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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #316695

Research Project: Developing Genomic Approaches to Improve Resistance to Diseases and Aflatoxin Contamination in Peanut and Corn

Location: Crop Protection and Management Research

Title: Potential roles of environmental oxidative stress in aflatoxin production revealed in the Aspergillus flavus transcriptome

Author
item Fountain, J - University Of Georgia
item Yang, L - University Of Georgia
item Kemerait, R - University Of Georgia
item Nayak, S - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item Pandey, M - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item Kumar, V - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item Bajaj, P - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item Jayale, A - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item Chitikineni, A - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item Varshney, R - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item Lee, R - University Of Georgia
item Scully, Brian
item Guo, Baozhu

Submitted to: American Peanut Research and Education Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2015
Publication Date: 7/10/2015
Citation: Fountain, J.C., Yang, L., Kemerait, R.C., Nayak, S.N., Pandey, M., Kumar, V., Bajaj, P., Jayale, A.S., Chitikineni, A., Varshney, R.K., Lee, R.D., Scully, B.T., Guo, B. 2015. Potential roles of environmental oxidative stress in aflatoxin production revealed in the Aspergillus flavus transcriptome. Meeting Abstract. American Peanut Research and Education Society (APRES) meeting, July 14-16, 2015, Charleston, South Carolina.

Interpretive Summary:

Technical Abstract: Aflatoxin contamination caused by Aspergillus flavus infection in crops is known to be exacerbated primarily by abiotic stresses such as drought stress, and biotic stresses such as arthropod infestation. These stresses result in the production and accumulation of reactive oxygen species (ROS) in the host plant tissues which may function in signaling between A. flavus and the host plant, and is hypothesized to regulate aflatoxin production. To determine the specific mechanisms stimulated under oxidative stress in A. flavus and their relationship to aflatoxin production, we examined the complete transcriptomes of three toxigenic (AF13, NRRL3357, and Tox4) and three atoxigenic (Aflaguard, AF36, and K54) isolates that exhibit different degrees of oxidative stress tolerance. The isolates were cultured in aflatoxin conducive (yeast extract-sucrose; YES) and non-conducive (yeast extract-peptone; YEP) media supplemented with hydrogen peroxide ranging in concentration from 0 – 25mM. Total RNA was extracted and used in the construction of cDNA libraries for use in RNA sequencing. Initial quality assays were performed on an Illumina MiSeq platform resulting in the generation of ~2.1 x 106 reads per sample with an average read length of 74.45bp, and an average GC content of 52.21%. In total >70% of reads mapped to the A. flavus NRRL3357 reference genome (NCBI: AAIH00000000.2; Assembly: GCA_000006275.2, JCVI-afl1-v2.0). Whole transcriptome sequencing is underway using an Illumina HiSeq platform, and candidate genes responsible for the differences in isolate oxidative stress tolerance will be identified. These results may provide insights into the specific pathways regulated under oxidative stress, and the specific signaling molecules involved in promoting aflatoxin production in these isolates will be better understood allowing for focused efforts in resistance breeding efforts.