scholarly journals Metarhizium robertsii protease and conidia production, response to heat stress and virulence against Aedes aegypti larvae

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Juliana M. Ferreira ◽  
Salorrane M. N. Pinto ◽  
Filippe E. F. Soares
Keyword(s):  
Heat Stress ◽  
Abiotic Stress ◽  
Aedes Aegypti ◽  
Sodium Nitrate ◽  
Culture Medium ◽  
Stress Factors ◽  
Metarhizium Robertsii ◽  
Significant Difference ◽  
Conidia Production ◽  
Solid Fermentation

AbstractNutritional factors exert significant influence on the growth of entomopathogenic fungi, one of the main agents employed commercially in the biological control of arthropods. Thus, the objective of this work is to optimize the culture medium and solid fermentation time for production of proteases and conidia of Metarhizium robertsii ARSEF 2575 and to evaluate the interference of riboflavin and salts on virulence and resistance to abiotic stress factors. In the first step, nine groups were separated: negative control, positive control, and seven supplementation groups: ammonium nitrate, ammonium chloride, potassium nitrate, sodium nitrate, ammonium sulfate, ammonium phosphate, urea. Sodium nitrate showed significant difference in protease production at the time of 20 days of solid fermentation. Then, different concentrations of sodium nitrate and riboflavin as supplement were evaluated. Response surface methodology demonstrated that riboflavin and sodium nitrate influence proteolytic activity and conidia production, but without synergism. Supplementation of the medium with the optimal concentration of sodium nitrate and riboflavin did not interfere with the germination of conidia without exposure to abiotic stress, but did increase the thermotolerance of conidia. The presence of riboflavin and sodium nitrate at optimal concentrations in the culture medium did not alter fungal virulence with and without exposure to heat stress, varying according to the presence or absence of the supernatant during exposure, evidencing that resistance to heat exposure is multifactorial and dependent on intra- and extracellular factors. Moreover, the supplementation increased the larvicidal activity of the supernatant against Aedes aegypti.

scholarly journals Effect of Abiotic Stress on Irrigated Maize Forage Yield as Compared to Sorghum

2019 ◽  
Vol 6 ◽  
pp. 27-36
Author(s):  
S.H. Mohammed ◽  
Maarouf I. Mohammed
Keyword(s):  
Salt Stress ◽  
Heat Stress ◽  
Abiotic Stress ◽  
Water Stress ◽  
Salt Water ◽  
Block Design ◽  
Forage Yield ◽  
Stress Factors ◽  
Yield Reduction ◽  
Forage Maize

A study was conducted in Sudan (Africa) during the summer and winter seasons (2013 – 2014) at two locations: Shambat (normal soils) and Soba (salt affected soils). Nine maize (Zeamays L.) and sorghum (Sorghum bicolor (L.) Moench) cultivars were studied under two watering regimes arranged in split plot experiment in randomized complete block design. The eight test-environments created by the combination of locations, seasons and watering regimes were used to investigate the effect of salt, water and heat stresses on forage yield and some related traits. The results showed that separate and combined stress factors significantly reduced forage yield. The greatest reduction in dry matter yield caused by one factor was shown by salt stress (29.6%) and the least reduction was caused by heat stress (3.9%). Water stress coupled with either heat or salt stress caused the greater reduction in yield (37.0%-43.3%) than the combination of the other factors. Full stress caused 53.8% yield reduction. Days to tasseling was significantly reduced by heat stress whereas water and salt stress showed no significant effect on tasseling duration. Full stress caused the greatest effect on days to tasseling. Plant height and stem diameter were significantly reduced by salt and water stress. Two hybrids kept top rank in yield through most abiotic stress levels showing resilience to unfavorable environments. All maize genotypes significantly outyielded the sorghum check under no heat stress (winter sowing) regardless the effect of salt and water stresses while the opposite is true under the heat stress (summer sowing). It was concluded that salt and water stress are the major abiotic stresses limiting forage maize production. Maize tolerate better reduction in temperature than dose sorghum while the latter tolerate better salt and water stresses than dose maize. Forage maize could be competitively grown during summer if water and salt stresses are avoided

Temperature dependence of wheat development

2008 ◽  
Vol 56 (3) ◽  
pp. 313-320 ◽  
Author(s):  
K. Balla ◽  
O. Veisz
Keyword(s):  
Heat Stress ◽  
Abiotic Stress ◽  
High Temperatures ◽  
Substantial Reduction ◽  
Vegetation Period ◽  
Stress Factors ◽  
Wheat Varieties ◽  
Rapid Decomposition ◽  
Abiotic Stress Factors ◽  
Temperature Levels

Among the abiotic stress factors influencing the growth and productivity of wheat varieties, extremely high temperatures have the most limiting effect. In an experiment set up in the gradient chamber of the Martonvásár phytotron to test the effect of various temperatures on four winter wheat varieties and one variety of spelt, substantial differences were observed in the heat stress tolerance of the varieties. There was a considerable reduction in the number of shoots and spikes as the result of heat stress, leading to a drastic loss of grain yield. It was clear from changes in the biomass and in the grain:straw ratio that extremely high temperatures led to a substantial reduction in the ratio of grain to straw in the varieties tested. In response to high temperature the wheat plants turned yellow earlier due to the rapid decomposition of the chlorophyll content. This resulted in a considerable shortening of the vegetation period and early ripening. Reductions in the parameters tested were observed at different temperature levels for each variety, indicating considerable differences in the ability of the varieties to adapt to abiotic stress factors.

PSXVI-8 Taxifolin impact on the consequences of moderate heat stress in fattening pigs

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 416-417
Author(s):  
Roman V Nekrasov ◽  
Nadezhda V Bogolyubova ◽  
Magomed G Chabaev ◽  
Roman A Rykov ◽  
Alexey V Mishurov ◽  
...  
Keyword(s):  
Heat Stress ◽  
Stress Factors ◽  
Control Group ◽  
Negative Effects ◽  
Russian Science ◽  
Significant Difference ◽  
Group A ◽  
Group 3 ◽  
Fattening Period ◽  
Group 2

Abstract The research aim is to study the efficiency of feeding Taxifolin (TAX) to pigs under moderate heat stress conditions. The experiment was performed on crossbred ((BWxL)xD) pigs (BW1=17.2–17.4 kg, 58 days old, n = 27) during the fattening period. The animals were in 3 groups: Group 1-control (standard forage-SF, n = 9), Group 2-experimental (SF+32 mg/kg Tax, n = 9), Group 3-experimental (SF, feeding Tax (32 mg/kg) periodically for 7 days at the beginning and at the end of the experiment, as well as when changing feeds, n = 9). To simulate moderate heat stress, the temperature was within the range of +24.0...+27.5°C with a humidity of 60–85%. The TAX effect manifested as an “adaptive factor”, contributing to a decrease of blood cortisol in experimental Groups 2&3 in comparison with the Control Group in the middle (93.5±16.2&133.7±16.6 vs. 147.6±27.5, nmol/l, P < 0.5) and at the end of the experiment (234.4±61.2&253.2±46.4 vs. 284.8±86.8, nmol/l, P > 0.5). Under TAX influence the concentration of blood TBARS decreased by 11.44 (P < 0.05) and 11.80% (P < 0.01) against the control group (2.40±0.12&2.39±0.08 vs. 2.71±0.05, µmol/l). The use of TAX improved ADG in the experimental groups (Week 1, Group 2, P < 0.05; Week 8, Experimental Groups 2&3, p< 0.05) in comparison with the Control Group. A more significant difference in ADG was observed in the final fattening period (1062.2±25.0&1049.9±19.9 vs. 1000.3±24.9, g, P = 0.01), and in general, for the entire fattening period (120 days of experience), ADG was 887.9±13.2&881.6±15.8 vs. 865.2±12.0 g in Control (P > 0.5). In the experimental groups, there was a tendency (75.2±0.4&74.8±0.2 vs. 73.9±0.4, %, P < 0.1) to increase the digestibility of dry matter of feed at the end of fattening. Thus, it was found that feeding TAX to pigs prevents the negative effects of temperature stress factors. The work was supported by Grant No. 19-16-00068 of the Russian Science Foundation.

scholarly journals Transcriptomic Analysis of Rice Plants Overexpressing PsGAPDH in Response to Salinity Stress

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 641
Author(s):  
Hyemin Lim ◽  
Hyunju Hwang ◽  
Taelim Kim ◽  
Soyoung Kim ◽  
Hoyong Chung ◽  
...  
Keyword(s):  
Salt Stress ◽  
Abiotic Stress ◽  
Salinity Stress ◽  
Functional Enrichment ◽  
Differentially Expressed ◽  
Pathway Enrichment Analysis ◽  
Sequencing Data ◽  
Illumina Hiseq ◽  
Rice Plants ◽  
Significant Difference

In plants, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a main enzyme in the glycolytic pathway. It plays an essential role in glycerolipid metabolism and response to various stresses. To examine the function of PsGAPDH (Pleurotus sajor-caju GAPDH) in response to abiotic stress, we generated transgenic rice plants with single-copy/intergenic/homozygous overexpression PsGAPDH (PsGAPDH-OX) and investigated their responses to salinity stress. Seedling growth and germination rates of PsGAPDH-OX were significantly increased under salt stress conditions compared to those of the wild type. To elucidate the role of PsGAPDH-OX in salt stress tolerance of rice, an Illumina HiSeq 2000 platform was used to analyze transcriptome profiles of leaves under salt stress. Analysis results of sequencing data showed that 1124 transcripts were differentially expressed. Using the list of differentially expressed genes (DEGs), functional enrichment analyses of DEGs such as Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were performed. KEGG pathway enrichment analysis revealed that unigenes exhibiting differential expression were involved in starch and sucrose metabolism. Interestingly, trehalose-6-phosphate synthase (TPS) genes, of which expression was enhanced by abiotic stress, showed a significant difference in PsGAPDH-OX. Findings of this study suggest that PsGAPDH plays a role in the adaptation of rice plants to salt stress.

scholarly journals Implementation of a deep learning model for automated classification of Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) in real time

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Song-Quan Ong ◽  
Hamdan Ahmad ◽  
Gomesh Nair ◽  
Pradeep Isawasan ◽  
Abdul Hafiz Ab Majid
Keyword(s):  
Deep Learning ◽  
Aedes Aegypti ◽  
Real Time ◽  
Aedes Albopictus ◽  
Automated Classification ◽  
Expert Performance ◽  
Deep Convolutional Neural Networks ◽  
Significant Difference ◽  
Set Up

AbstractClassification of Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) by humans remains challenging. We proposed a highly accessible method to develop a deep learning (DL) model and implement the model for mosquito image classification by using hardware that could regulate the development process. In particular, we constructed a dataset with 4120 images of Aedes mosquitoes that were older than 12 days old and had common morphological features that disappeared, and we illustrated how to set up supervised deep convolutional neural networks (DCNNs) with hyperparameter adjustment. The model application was first conducted by deploying the model externally in real time on three different generations of mosquitoes, and the accuracy was compared with human expert performance. Our results showed that both the learning rate and epochs significantly affected the accuracy, and the best-performing hyperparameters achieved an accuracy of more than 98% at classifying mosquitoes, which showed no significant difference from human-level performance. We demonstrated the feasibility of the method to construct a model with the DCNN when deployed externally on mosquitoes in real time.

scholarly journals PSV-6 Effects of chilled drinking water and cooled floor pads on behavior of lactating sows under heat stress

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 153-154
Author(s):  
Yuzhi Li ◽  
Yunhui Zhu ◽  
Michael Reese ◽  
Eric Buchanan ◽  
Lee Johnston
Keyword(s):  
Drinking Water ◽  
Heat Stress ◽  
Time Budget ◽  
Calculated Data ◽  
Video Recordings ◽  
Significant Difference ◽  
Lactating Sows ◽  
Effect Of Treatment ◽  
Drinking Frequency ◽  
And Control

Abstract This study was conducted to evaluate effects of chilled drinking water and cooled floor pads on behavior of lactating sows under heat stress. Sows were housed in individual farrowing stalls in two rooms with temperatures being controlled at 29.4°C (0700h to 1900h) and 23.9°C (1900h to 0700h). Sows in one room (treatment), but not in the other room (control) were provided with chilled drinking water (13 to 15°C) and cooled floor pads (15 to 18°C). Behavior of sows (n=15 sows/treatment; parity=1 to 6) was video recorded during farrowing, and d 1, 3, 7, 14, and 21 after farrowing. Videos were viewed to register birth time of each piglet. Number of drinking bouts and duration of each bout were registered for 2 h (1530h to 1730h) each day after farrowing. Postures (lying laterally, lying ventrally, sitting, and standing) were recorded by scanning video-recordings at 5-min intervals for 24 h each day after farrowing, and time budget for each posture was calculated. Data were analyzed using the Glimmix Procedure of SAS. No effect of treatment was detected for litter size born, farrowing duration, or birth interval (P >0.33; Table 1). Neither frequency nor duration of drinking bouts was affected by treatment (P >0.27). No significant difference was observed in time budget for each posture (P >0.46) between treatment and control groups. As lactation progressed, sows increased drinking frequency (from 1.2 drinks/2h on d 1 to 4.9 drinks/2h on d 21; P< 0.001) and time spent lying ventrally (8% to 14%; P< 0.0001), standing (4% to 10%; P< 0.001), and sitting (2% to 4%; P< 0.0001), and decreased time spent lying laterally (86% to 67%; P< 0.0001) in both control and treatment rooms. These results indicate that chilled drinking water and cooled floor pads did not affect behavior of sows during farrowing and lactation in the current study.

scholarly journals Assessing the Potential of Extra-Early Maturing Landraces for Improving Tolerance to Drought, Heat, and Both Combined Stresses in Maize

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 318 ◽  
Author(s):  
Charles Nelimor ◽  
Baffour Badu-Apraku ◽  
Antonia Yarney Tetteh ◽  
Ana Luísa Garcia-Oliveira ◽  
Assanvo Simon-Pierre N’guetta
Keyword(s):  
Heat Stress ◽  
Abiotic Stress ◽  
Field Experiments ◽  
Yield Loss ◽  
Yield Potential ◽  
Genetic Base ◽  
Maize Varieties ◽  
Early Maturing ◽  
Maize Landraces ◽  
Landrace Accessions

Maize landrace accessions constitute an invaluable gene pool of unexplored alleles that can be harnessed to mitigate the challenges of the narrowing genetic base, declined genetic gains, and reduced resilience to abiotic stress in modern varieties developed from repeated recycling of few superior breeding lines. The objective of this study was to identify extra-early maize landraces that express tolerance to drought and/or heat stress and maintain high grain yield (GY) with other desirable agronomic/morpho-physiological traits. Field experiments were carried out over two years on 66 extra-early maturing maize landraces and six drought and/or heat-tolerant populations under drought stress (DS), heat stress (HS), combined both stresses (DSHS), and non-stress (NS) conditions as a control. Wide variations were observed across the accessions for measured traits under each stress, demonstrating the existence of substantial natural variation for tolerance to the abiotic stresses in the maize accessions. Performance under DS was predictive of yield potential under DSHS, but tolerance to HS was independent of tolerance to DS and DSHS. The accessions displayed greater tolerance to HS (23% yield loss) relative to DS (49% yield loss) and DSHS (yield loss = 58%). Accessions TZm-1162, TZm-1167, TZm-1472, and TZm-1508 showed particularly good adaptation to the three stresses. These landrace accessions should be further explored to identify the genes underlying their high tolerance and they could be exploited in maize breeding as a resource for broadening the genetic base and increasing the abiotic stress resilience of elite maize varieties.

scholarly journals Jute Responses and Tolerance to Abiotic Stress: Mechanisms and Approaches

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1595
Author(s):  
Khussboo Rahman ◽  
Naznin Ahmed ◽  
Md. Rakib Hossain Raihan ◽  
Farzana Nowroz ◽  
Faria Jannat ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Stress Responses ◽  
Growth Yield ◽  
Climatic Conditions ◽  
Stress Factors ◽  
Growth Physiology ◽  
Abiotic Stress Factors ◽  
Hot And Humid Climates ◽  
Adverse Environmental Conditions ◽  
Cold Metal

Jute (Corchorus spp.) belongs to the Malvaceae family, and there are two species of jute, C. capsularis and C. olitorious. It is the second-largest natural bast fiber in the world according to production, which has diverse uses not only as a fiber but also as multiple industrial materials. Because of climate change, plants experience various stressors such as salt, drought, heat, cold, metal/metalloid toxicity, and flooding. Although jute is particularly adapted to grow in hot and humid climates, it is grown under a wide variety of climatic conditions and is relatively tolerant to some environmental adversities. However, abiotic stress often restricts its growth, yield, and quality significantly. Abiotic stress negatively affects the metabolic activities, growth, physiology, and fiber yield of jute. One of the major consequences of abiotic stress on the jute plant is the generation of reactive oxygen species, which lead to oxidative stress that damages its cellular organelles and biomolecules. However, jute’s responses to abiotic stress mainly depend on the plant’s age and type and duration of stress. Therefore, understanding the abiotic stress responses and the tolerance mechanism would help plant biologists and agronomists in developing climate-smart jute varieties and suitable cultivation packages for adverse environmental conditions. In this review, we summarized the best possible recent literature on the plant abiotic stress factors and their influence on jute plants. We described the possible approaches for stress tolerance mechanisms based on the available literature.

Susceptibility of Aedes Aegypti Against Various Insecticides in Lahore, Pakistan

2021 ◽  
Author(s):  
Farkhanda Manzoor ◽  
Rooma Adalat ◽  
Tallat Anwar Faridi ◽  
Wafa Fatima ◽  
Muhammad Moazzam ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Wild Strain ◽  
Effective Vaccine ◽  
P Value ◽  
Significant Difference ◽  
Incomplete Coverage ◽  
Wild Strains ◽  
New Strategies ◽  
Lahore City ◽  
Indoor And Outdoor

Dengue fever is an arbo-viral infection, widespread all over the world. In 21th Century, there is no safe affordable and effective vaccine accessible yet; vector control is that most effective method for the control of the disease Objective: To determine the susceptibility status of wild and laboratory strains larvae and adults of Aedes aegypti against different group of insecticides in Lahore city. Method: From Lahore sites, larvae were collected where insecticides used for wild strain at high frequency and quantity. The Insectary of National Institute of Malaria Research and Training (NIMRT), Lahore, Pakistan, adults and larvae were collected for laboratory strain.The laboratory strains for larvae bioassays were used. The mosquitoes populations indoor and outdoor collected in 2009, hatched from larvae into adults insectary in Lahore, Pakistan. During this study, four major insecticides groups are used which include Pyrethroids (Deltamethrine 2.5% SC), Neonicotenoids (Imidacloprid 5% SC), Phenyl-pyrazoles (Fipronil 2.5% EC) and Organophosphates dichlorvos (DDVP 50% EC). For data analysis, Minitab statistical software (Version 13.20) used for data expressed as mean ± S.E.M from bioassays. By using EPA Probit, LC was estimated with 95% confidence. The 50 statistically significant p value was <= 0.05. For comparing the concentrations of insecticides, Duncan's multiple range tests was used with significant difference (5% level) using at New Costat. Results: Different location of Lahore samples, Imidacloprid the most toxic to Aedes aegypti's wild strains on the other hand while Fipronil was also active for wild larval samples. Deltamethrine showed least activity against both adults and larval strains. The susceptibility of the eld strains was lower than laboratory strains; resistant ratio varies from insecticide to insecticide. In reporting results, mosquitos' population was resistance because of infrequent and incomplete coverage. Conclusions: This study concluded that Pyrethroids and agriculture pest control play role in indirect growth of insecticides' classes. Based on this study it is suggested that by using new strategies to prevent and delay in growth of insecticides will helpful in Lahore, city, Pakistan.

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