Publication Date

2025

Document Type

Dissertation/Thesis

First Advisor

Calvo, Ana M.

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Biological Sciences

Abstract

The present study aimed at elucidating the role of hdt5 in fungal morphology, mycotoxin production and in plant virulence in Aspergillus flavus. Currently, methodologies to prevent the negative impact of A. flavus are insufficient. It is known that expression of the hdt5 gene is dependent on hbx1, a master regulatory gene that affects expression of hundreds of genes in the A. flavus genome, controlling both development and secondary metabolism. However, while the aflatoxin gene cluster has been elucidated, the genetic regulatory mechanisms controlled by hdt5 are not fully understood. For this study, therefore, a complete strain set composed of a wild type, deletion mutant, and complementation strains were generated by fungal transformation. The study then utilized thin layer chromatography and liquid chromatography-mass spectrometry to determine differential levels of aflatoxin produced between strains. B73 corn line seeds were used as the model of plant infection. The study established that hdt5 is required for normal conidiation in A. flavus but is not necessary for sclerotial development. The study also found that hdt5 is indispensable for normal production of aflatoxin B1 and B2 but does not influence production of cyclopiazonic acid and aflatrem. Additionally, we found that hdt5 is not required for initial plant infection but contributes to A. flavus aflatoxin biosynthesis in plant tissue. This information has yielded invaluable information on a potential novel genetic strategy for biological competitive control of aflatoxigenic A. flavus.

Extent

75 pages

Language

en

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

Share

COinS