Genome sequence and comparative analyses of atoxigenic Aspergillus flavus WRRL 1519
Guohua Yin1,2, Sui Sheng T Hua3, Kayla K Pennerman1
1a Department of Plant Biology, Rutgers , The State University of New Jersey , New Brunswick , New Jersey 08901.
Mycologia
|July 4, 2018
Summary
A nonaflatoxigenic Aspergillus flavus strain WRRL 1519 was sequenced, revealing genetic deletions in aflatoxin and cyclopiazonic acid synthesis pathways. This strain shows promise as a biocontrol agent for reducing mycotoxin contamination in crops.
Area of Science:
- Mycology
- Food Safety
- Agricultural Biotechnology
Background:
- Aflatoxins, produced by Aspergillus flavus, are carcinogenic mycotoxins contaminating food and feed, posing health risks.
- Nonaflatoxigenic A. flavus strains are used as biocontrol agents to reduce aflatoxin contamination in crops like corn and peanuts.
Purpose of the Study:
- To sequence and analyze the genome and transcriptome of the atoxigenic A. flavus strain WRRL 1519.
- To genetically characterize WRRL 1519 and compare it with aflatoxigenic and other nonaflatoxigenic A. flavus strains.
- To evaluate WRRL 1519's potential as a biocontrol agent for mycotoxin reduction in nut crops.
Main Methods:
- Whole-genome and transcriptome sequencing of A. flavus strain WRRL 1519.
- Bioinformatic analysis to compare genetic makeup with other A. flavus strains.
- Identification of gene deletions and sequence similarities in mycotoxin synthesis gene clusters.
Main Results:
- Strain WRRL 1519 shares high genomic similarity with other A. flavus strains (38.0 Mb size, 47.2% GC content, 46 secondary metabolite clusters).
- Significant deletions and low sequence identity were found in genes essential for aflatoxin and cyclopiazonic acid (CPA) synthesis.
- Key genes for infectivity appear to be maintained, suggesting good crop colonization potential.
Conclusions:
- The atoxigenic A. flavus strain WRRL 1519 lacks essential genes for aflatoxin and CPA production due to genetic deletions.
- WRRL 1519 retains genes important for infectivity, making it a strong candidate for biocontrol.
- This strain can be a valuable tool for managing aflatoxin and CPA contamination in high-value nut crops.
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