scholarly journals Aspergillus flavus NRRL 35739, a Poor Biocontrol Agent, May Have Increased Relative Expression of Stress Response Genes

2019 ◽  
Vol 5 (2) ◽  
pp. 53 ◽  
Author(s):  
Kayla K. Pennerman ◽  
Guohua Yin ◽  
Joan W. Bennett ◽  
Sui-Sheng T. Hua
Keyword(s):  
Stress Response ◽  
Aspergillus Flavus ◽  
Genetic Basis ◽  
Biocontrol Agent ◽  
Success Rates ◽  
Lower Stress ◽  
Relative Expression ◽  
Stress Response Genes ◽  
Variable Success ◽  
Aflatoxin Accumulation

Biocontrol of the mycotoxin aflatoxin utilizes non-aflatoxigenic strains of Aspergillus flavus, which have variable success rates as biocontrol agents. One non-aflatoxigenic strain, NRRL 35739, is a notably poor biocontrol agent. Its growth in artificial cultures and on peanut kernels was found to be slower than that of two aflatoxigenic strains, and NRRL 35739 exhibited less sporulation when grown on peanuts. The non-aflatoxigenic strain did not greatly prevent aflatoxin accumulation. Comparison of the transcriptomes of aflatoxigenic and non-aflatoxigenic A. flavus strains AF36, AF70, NRRL 3357, NRRL 35739, and WRRL 1519 indicated that strain NRRL 35739 had increased relative expression of six heat shock and stress response proteins, with the genes having relative read counts in NRRL 35739 that were 25 to 410 times more than in the other four strains. These preliminary findings tracked with current thought that aflatoxin biocontrol efficacy is related to the ability of a non-aflatoxigenic strain to out-compete aflatoxigenic ones. The slower growth of NRRL 35739 might be due to lower stress tolerance or overexpression of stress response(s). Further study of NRRL 35739 is needed to refine our understanding of the genetic basis of competitiveness among A. flavus strains.

scholarly journals AITRL, an evolutionarily conserved plant specific transcription repressor regulates ABA response in Arabidopsis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yanxing Ma ◽  
Hainan Tian ◽  
Rao Lin ◽  
Wei Wang ◽  
Na Zhang ◽  
...  
Keyword(s):  
Stress Response ◽  
Protein Phosphatase ◽  
Aba Signaling ◽  
Response Gene ◽  
Stress Response Genes ◽  
Arabidopsis Protein ◽  
Evolutionarily Conserved ◽  
Increased Sensitivity ◽  
Aba Response ◽  
Transcription Repressors

AbstractExpression of stress response genes can be regulated by abscisic acid (ABA) dependent and ABA independent pathways. Osmotic stresses promote ABA accumulation, therefore inducing the expression of stress response genes via ABA signaling. Whereas cold and heat stresses induce the expression of stress response genes via ABA independent pathway. ABA induced transcription repressors (AITRs) are a family of novel transcription factors that play a role in ABA signaling, and Drought response gene (DRG) has previously been shown to play a role in regulating plant response to drought and freezing stresses. We report here the identification of DRG as a novel transcription factor and a regulator of ABA response in Arabidopsis. We found that the expression of DRG was induced by ABA treatment. Homologs searching identified AITR5 as the most closely related Arabidopsis protein to DRG, and homologs of DRG, including the AITR-like (AITRL) proteins in bryophytes and gymnosperms, are specifically presented in embryophytes. Therefore we renamed DRG as AITRL. Protoplast transfection assays show that AITRL functioned as a transcription repressor. In seed germination and seedling greening assays, the aitrl mutants showed an increased sensitivity to ABA. By using qRT-PCR, we show that ABA responses of some ABA signaling component genes including some PYR1-likes (PYLs), PROTEIN PHOSPHATASE 2Cs (PP2Cs) and SUCROSE NONFERMENTING 1 (SNF1)-RELATED PROTEIN KINASES 2s (SnRK2s) were reduced in the aitrl mutants. Taken together, our results suggest that AITRLs are a family of novel transcription repressors evolutionally conserved in embryophytes, and AITRL regulates ABA response in Arabidopsis by affecting ABA response of some ABA signaling component genes.

scholarly journals Identification of the Genetic Basis of Response to de-Acclimation in Winter Barley

2021 ◽  
Vol 22 (3) ◽  
pp. 1057
Author(s):  
Magdalena Wójcik-Jagła ◽  
Agata Daszkowska-Golec ◽  
Anna Fiust ◽  
Przemysław Kopeć ◽  
Marcin Rapacz
Keyword(s):  
Enzyme Activity ◽  
Stress Response ◽  
Genetic Basis ◽  
Differential Expression Analysis ◽  
Winter Barley ◽  
Developmental Changes ◽  
Molecular Regulation ◽  
Quantitative Real Time Pcr ◽  
Breeding Lines ◽  
Functionally Diverse

Mechanisms involved in the de-acclimation of herbaceous plants caused by warm periods during winter are poorly understood. This study identifies the genes associated with this mechanism in winter barley. Seedlings of eight accessions (four tolerant and four susceptible to de-acclimation cultivars and advanced breeding lines) were cold acclimated for three weeks and de-acclimated at 12 °C/5 °C (day/night) for one week. We performed differential expression analysis using RNA sequencing. In addition, reverse-transcription quantitative real-time PCR and enzyme activity analyses were used to investigate changes in the expression of selected genes. The number of transcripts with accumulation level changed in opposite directions during acclimation and de-acclimation was much lower than the number of transcripts with level changed exclusively during one of these processes. The de-acclimation-susceptible accessions showed changes in the expression of a higher number of functionally diverse genes during de-acclimation. Transcripts associated with stress response, especially oxidoreductases, were the most abundant in this group. The results provide novel evidence for the distinct molecular regulation of cold acclimation and de-acclimation. Upregulation of genes controlling developmental changes, typical for spring de-acclimation, was not observed during mid-winter de-acclimation. Mid-winter de-acclimation seems to be perceived as an opportunity to regenerate after stress. Unfortunately, it is competitive to remain in the cold-acclimated state. This study shows that the response to mid-winter de-acclimation is far more expansive in de-acclimation-susceptible cultivars, suggesting that a reduced response to the rising temperature is crucial for de-acclimation tolerance.

scholarly journals Characterization of the Maize Chitinase Genes and Their Effect on Aspergillus flavus and Aflatoxin Accumulation Resistance

PLoS ONE ◽  
2015 ◽  
Vol 10 (6) ◽  
pp. e0126185 ◽  
Author(s):  
Leigh K. Hawkins ◽  
J. Erik Mylroie ◽  
Dafne A. Oliveira ◽  
J. Spencer Smith ◽  
Seval Ozkan ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Aflatoxin Accumulation ◽  
Chitinase Genes

Polymorphisms in stress response genes in Lactobacillus plantarum: implications for classification and heat stress response

2014 ◽  
Vol 65 (1) ◽  
pp. 297-305
Author(s):  
Angela Guidone ◽  
Eugenio Parente ◽  
Teresa Zotta ◽  
Caitriona M. Guinane ◽  
Mary C. Rea ◽  
...  
Keyword(s):  
Heat Stress ◽  
Stress Response ◽  
Lactobacillus Plantarum ◽  
Heat Stress Response ◽  
Stress Response Genes

Vitamin D regulates the expression of immune and stress response genes in dengue virus-infected macrophages by inducing specific microRNAs

MicroRNA ◽  
2021 ◽  
Vol 11 ◽  
Author(s):  
Geysson Javier Fernandez ◽  
Jorge Andrés Castillo ◽  
Diana Marcela Giraldo ◽  
Silvio Urcuqui-Inchima
Keyword(s):  
Vitamin D ◽  
Immune Response ◽  
Stress Response ◽  
Dengue Virus ◽  
Mirna Expression ◽  
Expression Profiles ◽  
Denv Infection ◽  
High Dose ◽  
Regulatory Pathways ◽  
Stress Response Genes

Background: The pathogenesis associated with Dengue virus (DENV) infection is marked by the impairment of host immune response. Consequently, the modulation of immune response has emerged as an important therapeutic target for the control of DENV infection. Vitamin D has been shown to regulate the immune response in DENV infection, although the molecular mechanism remains poorly understood. Post-transcriptional regulation of mRNA by miRNAs offers an opportunity to gain insight into the immunomodulation mediated by vitamin D Objective: Previously, it has been observed that a high dose of vitamin D (4000 IU) decreased DENV-2 infection and inflammatory response in monocyte-derived macrophages (MDMs). Here, we examine whether high or low doses of vitamin D supplements exert differential effect on miRNA expression in DENV-infected macrophages Methods: We analyzed miRNA expression profiles in MDMs isolated from healthy individuals who were given either 1000 or 4000 IU/day of vitamin D for 10 days. MDMs before or after vitamin D supplementation were challenged with DENV-2, and miRNAs profiles were analyzed by qPCR arrays. Results: DENV-2 infected MDMs supplemented with 4000 IU, showed up-regulation of miR-374a-5p, miR-363-3p, miR-101-3p, miR-9-5p, miR-34a-5p, miR-200a-3p, and the family of miRNAs miR-21-5p, and miR-590-p. The miRNA profile and predicted target mRNAs suggested regulatory pathways in MDMs obtained from healthy donors who received higher doses of vitamin D. These DENV-2 infected MDMs expressed a unique set of miRNAs that target immune and cellular stress response genes. Conclusion: The results suggest vitamin D dose-dependent differential expression of miRNAs target key signaling pathways of the pathogenesis of dengue disease.

Modelling the colonisation of maize by toxigenic and non-toxigenic Aspergillus flavus strains: implications for biological control

2008 ◽  
Vol 1 (3) ◽  
pp. 333-340 ◽  
Author(s):  
H. Abbas ◽  
R. Zablotowicz ◽  
H. Bruns
Keyword(s):  
Biological Control ◽  
Aspergillus Flavus ◽  
Growth Parameters ◽  
Biological Control Agent ◽  
Cyclopiazonic Acid ◽  
Aflatoxin Contamination ◽  
Tween 20 ◽  
Lag Phase ◽  
Gompertz Equation ◽  
Aflatoxin Accumulation

To successfully exploit biological control it is desirable to understand how the introduced agent colonises the host and interferes with establishment of the pest. This study assessed field colonisation of maize by Aspergillus flavus strains as biological control agents to reduce aflatoxin contamination. Maize (corn, Zea mays L.) ears were inoculated with A. flavus using a pin-bar technique in 2004 and 2005. Non-aflatoxigenic strains K49 (NRRL 30797) & CT3 (NRRL 30798) and toxigenic F3W4 (NRRL 30798) were compared against a carrier control (0.2% aqueous Tween 20). Ten ears were sampled over 12 to 20 days, visually assessed, and curves fit to a three compartment Gompertz equation or other best appropriate regressions. Aflatoxin was determined by HPLC and cyclopiazonic acid (CPA) by LC/MS. The Gompertz model describes growth parameters, e.g. growth constant, lag phase and maximum colonisation characterised patterns of maize colonisation for most inoculated treatments. Aflatoxin accumulation in maize inoculated with F3W4 was about 35,000 ng/g in 2004 and 2005, with kinetics of aflatoxin accumulation in 2005 well described by the Gompertz equation. Less than 200 ng/g was observed in maize inoculated with strains CT3 & K49 and accumulation was described by a linear or logistic model. Maize inoculated with strains CT3 and F3W4 accumulated a maximum of 220 and 169 µg/kg CPA, respectively, compared to 22 and 0.2 µg/kg in the control and K49 inoculated, respectively. This technique can be used to elucidate colonisation potential of non-toxigenic A. flavus in maize in relation to biological control of aflatoxin. The greatest reduction of aflatoxin and CPA in maize inoculated with strain K49 and Gompertz parameters on colonisation indicates its superiority to CT3 as a biological control agent. The dynamics of maize colonisation by A. flavus strains and subsequent mycotoxin accumulation generated by using the pin-bar technique has implications for characterising the competence of biocontrol strains for reducing aflatoxin contamination.

scholarly journals Anti-oxidative stress response genes: bioinformatic analysis of their expression and relevance in multiple cancers

Oncotarget ◽  
2013 ◽  
Vol 4 (12) ◽  
pp. 2577-2590 ◽  
Author(s):  
Barak Rotblat ◽  
Thomas G. P. Grunewald ◽  
Gabriel Leprivier ◽  
Gerry Melino ◽  
Richard A. Knight
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Bioinformatic Analysis ◽  
Oxidative Stress Response ◽  
Stress Response Genes ◽  
Multiple Cancers

scholarly journals Streptomyces roseolus, A Promising Biocontrol Agent Against Aspergillus flavus, the Main Aflatoxin B1 Producer

Toxins ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 442 ◽  
Author(s):  
Isaura Caceres ◽  
Selma Snini ◽  
Olivier Puel ◽  
Florence Mathieu
Keyword(s):  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Biocontrol Agent ◽  
Cyclopiazonic Acid ◽  
Over Expression ◽  
Expression Of Genes ◽  
B1 Gene ◽  
Genes Encoding ◽  
Molecular Mechanism Of Action ◽  
Potential Use

Crop contamination by aflatoxin B1 is a current problem in tropical and subtropical regions. In the future, this contamination risk may be expanded to European countries due to climate change. The development of alternative strategies to prevent mycotoxin contamination that further contribute to the substitution of phytopharmaceutical products are thus needed. For this, a promising method resides in the use of biocontrol agents. Several actinobacteria strains have demonstrated to effectively reduce the aflatoxin B1 concentration. Nevertheless, the molecular mechanism of action by which these biological agents reduce the mycotoxin concentration has not been determined. The aim of the present study was to test the potential use of Streptomyces roseolus as a biocontrol agent against aflatoxin B1 contamination. Co-cultures with Aspergillus flavus were conducted, and the molecular fungal response was investigated through analyzing the q-PCR expression of 65 genes encoding relevant fungal functions. Moreover, kojic and cyclopiazonic acid concentrations, as well as morphological fungal changes were also analyzed. The results demonstrated that reduced concentrations of aflatoxin B1 and kojic acid were respectively correlated with the down-regulation of the aflatoxin B1 gene cluster and kojR gene expression. Moreover, a fungal hypersporulated phenotype and a general over-expression of genes involved in fungal development were observed in the co-culture condition.

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