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Title: Transcriptome analysis of Aspergillus flavus reveals isolate specific gene profiles in the response to oxidative stresses and carbon sources in vitro

Author
item FOUNTAIN, JAKE - University Of Georgia
item NAYAK, SPURTHI - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item PANDEY, MANISH - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item KUMAR, VINAY - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item BAJAJ, PRASAD - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item JAYALE, ASHWIN - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item CHITIKINENI, ANU - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item YANG, LIMING - University Of Georgia
item Scully, Brian
item LEE, DEWEY - University Of Georgia
item KEMERAIT, ROBERT - University Of Georgia
item VARSHNEY, RAJEEV - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item Guo, Baozhu

Submitted to: International Conference on Advances in Arachis through Genomics and Biotechnology
Publication Type: Abstract Only
Publication Acceptance Date: 10/15/2015
Publication Date: 11/4/2015
Citation: Fountain, J.C., Nayak, S.N., Pandey, M., Kumar, V., Bajaj, P., Jayale, A.S., Chitikineni, A., Yang, L., Scully, B.T., Lee, D., Kemerait, R.C., Varshney, R.K., Guo, B. 2015. Transcriptome analysis of Aspergillus flavus reveals isolate specific gene profiles in the response to oxidative stresses and carbon sources in vitro [abstract]. 8th International Conference on Advances in Arachis through Genomics and Biotechnology Meeting.

Interpretive Summary:

Technical Abstract: Aflatoxin contamination of peanut and maize is exacerbated by drought stress. Reactive oxygen species (ROS) are produced in host plants during drought/heat stress, and are hypothesized to stimulate aflatoxin production. In order to better understand why Aspergillus flavus produces aflatoxin and the role of aflatoxin in environmental oxidative stress responses, we examined the gene expression profiles of different A. flavus isolates (three toxigenic and three atoxgenic) under H2O2-derived oxidative stress in aflatoxin-conducive yeast extract sucrose (YES) and non-conducive yeast extract peptone (YEP) media. In total, 287.6 GB of data was generated with an average of 40.3x106 reads per sample using an Illumina HiSeq 2500 platform. Preliminary data analyses suggested that medium carbon source had the greatest effect on overall gene expression profiles likely due to altered carbon metabolic processes, developmental processes, and aflatoxin production. Based on gene expression clustering analysis, it was found that isolates which produced higher levels of aflatoxin and survived higher levels of H2O2 tended to exhibit fewer differentially expressed genes in response to increasing levels of stress than the other isolates, indicating a less vigorous response to H2O2-induced oxidative stress. In addition, mechanisms related to iron metabolism and other secondary metabolites were regulated along with antioxidant enzymes in response to increasing stress. This indicates that secondary metabolism and micronutrient availability also play important roles in oxidative stress responses in A. flavus. Continuing comparative analyses will examine the specific roles of aflatoxin in stress responses, and we hypothesize that ROS-mediated mechanisms potentially involved in crosstalk between stress signaling pathways and between host plants and the fungus will be revealed.