Gregory R OBrian

Works (10)

Updated: July 16th, 2023 21:15

2020 journal article

Aspergillus flavus Exploits Maize Kernels Using an "Orphan" Secondary Metabolite Cluster

INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES, 21(21).

By: L. Antiga*, S. La Starza*, C. Miccoli, S. D'Angeli *, V. Scala, M. Zaccaria *, X. Shu *, G. Obrian n ...

author keywords: Aspergillus flavus; maize kernel; salicylate hydroxylase; npp1; effectors; quercetin; histology
MeSH headings : Aflatoxins / genetics; Aflatoxins / metabolism; Aspergillosis / genetics; Aspergillosis / metabolism; Aspergillus flavus / genetics; Aspergillus flavus / pathogenicity; Aspergillus flavus / physiology; Catechols / metabolism; Crops, Agricultural / genetics; Crops, Agricultural / metabolism; Crops, Agricultural / microbiology; Disease Resistance / genetics; Gene Expression Regulation, Plant; Metabolic Networks and Pathways / genetics; Mixed Function Oxygenases / genetics; Mixed Function Oxygenases / metabolism; Multigene Family; Organisms, Genetically Modified; Plant Diseases / genetics; Plant Diseases / microbiology; Quercetin / metabolism; Salicylic Acid / metabolism; Seeds; Zea mays / genetics; Zea mays / metabolism; Zea mays / microbiology
TL;DR: Results suggest that the initial phase of fungal infection of the living tissues of maize kernels coincides with a significant increase ofFungal effectors such as SalOH and Npp1 that appear to be instrumental in eluding host defences and colonising the starch-enriched tissues, and therefore suggest a role of cluster 32 to the onset of infection. (via Semantic Scholar)
Source: Web Of Science
Added: November 30, 2020

2017 journal article

Carbon Dioxide Mediates the Response to Temperature and Water Activity Levels in Aspergillus flavus during Infection of Maize Kernels

TOXINS, 10(1).

By: M. Gilbert *, A. Medina *, B. Mack *, M. Lebar *, A. Rodriguez *, D. Bhatnagar*, N. Magan *, G. Obrian n, G. Payne n

author keywords: aflatoxin; Zea mays; climate change; secondary metabolites; RNA-seq
MeSH headings : Aflatoxin B1 / metabolism; Aspergillus flavus / genetics; Aspergillus flavus / metabolism; Carbon Dioxide; Edible Grain / microbiology; Plant Diseases; Temperature; Transcriptome; Water; Zea mays / microbiology
TL;DR: RNA sequencing data indicated that several genes, and in particular those involved in the biosynthesis of secondary metabolites, exhibit different responses to water availability or temperature stress depending on the atmospheric CO2 content, and two gene networks significantly influenced by changes in CO2 levels were identified. (via Semantic Scholar)
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UN Sustainable Development Goal Categories
6. Clean Water and Sanitation (OpenAlex)
Source: Web Of Science
Added: August 6, 2018

2013 journal article

Localization, morphology and transcriptional profile of Aspergillus flavus during seed colonization

MOLECULAR PLANT PATHOLOGY, 14(9), 898–909.

By: A. Dolezal n, G. Obrian n, D. Nielsen n , C. Woloshuk *, R. Boston n & G. Payne n

MeSH headings : Aspergillus flavus / genetics; Aspergillus flavus / growth & development; Aspergillus flavus / pathogenicity; Chromosomes, Fungal / genetics; Colony Count, Microbial; DNA, Fungal / isolation & purification; Electrophoresis, Agar Gel; Endosperm / microbiology; Gene Expression Profiling; Gene Expression Regulation, Fungal; Genes, Fungal / genetics; Humans; Seeds / cytology; Seeds / microbiology; Transcription Factors / metabolism; Transcription, Genetic; Zea mays / cytology; Zea mays / microbiology
TL;DR: Results from these studies indicate that A. flavus is capable of infecting all tissues of the immature kernel by 96 h after infection and will aid in the development of strategies aimed at preventing or slowing down A. flavus colonization of the maize kernel. (via Semantic Scholar)
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UN Sustainable Development Goal Categories
2. Zero Hunger (OpenAlex)
Sources: Web Of Science, NC State University Libraries
Added: August 6, 2018

2008 journal article

Quantification of urinary aflatoxin B-1 dialdehyde metabolites formed by aflatoxin aldehyde reductase using isotope dilution tandem mass spectrometry

CHEMICAL RESEARCH IN TOXICOLOGY, 21(3), 752–760.

By: D. Johnson n, P. Egner n, G. OBrian n, N. Glassbrook n, B. Roebuck n, T. Sutter  n, G. Payne n, T. Kensler  n, J. Groopman  n

MeSH headings : Aflatoxin B1 / urine; Aldehyde Reductase / metabolism; Aldehydes / metabolism; Animals; Carcinogens / metabolism; Chromatography, Affinity; Chromatography, High Pressure Liquid; Diet; Escherichia coli / metabolism; Glucuronidase / urine; Male; Radioisotope Dilution Technique; Rats; Rats, Sprague-Dawley; Reference Standards; Solid Phase Extraction; Spectrometry, Mass, Electrospray Ionization; Sulfatases / urine
TL;DR: This highly sensitive and specific isotope dilution method is applicable to in vivo quantification of urinary alcohol products produced by AFAR and contributes to the goal of mass balancing the fate of the bioreactive 8,9-epoxides of AFB 1 in vivo. (via Semantic Scholar)
Source: Web Of Science
Added: August 6, 2018

2007 journal article

Elucidation of veA-dependent genes associated with aflatoxin and sclerotial production in Aspergillus flavus by functional genomics

Applied Microbiology and Biotechnology, 76(5), 1107–1118.

By: J. Cary *, G. OBrian n, D. Nielsen n , W. Nierman*, P. Harris-Coward*, J. Yu*, D. Bhatnagar*, T. Cleveland *, G. Payne n, A. Calvo *

author keywords: Aspergillus flavus; veA; aflatoxin; sclerotia; microarray
MeSH headings : Aflatoxins / biosynthesis; Anthraquinones / metabolism; Aspergillus flavus / genetics; Aspergillus flavus / growth & development; Aspergillus flavus / metabolism; Fungal Proteins / genetics; Fungal Proteins / metabolism; Gene Expression Profiling; Gene Expression Regulation, Fungal; Gene Library; Genomics; Oligonucleotide Array Sequence Analysis / methods
TL;DR: Microarray technology was used to identify a subgroup of veA-dependent genes that exhibited time-dependent expression profiles similar to those of known aflatoxin biosynthetic genes or that were candidates for involvement in sclerotial production in the wild type. (via Semantic Scholar)
Sources: Web Of Science, Crossref, NC State University Libraries
Added: August 6, 2018

2007 article

Function and regulation of aflJ in the accumulation of aflatoxin early pathway intermediate in Aspergillus flavus

FOOD ADDITIVES AND CONTAMINANTS, Vol. 24, pp. 1043–1050.

By: W. Du n, G. Obrian n & G. Payne n

author keywords: aflatoxin; regulation
TL;DR: AflJ appears to modulate the regulation of early genes in aflatoxin biosynthesis and lead to an increase in early pathway intermediates. (via Semantic Scholar)
Source: Web Of Science
Added: August 6, 2018

2007 journal article

The effect of elevated temperature on gene transcription and aflatoxin biosynthesis

MYCOLOGIA, 99(2), 232–239.

By: G. OBrian n, D. Georgianna n, J. Wilkinson*, J. Yu *, H. Abbas *, D. Bhatnagar, T. Cleveland *, W. Nierman, G. Payne n

author keywords: AFLR; biosynthesis; micro-arrays
MeSH headings : Aflatoxins / biosynthesis; Aflatoxins / genetics; Aspergillus flavus / genetics; Aspergillus flavus / physiology; DNA-Binding Proteins / genetics; Fungal Proteins / genetics; Gene Expression Profiling; Gene Expression Regulation, Fungal; Hot Temperature; Polymerase Chain Reaction; Transcription Factors / genetics
TL;DR: Data indicate that the failure of A. flavus to produce aflatoxin at 37 C is not due to lack of transcription of aflR or aflS, and that AFLR is nonfunctional at high temperatures, suggesting that the factor(s) sensing the elevated temperatures must be acute. (via Semantic Scholar)
Source: Web Of Science
Added: August 6, 2018

2005 journal article

Aflatoxin production in peanut lines selected to represent a range of linoleic acid concentrations

JOURNAL OF FOOD PROTECTION, 68(1), 126–132.

By: H. Xue n, T. Isleib n, G. Payne n, W. Novitzky n & G. Obrian n

MeSH headings : Aflatoxins / analysis; Aflatoxins / biosynthesis; Arachis / genetics; Aspergillus flavus / growth & development; Aspergillus flavus / metabolism; Consumer Product Safety; Fatty Acids, Unsaturated / analysis; Fatty Acids, Unsaturated / pharmacology; Food Contamination / analysis; Food Microbiology; Genetic Variation; Humans; Linoleic Acid / analysis; Linoleic Acid / pharmacology; Peanut Oil; Plant Oils / chemistry; Predictive Value of Tests; Regression Analysis
TL;DR: Although fatty acid concentrations accounted for significant portions of genetic variation, it is not practical to use them as predictors for susceptibility to aflatoxin contamination, especially for lines in the normal range for oleate and linoleate. (via Semantic Scholar)
UN Sustainable Development Goals Color Wheel
UN Sustainable Development Goal Categories
2. Zero Hunger (OpenAlex)
Source: Web Of Science
Added: August 6, 2018

2003 journal article

Comparison of aflatoxin production in normal- and high-oleic backeross-derived peanut lines

PLANT DISEASE, 87(11), 1360–1365.

By: H. Xue*, T. Isleib*, G. Payne*, R. Wilson*, W. Novitzky* & . G O'Brian*

author keywords: Arachis hypogaea
TL;DR: Special care should be taken with high-oleic lines to prevent growth of Aspergillus spp. (via Semantic Scholar)
UN Sustainable Development Goals Color Wheel
UN Sustainable Development Goal Categories
2. Zero Hunger (OpenAlex)
Source: Web Of Science
Added: August 6, 2018

2003 journal article

Identification of genes differentially expressed during aflatoxin biosynthesis in Aspergillus flavus and Aspergillus parasiticus

FUNGAL GENETICS AND BIOLOGY, 39(2), 118–127.

By: G. OBrian n, A. Fakhoury n & G. Payne n

author keywords: aflatoxin; Aspergillus; ESTs; microarrays
MeSH headings : Aflatoxins / biosynthesis; Aflatoxins / genetics; Aspergillus / genetics; Aspergillus / metabolism; Aspergillus flavus / genetics; Aspergillus flavus / metabolism; DNA, Complementary / analysis; DNA, Fungal / analysis; Expressed Sequence Tags; Gene Deletion; Gene Expression Profiling; Genes, Fungal; Molecular Sequence Data; Oligonucleotide Array Sequence Analysis; RNA, Fungal / genetics; RNA, Messenger / analysis
TL;DR: Gene expression analysis of Aspergillus parasiticus grown under conditions conducive and non-conductive for aflatoxin production was evaluated using glass slide microarrays containing the 753 ESTs and no predicted function could be ascribed to 18 of the 24 genes whose elevated expression was associated with a flatoxin biosynthesis. (via Semantic Scholar)
Source: Web Of Science
Added: August 6, 2018

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