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ARS Home » Southeast Area » Tifton, Georgia » Crop Genetics and Breeding Research » Research » Publications at this Location » Publication #362722

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

Location: Crop Genetics and Breeding Research

Title: Genetic transformation to mitigate drought and aflatoxin-related losses in peanut

Author
item FOUNTAIN, J - University Of Georgia
item KEMERAIT, R - University Of Georgia
item CHU, Y - University Of Georgia
item OZIAS-AKINS, P - University Of Georgia
item CHEN, Z - Louisiana State University
item WANG, K - Iowa State University
item YANG, Y - Pennsylvania State University
item Guo, Baozhu

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

Interpretive Summary:

Technical Abstract: The mitigation of aflatoxin and drought stress related losses and food safety risks are priorities for the peanut research community. The development of novel technologies in combination with recent advances in peanut genomics allow for the deployment of genetic transformation and genome editing to address this issue. Previously, we have found that drought tolerance and aflatoxin resistance are correlated with reduced accumulation of reactive oxygen species (ROS) in peanut and corn. It was hypothesized that modifying the accumulation of antioxidant enzymes in these plants may result in reduced aflatoxin accumulation and increased drought tolerance. To test this hypothesis, we have used biolistic transformation to independently overexpress three antioxidant genes, AhAPX1, AhCAT1, and AhSOD1 in the cultivar Georgia Green. Conversely, we have engineered a novel polycistronic guide-RNA (gRNA) into the CRISPR-Cas9 cassette for genome editing to silence the expression of an isoform of AhCAT1. These approaches have resulted in the performance of six bombardments per construct/gene. Following regeneration and root induction, 27, 40, and 28 potentially transgenic T0 plants have been generated representing 9, 11, and 6 independent transgenic events for overexpression of AhAPX1, AhCAT1, and AhSOD1, respectively. Regeneration of CRISPR-Cas9 plants is currently in progress. Genotypic and phenotypic evaluation is currently underway with both PCR and enhanced green fluorescent protein (eGFP) expression. Using eGFP expression as an initial screen in young root and foliar tissues, 37.0%, 47.5%, and 42.9% of regenerated plants (43.2% overall) for AhAPX1, AhCAT1, and AhSOD1, respectively, showed positive eGFP expression. This may indicate that these overexpression constructs are inserted into expressible regions of the peanut genome and warrant further evaluation. Effects of these genome modifications on antioxidant gene expression and ROS accumulation will be discussed along with the potential effects on aflatoxin contamination and drought tolerance.