Author
FOUNTAIN, JAKE - University Of Georgia | |
YANG, L - University Of Georgia | |
KEMERAIT, R - University Of Georgia | |
BAJAJ, P - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India | |
PANDEY, M - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India | |
NAYAK, S - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India | |
JAYALE, A - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India | |
KUMAR, V - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India | |
CHITIKINENI, A - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India | |
VARSHNEY, R - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India | |
CHEN, S - University Of Florida | |
LEE, R - University Of Georgia | |
Scully, Brian | |
Guo, Baozhu |
Submitted to: American Peanut Research and Education Society Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 6/1/2016 Publication Date: 7/12/2016 Citation: Fountain, J.C., Yang, L., Kemerait, R.C., Bajaj, P., Pandey, M., Nayak, S.N., Jayale, A.S., Kumar, V., Chitikineni, A., Varshney, R.K., Chen, S., Lee, R.D., Scully, B.T., Guo, B. 2016. Gene expression profiles of Aspergillus flavus isolates responding to oxidative stress in different culture media [abstract]. American Peanut Research and Education Society Abstracts. Interpretive Summary: Technical Abstract: Aflatoxin contamination of peanut by Aspergillus flavus is exacerbated by drought stress. Drought also stimulates the production of reactive oxygen species (ROS) in plant tissues implying a correlation between ROS and aflatoxin production. Here, we performed gene expression analysis by RNAseq of toxigenic and atoxigenic isolates of A. flavus in aflatoxin conducive and non-conducive culture medium amended with various levels of H2O2. In total we generated 282.6 Gb of sequencing data with an average of 40.3 million filtered reads per sample of which 92.3% mapped to the A. flavus NRRL3357 genome. In general, isolates with greater oxidative stress tolerance and higher aflatoxin production exhibited fewer differentially expressed genes (DEGs) than less tolerant, atoxigenic isolates (r < -0.6). Genes involved in cell wall maintenance, antioxidant enzyme activity, cell membrane integrity, and carbon metabolism were regulated by increasing stress to different extents depending on medium carbon source. Fungal development pathways were also regulated in response to increasing stress more prevalently in less tolerant isolates indicating that delayed development may contribute to the overall differential expression patterns. Secondary metabolite production was also shown to be affected by oxidative stress and carbon source including aflatoxin and kojic acid. The expression of genes involved in aflatrem production were also regulated in a similar fashion to aflatoxin genes. Overall, these data suggest that the production of aflatoxin, aflatrem, and kojic acid are involved in A. flavus oxidative stress responses. |