drought stress. Moreover, this treatment was also helpful in boosting yield attributes under irrigated (non-stress) conditions. Camelina genotypes responded better to Se application as seed priming and foliar spray than canola for both years. It has concluded that Se application (either foliar or priming) can potentially alleviate adverse effects of drought stress in camelina and canola by eliciting various physio-biochemicals attributes under drought stress. Furthermore, Se application was also helpful for crop health under irrigated condition.


Asunto(s)
Brassica napus/efectos de los fármacos , Brassica napus/crecimiento & desarrollo , Brassicaceae/efectos de los fármacos , Brassicaceae/crecimiento & desarrollo , Sequías , Selenio/administración & dosificación , Antioxidantes/análisis , Brassica napus/fisiología , Brassicaceae/fisiología , Productos Agrícolas/efectos de los fármacos , Productos Agrícolas/crecimiento & desarrollo , Productos Agrícolas/fisiología , Osmorregulación , Pakistán , Aceites Vegetales/aislamiento & purificación , Proteínas de Plantas/análisis , Aceite de Brassica napus/aislamiento & purificación
12.
J Zhejiang Univ Sci B ; 22(4): 253-284, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33835761

RESUMEN

Since it was first recognized in bacteria and archaea as a mechanism for innate viral immunity in the early 2010s, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) has rapidly been developed into a robust, multifunctional genome editing tool with many uses. Following the discovery of the initial CRISPR/Cas-based system, the technology has been advanced to facilitate a multitude of different functions. These include development as a base editor, prime editor, epigenetic editor, and CRISPR interference (CRISPRi) and CRISPR activator (CRISPRa) gene regulators. It can also be used for chromatin and RNA targeting and imaging. Its applications have proved revolutionary across numerous biological fields, especially in biomedical and agricultural improvement. As a diagnostic tool, CRISPR has been developed to aid the detection and screening of both human and plant diseases, and has even been applied during the current coronavirus disease 2019 (COVID-19) pandemic. CRISPR/Cas is also being trialed as a new form of gene therapy for treating various human diseases, including cancers, and has aided drug development. In terms of agricultural breeding, precise targeting of biological pathways via CRISPR/Cas has been key to regulating molecular biosynthesis and allowing modification of proteins, starch, oil, and other functional components for crop improvement. Adding to this, CRISPR/Cas has been shown capable of significantly enhancing both plant tolerance to environmental stresses and overall crop yield via the targeting of various agronomically important gene regulators. Looking to the future, increasing the efficiency and precision of CRISPR/Cas delivery systems and limiting off-target activity are two major challenges for wider application of the technology. This review provides an in-depth overview of current CRISPR development, including the advantages and disadvantages of the technology, recent applications, and future considerations.


Asunto(s)
Sistemas CRISPR-Cas , Edición Génica/métodos , Terapia Genética , Fitomejoramiento , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Productos Agrícolas/genética , Humanos , Premio Nobel
13.
Science ; 372(6537): 81-84, 2021 04 02.
Artículo en Inglés | MEDLINE | ID: mdl-33795455

RESUMEN

Pesticide impacts are usually discussed in the context of applied amounts while disregarding the large but environmentally relevant variations in substance-specific toxicity. Here, we systemically interpret changes in the use of 381 pesticides over 25 years by considering 1591 substance-specific acute toxicity threshold values for eight nontarget species groups. We find that the toxicity of applied insecticides to aquatic invertebrates and pollinators has increased considerably-in sharp contrast to the applied amount-and that this increase has been driven by highly toxic pyrethroids and neonicotinoids, respectively. We also report increasing applied toxicity to aquatic invertebrates and pollinators in genetically modified (GM) corn and to terrestrial plants in herbicide-tolerant soybeans since approximately 2010. Our results challenge the claims of a decrease in the environmental impacts of pesticide use.


Asunto(s)
Organismos Acuáticos/efectos de los fármacos , Productos Agrícolas , Invertebrados/efectos de los fármacos , Plaguicidas/toxicidad , Plantas Modificadas Genéticamente , Plantas/efectos de los fármacos , Animales , Herbicidas/toxicidad , Insecticidas/toxicidad , Neonicotinoides/toxicidad , Piretrinas/toxicidad , Soja , Zea mays
14.
Int J Mol Sci ; 22(6)2021 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-33808829

RESUMEN

To date, soil salinity becomes a huge obstacle for food production worldwide since salt stress is one of the major factors limiting agricultural productivity. It is estimated that a significant loss of crops (20-50%) would be due to drought and salinity. To embark upon this harsh situation, numerous strategies such as plant breeding, plant genetic engineering, and a large variety of agricultural practices including the applications of plant growth-promoting rhizobacteria (PGPR) and seed biopriming technique have been developed to improve plant defense system against salt stress, resulting in higher crop yields to meet human's increasing food demand in the future. In the present review, we update and discuss the advantageous roles of beneficial PGPR as green bioinoculants in mitigating the burden of high saline conditions on morphological parameters and on physio-biochemical attributes of plant crops via diverse mechanisms. In addition, the applications of PGPR as a useful tool in seed biopriming technique are also updated and discussed since this approach exhibits promising potentials in improving seed vigor, rapid seed germination, and seedling growth uniformity. Furthermore, the controversial findings regarding the fluctuation of antioxidants and osmolytes in PGPR-treated plants are also pointed out and discussed.


Asunto(s)
Desarrollo de la Planta , Fenómenos Fisiológicos de las Plantas , Rhizobiaceae/fisiología , Salinidad , Estrés Salino , Tolerancia a la Sal , Productos Agrícolas , Variación Genética , Genómica/métodos , Fotosíntesis , Proteómica/métodos , Plantones/fisiología , Simbiosis
15.
Ying Yong Sheng Tai Xue Bao ; 32(3): 1112-1118, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33754579

RESUMEN

Cotton is one of the most important crops in the world. With the increasing scarce of global water resources, irrigation water will become a major limiting factor in cotton production. Deficit irrigation is an irrigation method which consumes less water than the normal evapotranspiration of crops. It is an effective water-saving method due to improved water use efficiency without sacrificing cotton yield and fiber quality. We summarized the effects of deficit irrigation on the growth and water use efficiency of cotton. The results showed that deficit irrigation promoted the transformation from vegetative growth to reproductive growth, reduced plant height, leaf area, and total biomass of cotton, and subsequently improved the harvest index, stem diameter and water use efficiency. Finally, based on the current research and combined with cotton production reality, the application and future development of deficit irrigation were proposed, which might provide theoretical guidance for the sustainable development of cotton plantation in arid areas.


Asunto(s)
Riego Agrícola , Agua , Biomasa , Productos Agrícolas , Hojas de la Planta
16.
Food Chem ; 354: 129552, 2021 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-33756332

RESUMEN

Pesticide residues are one of the most important issues affecting food safety. In this review, the general situation of pesticide residues in fruits and vegetables based on the background of the Chinese fruit and vegetable industry is first described. On the basis of primary processing of agricultural products, the effects of processing methods on the removal and metabolism of pesticide residues are reviewed in this paper. In addition, the transformation mechanism of pesticides in crops and in the environment is discussed. Finally, this study summarizes the development trend of pesticide-residue monitoring methods. With the prohibition of a large number of pesticides in China, the risk of pesticide residues is gradually reduced. However, some highly toxic pesticides can still be detected. Furthermore, the development of high-resolution mass spectrometry screening methods and rapid and intelligent detection instruments is the development trend for pesticide monitoring in the future.


Asunto(s)
Contaminación de Alimentos/análisis , Manipulación de Alimentos , Residuos de Plaguicidas/análisis , Residuos de Plaguicidas/aislamiento & purificación , China , Productos Agrícolas/química , Frutas/química , Humanos , Verduras/química
17.
Environ Sci Technol ; 55(8): 4679-4687, 2021 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-33749272

RESUMEN

Neonicotinoids from insecticidal seed coatings can contaminate soil in treated fields and adjacent areas, posing a potential risk to nontarget organisms and ecological function. To determine if cover crops can mitigate neonicotinoid contamination in treated and adjacent areas, we measured neonicotinoid concentrations for three years in no-till corn-soybean rotations, planted with or without neonicotinoid seed coatings, and with or without small grain cover crops. Although neonicotinoids were detected in cover crops, high early season dissipation provided little opportunity for winter-planted cover crops to absorb significant neonicotinoid residues; small grain cover crops failed to mitigated neonicotinoid contamination in either treated or untreated plots. As the majority of neonicotinoids from seed coatings dissipated shortly after planting, residues did not accumulate in soil, but persisted at concentrations below 5 ppb. Persistent residues could be attributed to historic neonicotinoid use and recent, nearby neonicotinoid use. Tracking neonicotinoid concentrations over time revealed a large amount of local interplot movement of neonicotinoids; in untreated plots, contamination was higher when plots were less isolated from treated plots.


Asunto(s)
Productos Agrícolas , Insecticidas , Insecticidas/análisis , Neonicotinoides , Semillas/química , Suelo
18.
Ecotoxicol Environ Saf ; 215: 112102, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33721664

RESUMEN

Agricultural soils derived from black shale are typically enriched in potentially toxic metals. This is a serious problem, both in terms of the ecological environment and human health. To assess the levels of potentially toxic metals, 90 paired soil-crops samples were collected from the Anji Country, western Zhejiang province, a typical exposed black shale area in China. Concentrations and bioavailability of potentially toxic metals in the soil-crops system were measured, and the associated potential risks were further evaluated. Results showed the enrichment of potentially toxic metals (i.e. Cd, Pb, Cu, Zn and Ni) in the soil and crop samples, especially a significant accumulation of Cd. Sequential extraction data indicated that Cd in soils derived from black shale was the second most dominant element in the exchangeable fraction (mean at 33.42%) and possessed high bioavailability, whereas Pb was mostly retained in the residual fraction (mean at 76.34%) and exhibited low mobility. The total concentration as well as mobility and bioavailability of Cd were the highest in the sampled soils. This resulted in a high potential ecological risk in areas with agricultural soils derived from black shale, which could eventually jeopardize the health of local residents through various exposure pathways. Overall, our findings provide a scientific basis for developing suitable management strategies to mitigate the exposure to potentially toxic metals in high risk areas.


Asunto(s)
Monitoreo del Ambiente , Metales Pesados/análisis , Contaminantes del Suelo/análisis , Afroamericanos , Agricultura , Disponibilidad Biológica , China , Productos Agrícolas/metabolismo , Humanos , Minerales/metabolismo , Medición de Riesgo , Suelo
19.
Environ Pollut ; 278: 116832, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33725536

RESUMEN

To evaluate pesticide regulatory standards in agricultural crops, we introduced a regulatory modeling framework that can flexibly evaluate a population's aggregate exposure risk via maximum residue levels (MRLs) under good agricultural practice (GAP). Based on the structure of the aggregate exposure model and the nature of variable distributions, we optimized the framework to achieve a simplified mathematical expression based on lognormal variables including the lognormal sum approximation and lognormal product theorem. The proposed model was validated using Monte Carlo simulation, which demonstrates a good match for both head and tail ends of the distribution (e.g., the maximum error = 2.01% at the 99th percentile). In comparison with the point estimate approach (i.e., theoretical maximum daily intake, TMDI), the proposed model produced higher simulated daily intake (SDI) values based on empirical and precautionary assumptions. For example, the values at the 75th percentile of the SDI distributions simulated from the European Union (EU) MRLs of 13 common pesticides in 12 common crops were equal to the estimated TMDI values, and the SDI values at the 99th percentile were over 1.6-times the corresponding TMDI values. Furthermore, the model was refined by incorporating the lognormal distributions of biometric variables (i.e., food intake rate, processing factor, and body weight) and varying the unit-to-unit variability factor (VF) of the pesticide residues in crops. This ensures that our proposed model is flexible across a broad spectrum of pesticide residues. Overall, our results show that the SDI is significantly reduced, which may better reflect reality. In addition, using a point estimate or lognormal PF distribution is effective as risk assessments typically focus on the upper end of the distribution.


Asunto(s)
Residuos de Plaguicidas , Plaguicidas , Agricultura , Productos Agrícolas , Contaminación de Alimentos/análisis , Residuos de Plaguicidas/análisis , Plaguicidas/análisis
20.
Ecotoxicol Environ Saf ; 215: 112103, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33740485

RESUMEN

The Mediterranean is a region of substantial agriculture production that faces concurrent environmental stresses and freshwater pollution given the occurrence of emerging contaminants (ECs). Among these pollutants, the surface-active substances have been suggested to enhance the bioavailability of other ECs. This research evaluates a comparative uptake and translocation assessment of irrigation exposure to atenolol (ATN, 60 µg/L), carbamazepine (CBZ, 60 µg/L) and triclosan (TCS, 30 µg/L) alone vs. these combined with perfluorooctanesulfonic acid (PFOS, 10 µg/L) under semifield (i.e., soil experimental set) vs. hydroponics (i.e., soilless experimental set) growing conditions with lettuce, radish and tomato plants. Both experimental sets revealed efficient root uptake and translocation for the three ECs regardless of their co-existence with PFOS. The overall results of the uptake and translocation of the ECs in the lettuce and tomato plants suggested a simultaneous treatment-plant organ interaction, which was not affected by PFOS being present in both experimental sets. PFOS in irrigation water did not increase cellular perviousness to the other three ECs. These observations support the hypothesis of factors other than PFOS being responsible for the differential bioaccumulation and translocation potentials seen in both experimental sets. However, the radish plants co-irrigated with PFOS brought about increased movement of ECs from roots to aerial parts, more specifically ATN and CBZ in the soil experimental set, and ATN and TCS in the soilless set. These results support the notion that factors inherent to the physiological characteristics of this root vegetable contributed to ECs' increased tendency to move from roots to aerial parts. Despite the three ECs efficiently accumulating, the risk to humans from eating the edible parts of these plants grown under soil or soilless conditions was low.


Asunto(s)
Ácidos Alcanesulfónicos , Productos Agrícolas , Fluorocarburos , Contaminantes del Suelo/análisis , Carbamazepina , Agua Dulce , Humanos , Hidroponia , Lechuga , Raphanus , Suelo , Triclosán/análisis , Verduras
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