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ARS Home » Southeast Area » Tifton, Georgia » Crop Genetics and Breeding Research » Research » Publications at this Location » Publication #361812

Research Project: Improvement of Genetic Resistance to Multiple Biotic and Abiotic Stresses in Peanut

Location: Crop Genetics and Breeding Research

Title: Dissecting the role of oxidative stress in host-Aspergillus flavus interactions using genomics and genetic engineering

item FOUNTAIN, JAKE - University Of Georgia
item CLEVENGER, J - M & M Mars Company - United States
item Vaughn, Justin
item CHU, Y - University Of Georgia
item STARR, D - Louisiana State University
item YOUNGBLOOD, RAMEY - Collaborator
item KORANI, W - University Of Georgia
item PANDEY, M - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item CHEN, Z - Louisiana State University
item WANG, K - Iowa State University
item YANG, Y - Pennsylvania State University
item KEMERAIT, R - University Of Georgia
item Scheffler, Brian
item OZIAS-AKINS, P - University Of Georgia
item Guo, Baozhu

Submitted to: American Phytopathological Society
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2019
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Dissecting the connection between drought stress and aflatoxin contamination in maize and peanut has led to the observation that drought tolerant, aflatoxin contamination-resistant plants tend to accumulate less reactive oxygen species (ROS) in their tissues under stress conditions. Oxidative stress also leads to exacerbated aflatoxin production to varying degrees among diverse isolates of Aspergillus flavus. To take advantage of this observation and investigate this system as a potential avenue of mitigating aflatoxin contamination, a combination of genetic engineering and genomics has been employed. Genetic engineering approaches were done including transgenic overexpression and CRISPR-Cas9-mediated silencing for antioxidant genes in maize and peanut. Genotypic and phenotypic evaluation of effects on plant ROS accumulation, drought tolerance, and aflatoxin resistance is ongoing. In addition, to explore stress-linked mechanisms in A. flavus related to host resistance, a pair of reference genomes for A. flavus isolates with contrasting growth behavior, stress tolerance, and aflatoxin production were de novo assembled using Pacbio long-read sequencing and Bionano optical mapping. These represent the first pseudomolecule-level genomes produced for this important pathogen. Comparative analyses with other re-sequenced, diverse isolates as well as examining the effects of oxidative stress over time on early signaling events will also be discussed.