Use of functional genomics to assess the climate change impact on Aspergillus flavus and aflatoxin production

2016 ◽  
Vol 9 (5) ◽  
pp. 665-672 ◽  
Author(s):  
M.K. Gilbert ◽  
B.M. Mack ◽  
G.A. Payne ◽  
D. Bhatnagar
Keyword(s):  
Climate Change ◽  
Functional Genomics ◽  
Aspergillus Flavus ◽  
Pathogenic Fungus ◽  
Regulatory Gene ◽  
Aflatoxin Production ◽  
Toxin Production ◽  
Transcriptomic Response ◽  
Climate Conditions ◽  
Change Impact

Aspergillus flavus is an opportunistic and pathogenic fungus that infects several crops of agricultural importance and under certain conditions may produce carcinogenic mycotoxins. Rising global temperatures, disrupted precipitation patterns and increased CO2 levels that are associated with future climate conditions are expected to impact the growth and toxigenic potential of A. flavus. Both laboratory and real world observations have demonstrated this potential, especially when examining the effects of water availability and temperature. Recent experiments have also established that CO2 may also be affecting toxin production. The application of current technologies in the field of functional genomics, including genomic sequencing, RNA-seq, microarray technologies and proteomics have revealed climate change-related, abiotic regulation of the aflatoxin cluster and influence on the plant-fungus interaction. Furthermore, elevated CO2 levels have been shown to impact expression of the aflatoxin biosynthetic regulatory gene aflR. The use of functional genomics will allow researchers to better understand the underlying transcriptomic response within the fungus to climate change, with a view towards predicting changes in fungal infection and toxin production associated with climate change.

scholarly journals Investigation of Climate and Land Use Change Impacts on Stream Flow of Guder Catchment, Ethiopia

2021 ◽  
Author(s):  
Bekam Bekele Gulti ◽  
Boja Mokonnen Manyazew ◽  
Abdulkerim Bedewi Serur
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Stream Flow ◽  
Open Space ◽  
Smart Growth ◽  
Assessment Model ◽  
Study Region ◽  
Climate Conditions ◽  
Change Impact ◽  
The Impact

Abstract Climate change (CC) and land use/cover change (LUCC) are the main drivers of streamflow change. In this paper, we investigate the impact of climate and LULC change impact on stream flow of Guder catchment by using Soil and Water Assessment model (SWAT). The scenarios were designed in a way that LULC was changed while climate conditions remain constant; LULC was then held constant under a changing climate and combined effect of both. The result shows that, the combined impacts of climate change and LULC dynamics can be rather different from the effects that follow-on from LULC or climate change alone. Streamflow would be more sensitive to climate change than to the LULC changes scenario, even though changes in LULC have far-reaching influences on streamflow in the study region. A comprehensive strategy of low impact developments, smart growth, and open space is critical to handle future changes to streamflow systems.

scholarly journals Climate change impact – residential unit

2019 ◽  
Vol 279 ◽  
pp. 03007
Author(s):  
Ján Hollý ◽  
Adela Palková
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Weather Data ◽  
Emission Scenarios ◽  
Climate Data ◽  
Climate Conditions ◽  
Residential Unit ◽  
Data Application ◽  
Change Impact ◽  
Selection Of

The issue of climate change is undeniably demonstrating its presence. Consequently, there is a rising need to be prepared for upcoming threats by any means possible. One of the precautions includes obtaining the information characterizing the expected impact of global warming. This will allow authorities and other stakeholders to act accordingly in time. The article presents the assessment of the extent of impact of energy-related construction solutions in dwelling type unit situated in Central Europe region under the 21st century climate conditions. The findings represent eventual demands of energy for cooling and heating and its prospective savings. This is conducted by consecutively and automatically changing the parameters in individual simulation runs. As a basis for simulations, regionally scaled weather data of three different climate areas are used. These data are based on the emission scenarios by IPCC and are reaching to the year 2100. The selection of assessed parameters and climate data application are briefly explained in the article. The results of simulations are evaluated and recommended solutions are stated in regard to the specific energy-related construction changes. The aim is to successfully mitigate and adapt to the climate change phenomenon.

scholarly journals Is bias correction of Regional Climate Model (RCM) simulations possible for non-stationary conditions?

2012 ◽  
Vol 9 (11) ◽  
pp. 12765-12795 ◽  
Author(s):  
C. Teutschbein ◽  
J. Seibert
Keyword(s):  
Climate Change ◽  
Bias Correction ◽  
Climate Change Impact ◽  
Climate Model ◽  
Regional Climate ◽  
Climate Conditions ◽  
Impact Studies ◽  
Split Sample ◽  
Sample Test ◽  
Change Impact

Abstract. In hydrological climate-change impact studies, Regional Climate Models (RCMs) are commonly used to transfer large-scale Global Climate Model (GCM) data to smaller scales and to provide more detailed regional information. However, there are often considerable biases in RCM simulations, which have led to the development of a number of bias correction approaches to provide more realistic climate simulations for impact studies. Bias correction procedures rely on the assumption that RCM biases do not change over time, because correction algorithms and their parameterizations are derived for current climate conditions and assumed to apply also for future climate conditions. This underlying assumption of bias stationarity is the main concern when using bias correction procedures. It is in principle not possible to test whether this assumption is actually fulfilled for future climate conditions. In this study, however, we demonstrate that it is possible to evaluate how well bias correction methods perform for conditions different from those used for calibration. For five Swedish catchments, several time series of RCM simulated precipitation and temperature were obtained from the ENSEMBLES data base and different commonly-used bias correction methods were applied. We then performed a differential split-sample test by dividing the data series into cold and warm respective dry and wet years. This enabled us to evaluate the performance of different bias correction procedures under systematically varying climate conditions. The differential split-sample test resulted in a large spread and a clear bias for some of the correction methods during validation years. More advanced correction methods such as distribution mapping performed relatively well even in the validation period, whereas simpler approaches resulted in the largest deviations and least reliable corrections for changed conditions. Therefore, we question the use of simple bias correction methods such as the widely used delta-change approach and linear scaling for RCM-based climate-change impact studies and recommend using higher-skill bias correction methods.

scholarly journals Proteogenomic characterization of the pathogenic fungus Aspergillus flavus reveals novel genes involved in aflatoxin production

2020 ◽  
pp. mcp.RA120.002144
Author(s):  
Mingkun Yang ◽  
Zhuo Zhu ◽  
Zhenhong Zhuang ◽  
Youhuang Bai ◽  
Shihua Wang ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Stress Responses ◽  
Splice Variants ◽  
Pathogenic Fungus ◽  
Aflatoxin Production ◽  
Mass Spectrometry Data ◽  
Single Amino Acid ◽  
High Quality ◽  
Novel Proteins ◽  
Wide Range

Aspergillus flavus (A. flavus), a pathogenic fungus, can produce carcinogenic and toxic aflatoxins that are a serious agricultural and medical threat worldwide. Attempts to decipher the aflatoxin biosynthetic pathway have been hampered by the lack of a high-quality genome annotation for A. flavus. To address this gap, we performed a comprehensive proteogenomic analysis using high-accuracy mass spectrometry data for this pathogen. The resulting high-quality dataset confirmed the translation of 8,724 previously-predicted genes, and identified 732 novel proteins, 269 splice variants, 447 single amino acid variants, 188 revised genes. A subset of novel proteins was experimentally validated by RT-PCR and synthetic peptides. Further functional annotation suggested that a number of the identified novel proteins may play roles in aflatoxin biosynthesis and stress responses in A. flavus. This comprehensive strategy also identified a wide range of post-translational modifications (PTMs), including 3,461 modification sites from 1,765 proteins. Functional analysis suggested the involvement of these modified proteins in the regulation of cellular metabolic and aflatoxin biosynthetic pathways. Together, we provided a high quality annotation of A. flavus genome and revealed novel insights into the mechanisms of aflatoxin production and pathogenicity in this pathogen.

scholarly journals Regulation of Morphology, Aflatoxin Production, and Virulence of Aspergillus flavus by the Major Nitrogen Regulatory Gene areA

Toxins ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 718 ◽  
Author(s):  
Opemipo Esther Fasoyin ◽  
Kunlong Yang ◽  
Mengguang Qiu ◽  
Bin Wang ◽  
Sen Wang ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Regulatory Gene ◽  
Nitrogen Sources ◽  
Aflatoxin Production ◽  
Fungal Species ◽  
Complete Medium ◽  
Over Expression ◽  
Oxidative Stresses ◽  
Gata Transcription Factor

Aspergillus flavus is a renowned plant, animal and human pathogen. areA is a global nitrogen regulatory gene of the GATA transcription factor family, shown to be the major nitrogen regulator. In this study, we identified areA in A. flavus and studied its function. The AreA protein contained a signatory zinc finger domain, which is extremely conserved across fungal species. Gene deletion (ΔareA) and over-expression (OE::areA) strains were constructed by homologous recombination to elucidate the role of areA in A. flavus. The ΔareA strain was unable to efficiently utilize secondary nitrogen sources for growth of A. flavus, and it had poorly developed conidiophores, when observed on complete medium, resulting in the production of significantly less conidia than the wild-type strain (WT). Aflatoxin B1 (AFB1) production was reduced in ΔareA compared with the WT strain in most conditions tested, and ΔareA had impaired virulence in peanut seeds. areA also played important roles in the sensitivity of A. flavus to osmotic, cell wall and oxidative stresses. Hence, areA was found to be important for the growth, aflatoxin production and pathogenicity of A. flavus. This work sheds light on the function of areA in the regulation of the nitrogen metabolism of A. flavus, and consequently aims at providing new ways for controlling the crossover pathogen, A. flavus.

Adaptation and mitigation strategies for dairy cattle: Myths and realities in Indian condition -A review

2015 ◽  
Vol 36 (4) ◽  
Author(s):  
Sumit Mahajan ◽  
Janailin S. Papang ◽  
Shivraj Singh ◽  
K. K. Datta
Keyword(s):  
Climate Change ◽  
Smallholder Farmers ◽  
Mitigation Strategies ◽  
Farm Households ◽  
Local Conditions ◽  
Climate Conditions ◽  
Change Impact ◽  
Vector Borne ◽  
The Impact ◽  
Adaptation And Mitigation

The anticipated climate change will adversely affect the productivity of livestock directly due to increased heat stress, indirectly it will affect the livestock by causing feed and fodder shortages, reducing biodiversity, water availability and increasing the incidences of vector-borne livestock diseases. On the other hand, the livestock keeping farm households mainly small farm households will be affected directly as they rear livestock for their livelihood. Interestingly, over the years, the livestock keeping households have increased at a tremendous rate for the small and marginal, medium and semimedium farm household categories as they reduce the risk arising from extreme climate conditions. So, it becomes imperative to adopt adaptation and mitigation strategies to reduce the impact of climate change on livestock given their importance in smallholder farmers’ livelihood in India. Some of researchers in past have recommended certain adaptation and mitigation strategies for reducing the climate change impact on livestock. But, are these adaptation and mitigation strategies applicable or viable in the context of smallholder farmers in India? This remains an unsolved puzzle. This paper tries to demystify certain myths associated with these strategies as well as explore the ground realities. The present policy of indiscriminate crossbreeding of local cattle with exotic cattle should be reviewed and reoriented for smallholder dairy farmer especially, in dry and rainfed regions where there is scarcity of fodder and water which are required heavily by crossbred cattle. The study clearly reflects that the adaptation research should be country specific as the strategies suitable for one country may not be viable for the others as there is considerable difference in local conditions of different countries.

Influence of refrigeration on aflatoxin production by strains of Aspergillus flavus

1969 ◽  
Vol 15 (6) ◽  
pp. 629-632 ◽  
Author(s):  
W. van Walbeek ◽  
T. Clademenos ◽  
F. S. Thatcher
Keyword(s):  
Aspergillus Flavus ◽  
Room Temperature ◽  
Aflatoxin Production ◽  
Toxin Production ◽  
Experimental Conditions ◽  
Liquid Cultures ◽  
High Concentrations

Strains of Aspergillus flavus that produce high concentrations of aflatoxin in cultures incubated at room temperature also produced these toxins in significant concentrations under conditions simulating household refrigeration (7.5° to 10 °C). The rate of toxin production at 10 °C was markedly influenced by preincubating cultures at room temperature for 24 hours. Solid cultures yielded higher concentrations of toxin than liquid cultures under the prevailing experimental conditions.

scholarly journals The Climate Change Impact On Grapevine Productivity

2015 ◽  
Vol 9 (2) ◽  
pp. 5-16
Author(s):  
Nedealcov Maria ◽  
Sîrbu Rodica
Keyword(s):  
Climate Change ◽  
National Economy ◽  
Climatic Conditions ◽  
Meteorological Conditions ◽  
Regional Level ◽  
Climate Conditions ◽  
Republic Of Moldova ◽  
Northern Border ◽  
Change Impact ◽  
The Republic

Abstract The viticulture, a traditional branch of the national economy, is closely related to climatic conditions because the Republic of Moldova territory represents the northern border of its territorial location. Therefore the knowledge of regional particularities of grapevine productivity formation in dependence of current agro-climatic conditions is of particular interest. Along with accelerated climate change in last decades over the Republic of Moldova territory, we find that are essential changes concerning agro-meteorological conditions, at the same time comprehensive researches that would reflect the actual impact of climate change on grapevine are limited. There are known researches, but in the context of changes that occur at regional level it is necessary to supplement permanently the database in order to elaborate an appropriate estimation of current climate conditions. The above reported facts show the importance of parameters influencing the grapevine productivity time and space study in Republic of Moldova.

Effect of Laminarin on Aspergillus Flavus Growth and Aflatoxin Production

2011 ◽  
Vol 343-344 ◽  
pp. 1168-1171 ◽  
Author(s):  
Liang Bin Hu ◽  
Hong Bo Li ◽  
Jun Liang Sun ◽  
Jie Zeng
Keyword(s):  
Liquid Medium ◽  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Biological Activities ◽  
Aflatoxin Production ◽  
Toxin Production ◽  
Aflatoxin Contamination ◽  
Laminaria Digitata ◽  
Inhibitory Effects ◽  
Mycelium Growth

Control of aflatoxin contamination has been a worldwide problem. Laminarin from Laminaria digitata is one kind of polysaccharides with multiple biological activities. In this paper, the inhibitory effects of Laminarin on the growth and toxin production of A. flavus was studied. The results indicated that 150 and 200 µg/mL of Laminarin ccould significantly inhibit the aflatoxin production in Sabouraud liquid medium (Sab), without affecting mycelium growth. In addition, the results also showed that certain concentration Laminaria could decrease the infection of peanut seeds by A. flavus as well as the contamination by aflatoxin B1.

Climate change factors and Aspergillus flavus: effects on gene expression, growth and aflatoxin production

2015 ◽  
Vol 8 (2) ◽  
pp. 171-179 ◽  
Author(s):  
Á Medina ◽  
A. Rodríguez ◽  
Y. Sultan ◽  
N. Magan
Keyword(s):  
Climate Change ◽  
Gene Expression ◽  
Water Stress ◽  
Aspergillus Flavus ◽  
Climatic Factors ◽  
Aflatoxin Production ◽  
Scientific Data ◽  
Effect Of Temperature ◽  
Mycotoxigenic Fungi ◽  
The Impact

The objectives of this study were to obtain scientific data on the impact that interactions between water stress (water activity (aw); 0.97, 0.95, 0.92), temperature (34, 37 °C) and CO2 exposure (350, 650, 1000 ppm) may have on the growth, gene expression of biosynthetic genes (aflD, aflR), and phenotypic aflatoxin B1 (AFB1) production by a type strain of Aspergillus flavus on a conducive medium. The study showed that while aw affected growth there was no statistically significant effect of temperature or CO2 exposure. The effect of these interacting factors on aflD and aflR gene expression showed that at 34 °C there was maximum relative expression of aflD under the control conditions (34 °C, 350 ppm) with a decrease in expression with elevated CO2 and water stress. For aflR expression at 34 °C, there was a significant increase in expression, but only at 0.92 aw and 650 ppm CO2. However, at 37 °C, there was a significant increase in expression of both aflD and aflR at 0.95 and 0.92 aw and 650 and 1000 ppm CO2. There was an associated increase in AFB1 in these treatments. In contrast, at 34 °C there were no significant differences for interacting treatments. This is the first study to examine these three-way interacting climatic factors on growth and mycotoxin production by a strain of A. flavus. This provides data that are necessary to help predict the real impacts of climate change on mycotoxigenic fungi.

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