Undergraduate Honors Thesis Projects

Date of Award


Document Type

Honors Paper

Degree Name

Equine Pre-Veterinary/Pre-Graduate Studies-BS


Equine Science


Jennifer Bennett, Ph.D.

First Committee Member

John Tansey, Ph.D.

Second Committee Member

Michele Acker, Ph.D.


Streptomyces scabies, Common Scab, Potato Pathogen, c-di-GMP

Subject Categories

Agriculture | Genetics


Streptomyces scabies is a bacterial plant pathogen responsible for a condition known as common scab in potatoes and other tuber crops. Aerial hyphae and spore development have been shown to be regulated by cyclic di-GMP (c-di-GMP) signaling in the non-pathogenic species Streptomyces coelicolor and Streptomyces venezuelae. The second messenger c-di-GMP is ubiquitous among bacteria and is connected to many functions such as: motility, virulence, and biofilm formation, but the effects of c-di-GMP signaling in other streptomycetes are unknown. The purpose of this study is to elucidate the function of the suspected S. scabies c-di-GMP phosphodiesterase genes SCAB11501 and SCAB27241 through the construction of deletion mutants. The effects these genes have on morphology, development, and virulence are of particular interest in this study. Successful S. scabies deletion mutants for SCAB27241 have been evaluated macro- and microscopically for differences in morphology between the mutants and wild type. Potato infection assays were performed in order to compare the mutant’s pathogenicity to that of the wild type. These phosphodiesterase genes may represent targets for antimicrobial agents that combat S. scabies infection and that of other related, prevalent agricultural pests.

Available for download on Sunday, April 20, 2025