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Selenium (Se) reduces Sclerotinia stem rot disease incidence of oilseed rape by increasing plant Se concentration and shifting soil microbial community and functional profiles
2019
Liu, Kang | Cai, Miaomiao | Hu, Chengxiao | Sun, Xuecheng | Cheng, Qin | Jia, Wei | Yang, Tao | Nie, Min | Zhao, Xiaohu
Sclerotinia stem rot (SSR), a soil-borne plant disease, cause the yield loss of oilseed rape. Selenium (Se), a beneficial element of plant, improves plant resistance to pathogens, and regulates microbial communities in soil. Soil microbial communities has been identified to play an important role in plant health. We studied whether the changes in soil microbiome under influence of Se associated with oilseed rape health. SSR disease incidence of oilseed rape and soil biochemical properties were investigated in Enshi district, “The World Capital of Selenium”, and soil bacterial and fungal communities were analyzed by 16S rRNA and ITS sequencing, respectively. Results showed that Se had a strong effect on SSR incidence, and disease incidence inversely related with plant Se concentration. Besides, soil Se enhanced the microbiome diversities and the relative abundance of PGPR (plant growth promoting rhizobacteria), such as Bryobacter, Nitrospirae, Rhizobiales, Xanthobacteraceae, Nitrosomonadaceae and Basidiomycota. Furthermore, Soil Se decreased the relative abundance of pathogenic fungi, such as Olpidium, Armillaria, Coniosporium, Microbotryomycetes and Chytridiomycetes. Additionally, Se increased nitrogen metabolism, carbohydrate metabolism and cell processes related functional profiles in soil. The enrichment of Se in plants and improvement of soil microbial community were related to increased plant resistance to pathogen infection. These findings suggested that Se has potential to be developed as an ecological fungicide for biological control of SSR.
اظهر المزيد [+] اقل [-]Combination of compositional data analysis and machine learning approaches to identify sources and geochemical associations of potentially toxic elements in soil and assess the associated human health risk in a mining city
2020
Tepanosyan, Gevorg | Sahakyan, Lilitʻ | Maghakyan, Nairuhi | Saghatelyan, Armen
Mining activities change the chemical composition of the environment and have negative reflection on people’s health and there is no single measure to deal with adverse consequences of mining activities, as each case is specific and needs to be understood and mitigated in a unique way. In this study, the combination of compositional data analysis (CoDA), k-means algorithm, hierarchical cluster analysis applied to reveal the geochemical associations of potentially toxic elements (PTE) in soil of Alaverdi city (Armenia) (Ti, Fe, Ba, Mn, Co, V, Pb, Zn, Cu, Cr, Mo, As). Additionally, to assess PTE-induced health risk, two commonly used approaches were used. The obtained results show that the combination of CoDA and machine learning algorithms allow to identify and describe three geochemical associations of the studied elements: the natural, manmade and hybrid. Moreover, the revealed geochemical associations were linked to the natural pattern of distribution of the element concentrations including the influence of the natural mineralization of the parent rocks, as well as the emission from the copper smelter and urban management related activities. The health risk assessment using the US EPA method demonstrated that the observed contents of studied elements are posing a non-carcinogenic risk to children in the entire territory of the city. In the case of adults, the non-carcinogenic risk was identified in areas situated close to the copper smelter. The Summary pollution index (Zc) values were in line with the results of the US EPA method and indicated that the main residential part of the city was under the hazardous pollution level suggesting the possibility of increase in the overall incidence of diseases among frequently ill individuals, children with chronic diseases and functional disorders of vascular system. The obtained results indicated the need for further in-depth studies with special focus on the synergic effect of PTE.
اظهر المزيد [+] اقل [-]Combined effects of elevated CO2 and natural climatic variation on leaf spot diseases of redbud and sweetgum trees
2010
McElrone, Andrew J. | Hamilton, Jason G. | Krafnick, Anthony J. | Aldea, Mihai | Knepp, Rachel G. | DeLucia, Evan H.
Atmospheric CO2 concentrations are predicted to double within the next century and alter climate regimes, yet the extent that these changes will affect plant diseases remains unclear. In this study conducted over five years, we assessed how elevated CO2 and interannual climatic variability affect Cercospora leaf spot diseases of two deciduous trees. Climatic data varied considerably between the five years and altered disease expression. Disease incidence and severity for both species were greater in years with above average rainfall. In years with above average temperatures, disease incidence for Liquidambar styraciflua was decreased significantly. When significant changes did occur, disease incidence and severity always increased under elevated CO2. Chlorophyll fluorescence imaging of leaves revealed that any visible increase in disease severity induced by elevated CO2 was mitigated by higher photosynthetic efficiency in the remaining undamaged leaf tissue and in a halo surrounding lesions. Climatic variation had a greater impact than elevated CO2 on Cercospora diseases, especially since leaf photosynthetic efficiency increased under elevated CO2.
اظهر المزيد [+] اقل [-]Spatial and temporal analysis of the COVID-19 incidence pattern in Iran
2021
Hazbavi, Zeinab | Mostfazadeh, Raoof | Alaei, Nazila | Azizi, Elham
In the present paper, province-level variations of novel coronavirus (COVID-19) disease incidence across Iran were investigated. To this end, a geo-database from infected cases, deaths, total population, death-to-population ratio, and infected case-to-death ratio for 31 provinces of Iran and during seven successive periods of February 18–March 19 (P1), March 20–April 8 (P2), April 9–April 28 (P3), April 29–May 20 (P4), May 21–June 20 (P5), June 21–September 21 (P6), and September 22–October 21 (P7) of 2020 was built. Based on the last reports of the population and housing census (2018), Iran is home to 81.8 million people. Nationwide case series of 536,181 and 29,403 infected cases and deaths respectively with COVID-19 were reported to Iran’s Minister of Health from February 18 to October 21, 2020. Of the infected cases, 5.48% have died. The spatiotemporal patterns of COVID-19 were different throughout the 31 study provinces. Firstly, the central, north, and northwest of Iran were the main hosts of this virus. Shortly after, other parts of Iran, most notably the west and southwest regions, experienced a momentous rise in the numeral of infected cases and deaths. In the first study period, Tehran, West Azerbaijan, Mazandaran, Qom, and Gilan had the most infected cases (> 1000). In the second to fourth periods, the number of provinces with higher than 1000 infected cases, respectively, reached 12, 10, and 17. For the last three periods (P5–P7), 31 provinces were assigned higher than 1000 infected cases. Tehran had the most deaths with an increasing trend for all study periods among other provinces. The areas around Kohgiluyeh and Boyer-Ahmad, Bushehr, Chaharmahal and Bakhtiari, South Khorasan, and Ilam had the least death cases. The numbers of infected (death) cases in Iran for the first to seventh periods (P1–P7) respectively were 16,730 (1208), 41,285 (1595), 28,530 (1876), 16,366 (1856), 80,694 (6588), 201,585 (6232), and 128,336 (6953). The location quotient (LQ) index showed that most provinces of Iran have the LQ > 1 indicating a high degree of COVID-19 concentration in most of the province’s area in comparison with the nation, especially in the last study period (P7).
اظهر المزيد [+] اقل [-]Domestic Rainwater Harvesting: Microbial and Chemical Water Quality and Point-of-Use Treatment Systems
2013
de Kwaadsteniet, M. | Dobrowsky, P. H. | van Deventer, A. | Khan, W. | Cloete, T. E.
Quality of the essential commodity, water, is being compromised by contaminants originating from anthropogenic sources, industrial activities, agriculture, etc. Water scarcity and severe droughts in many regions of the world also represent a significant challenge to availability of this resource. Domestic rainwater harvesting, which involves collection and storage of water from rooftops and diverse surfaces, is successfully implemented worldwide as a sustainable water supplement. This review focuses on chemical and microbial qualities of domestic rainwater harvesting, with a particular focus on sources of chemical pollution and major pathogens associated with the water source. Incidences of disease linked to consumption and utilization of harvested rainwater are also discussed. In addition, various procedures and methods used for disinfection and treatment of harvested rainwater, such as implementation of filter systems (activated carbon, slow sand filtration, etc.), heat treatment, and chlorination, among others, are also presented.
اظهر المزيد [+] اقل [-]Effects of agricultural pesticides on the health of Rana pipiens frogs sampled from the field
2013
Christin, M. S. | Ménard, L. | Giroux, I. | Marcogliese, D. J. | Ruby, S. | Cyr, D. | Fournier, M. | Brousseau, P.
There is evidence that over the last 30 years, there have been mass declines in diverse geographic locations among amphibian populations due to disease outbreaks. Multiple causes have been suggested to explain this increase in disease incidence. Among these, climate changes, environmental pollution and reduced water quality are gaining attention. Indeed, some chemicals of environmental concerns are known to alter the immune system. It is possible that exposure to these pollutants could alter the immune system of anurans and render them more susceptible to different pathogens. In this study, we sampled Rana pipiens in five different sites near St. Lawrence River (Quebec, Canada) during the months of July and September in 2001. Two of these sites were protected areas, in which low levels of pesticides were detected, while the remaining three sites were located in areas with intensive corn and soybeans cultivations. Our results demonstrated that frogs living in agricultural regions are smaller in size and weight than frogs living in areas with lower levels of pesticides at both sampling times. Moreover, we have observed a significant decrease in the number of splenocytes (cellularity) and the phagocytic activity in frogs sampled in impacted sites. Taken together, these results suggest that frogs living in agricultural regions might be more vulnerable to infections and diseases through their smaller size and alteration of their immune system. Our results also contribute to the overall discussion on factors involved in amphibian declines.
اظهر المزيد [+] اقل [-]Effects of exogenous salicylic acid and pH on pathogenicity of biotrophy-associated secreted protein 1 (BAS1)-overexpressing strain, Magnaporthe oryzae
2019
Yang, Jing | Wang, Yunfeng | Liu, Lin | Liu, Lina | Wang, Chunmei | Wang, Changmi | Li, Chengyun
Abiotic stress can influence the interactions between a pathogen and its host. In this paper, we analyzed the effects of salicylic acid (SA) and pH on the morphological development and pathogenicity of Magnaporthe oryzae, the pathogen that causes rice (Oryza sativa) blast. A strain of rice blast that overexpresses biotrophy-associated secreted protein 1 (BAS1) and a wild-type (WT) strain were pretreated with different levels of pH and different concentrations of SA to analyze M. oryzae colony growth, sporulation, spore germination, dry weight of hypha, and appressorium formation. Disease incidence and the expression of defense-related genes in infected rice were analyzed after pretreatment with pH 5.00 or pH 8.00 and 200 μM SA. The results showed that both SA and pH had some influence on morphological development, including sporulation and appressorium formation of the BAS1-overexpression strain. In the 200 μM SA pretreatment, there was a lower incidence of disease and higher expression levels of the rice defense-related genes PR1a, PAL, HSP90, and PR5 on leaves inoculated with the BAS1-overexpession strain compared with the WT strain, whereas, LOX2 appeared to be downregulated in the BAS1-overexpession strain compared with the WT. In both pH treatments, disease incidence and expression of HSP90 were higher and the expression of PR1a and PR10a and LOX2 and PAL was lower in leaves inoculated with the BAS1-overexpression strain compared with leaves inoculated with the WT strain. We conclude that SA and pH affect morphological development of the BAS1-overexpression blast strain, but that these factors have little influence on the pathogenicity of the strain, indicating that BAS1-overexpression may have enhanced the tolerance of this rice blast strain to abiotic stressors. This work suggests new molecular mechanisms that exogenous SA and pH affect the interactions between M. oryzae and rice.
اظهر المزيد [+] اقل [-]The relationship between extreme temperature and emergency incidences: a time series analysis in Shenzhen, China
2018
Guo, Yinsheng | Ma, Yue | Ji, Jiajia | Liu, Ning | Zhou, Guohong | Fang, Daokui | Huang, Guangwen | Lan, Tao | Peng, Chaoqiong | Yu, Shuyuan
Extreme temperature has been reported to be associated with an increase in acute disease incidence in several cities. However, few similar studies were carried out in Shenzhen, which is a subtropical city located in the southern China. This study explored the relationship between the emergency incidences and extreme temperatures, and investigated the role of air pollutants played in the temperature-related effects on human health in Shenzhen. We conducted a distributed lag nonlinear model study on the effect of extreme temperatures on emergency incidences in Shenzhen city during 2013–2017. Here, only the total emergency incidences, emergency incidences for respiratory diseases, and cardiovascular diseases were taken into consideration. Air pollution, subgroups, and seasons were adjusted to investigate the impacts of extreme temperatures on emergency incidences. Relative risk (RR) and 95% confidence intervals were calculated with the R software. From lag 0 to 21 days, the RR of temperature-total emergency department visits, temperature-cardiovascular, and temperature-respiratory diseases was 1.09 (95% CI: 0.98–1.20), 1.22 (95% CI: 0.96–1.56), and 1.06 (95% CI: 0.70–1.60) at extremely low temperature (first percent of temperature, 10 °C), respectively. During the same lag days, the RR was 1.02 (95 % CI: 0.92–1.14), 0.64 (95% CI: 0.49–0.86), and 0.92 (95% CI: 0.56–1.53) between extremely high temperature and total emergency department visits, cardiovascular, and respiratory diseases, respectively. The cumulative effects gradually went up with time for all types of emergency incidences in warm seasons (5 days moving average of temperature < 22 °C). However, the cumulative effects of total emergency incidences and Cvd emergency incidences were increased within the first lag 5 days, and then decreased until lag 21 in hot seasons (5 days moving average of temperature ≥ 22 °C). The cumulative effects of Res emergency incidences showed a declined trend from lag 0 to lag 21. The elderly (≥ 65, P1: RR = 1.49, 95% CI (1.30, 1.71); P99: RR = 0.86, 95% CI (0.71, 1.04)) and men (P1: RR = 1.27, 95% CI (1.14, 1.42)) seemed to be more vulnerable to extreme temperature than the younger (≤ 64, P1: RR = 1.19, 95% CI (1.08, 1.32); P99: RR = 1.00, 95% CI (0.89, 1.12)) and women (P1: RR = 1.17, 95%CI (1.06, 1.30)). The effects of extremely low temperature on all types of emergency incidences were stronger than those of extremely high temperature in the whole year. In addition, impacts of cold weather lasted about several days while those of hot weather were acute and rapid. An increased frequency of emergency incidences is predicted by rising temperatures variations. These results have clinical and public health implications for the management of emergency incidences.
اظهر المزيد [+] اقل [-]Air pollution from industrial waste gas emissions is associated with cancer incidences in Shanghai, China
2018
Cong, Xiaowei
Outdoor air pollution may be associated with cancer risk at different sites. This study sought to investigate outdoor air pollution from waste gas emission effects on multiple cancer incidences in a retrospective population-based study in Shanghai, China. Trends in cancer incidence for males and females and trends in waste gas emissions for the total waste gas, industrial waste gas, other waste gas, SO₂, and soot were investigated between 1983 and 2010 in Shanghai, China. Regression models after adjusting for confounding variables were constructed to estimate associations between waste gas emissions and multiple cancer incidences in the whole group and stratified by sex, Engel coefficient, life expectancy, and number of doctors per 10,000 populations to further explore whether changes of waste gas emissions were associated with multiple cancer incidences. More than 550,000 new cancer patients were enrolled and reviewed. Upward trends in multiple cancer incidences for males and females and in waste gas emissions were observed from 1983 to 2010 in Shanghai, China. Waste gas emissions came mainly from industrial waste gas. Waste gas emissions was significantly positively associated with cancer incidence of salivary gland, small intestine, colorectal, anus, gallbladder, thoracic organs, connective and soft tissue, prostate, kidney, bladder, thyroid, non-Hodgkin’s lymphoma, lymphatic leukemia, myeloid leukemia, and other unspecified sites (all p < 0.05). Negative association between waste gas emissions and the esophagus cancer incidence was observed (p < 0.05). The results of the whole group were basically consistent with the results of the stratified analysis. The results from this retrospective population-based study suggest ambient air pollution from waste gas emissions was associated with multiple cancer incidences.
اظهر المزيد [+] اقل [-]Effect of vermicast generated from an allelopathic weed lantana (Lantana camara) on seed germination, plant growth, and yield of cluster bean (Cyamopsis tetragonoloba)
2014
Karthikeyan, M. | Hussain, N. | Gajalakshmi, S. | Abbasi, S.A.
In perhaps the first-ever study of its kind, the effect of vermicompost, derived solely from an allelopathic weed, on the germination, growth, and yield of a botanical species, has been carried out. In test plots, the soil was treated with the vermicompost of lantana (Lantana camara) at the rates of 5, 7.5, and 10 t ha⁻¹, and cluster bean (Cyamopsis tetragonoloba) was grown on it. The performance of these systems was compared with the systems in which the soil was fortified with inorganic fertilizers (IFs) in concentrations equivalent to those present in the respective vermicompost (VC) treatments. Additionally, a set of control was studied in which the soil was used without fortification by either VC or IF. It was seen that up to 51.5 % greater germination success occurred in the VC treatments compared to controls. VC also supported better plant growth in terms of stem diameter, shoot length, shoot mass, number of leaves, and leaf pigments. The positive impact extended up to fruit yield. In addition, vermicast application enhanced root nodule formation, reduced disease incidence, and allowed for a smaller number of stunted plants. The results indicate that allelopathic ingredients of lantana seem to have been totally eliminated during the course of its vermicomposting and that lantana vermicompost has the potential to support germination, growth, and fruit yield better than equivalent quantities of IFs.
اظهر المزيد [+] اقل [-]