Semester of Graduation
Spring 2026
Degree Type
Thesis
Degree Name
Masters in Integrative Biology
Department
Department of Molecular and Cellular Biology
Committee Chair/First Advisor
Dr. Premila Achar
Second Advisor
Dr. Soon Goo Lee
Third Advisor
Dr. Sigurdur Greipsson
Abstract
Aflatoxin contamination caused by Aspergillus flavus remains a challenge to peanut production, food safety, and public health. Among aflatoxins, Aflatoxin B1 (AFB1) is one of the most toxic occurring mycotoxins and is recognized as a potent carcinogen, mutagen, and hepatotoxin. Peanut producing states in the United States continue to experience economic losses due to Aspergillus infestation. To control fungal contamination during pre-harvest, post-harvest, and storage stages and synthetic fungicides are applied. This study aimed to develop modified Georgia peanut plants expressing the proteins Chitinase and β-1,3-Glucanase and to evaluate effectiveness in reducing AFB1 accumulation. Agrobacterium-mediated transformation was performed using plasmid constructs pCAMBAR Chi 11 and pCAMBAR Glu 289 containing chitinase and β-1,3-glucanase genes, followed by embryogenesis and regeneration in the Georgia-12Y peanut cultivar. Transgene integration was confirmed through polymerase chain reaction (PCR). Protein expression was evaluated using sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE), Western blot analysis, β-glucuronidase (GUS) assay, and a colorimetric chitinase assay. AFB1 quantification was performed using liquid chromatography–mass spectrometry (LC–MS). PCR and sequencing confirmed successful gene integration, with Chitinase amplified at 600 bp and Glucanase at 700 bp. Western blot detected β-1,3-glucanase expression at 12 kDa, while GUS and chitinase assays confirmed enzymatic activity in GM plants. LC–MS analysis demonstrated lower AFB1 intensities in GM plants compared to controls (U = 0, n₁ = n₂ = 3, p = 0.025, one-tailed). This study highlights the potential of genetic engineering for improving peanut resistance against A. flavus and enhancing food safety, sustainability, and protection.
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