Date of Award

8-2022

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Plant and Environmental Science

Committee Chair/Advisor

Richard Boyles

Committee Member

Sruthi Narayanan

Committee Member

Julia Kerrigan

Committee Member

Dil Thavarajah

Abstract

Fusarium causes widespread disease in crops resulting in yield and quality loss across a range of host taxa that results in global incidence of carcinogenic mycotoxins contaminating the world’s food systems. This research sought to crosscut frameworks developed across the Fusarium host crop species of wheat (Triticum aesitivum) and sorghum (Sorghum bicolor [L] Moench) to further understand mycotoxin suppression and resistance. A deeper understanding of the biochemical resistances available in sorghum grain mold (SGM) was built by following research of wheat based upon deoxynivalenol resistance to Fusarium head blight (FHB). Through this research, phenotyping methods for Fusarium damaged kernels (FDK) of wheat were evaluated to optimize DON prediction for grain samples. Also, untargeted metabolomics and novel SGM phenotyping methods were deployed to explore and characterize sorghum metabolic resistance to Fusarium grain mold. Results found in this research suggest three novel insights into Fusarium pathosystems of wheat and sorghum: (1) FDK phenotyping was improved through deployment of a novel imaging platform and exhibited an R2 of 0.76 with DON content in wheat suggesting efficient use of FDK as a proxy phenotype for DON phenotyping; (2) there is untapped potential in sorghum’s biochemical resistance mechanisms to Fusarium infection that can be exploited by following frameworks from FHB; (3) flavonoid metabolites of sorghum known to be responsive to disease do not provide adequate resistance over known constitutively produced defense-related metabolites such as phenols and phenolic acids, suggestive of hypersensitive response and programmed cell death being ineffective methods of resistance to SGM. Ultimately, utilizing concepts developed for host resistance to Fusarium infection in wheat provided a framework to study Fusarium infection in sorghum, driving increased understanding and characterization of host resistance to mycotoxin contamination.

Author ORCID Identifier

0000-0001-9249-6872

Available for download on Thursday, August 31, 2023

Share

COinS