Skip to main content
ARS Home » Northeast Area » Frederick, Maryland » Foreign Disease-Weed Science Research » Research » Publications at this Location » Publication #361310

Research Project: Molecular Identification, Characterization, and Biology of Foreign and Emerging Viral and Bacterial Plant Pathogens

Location: Foreign Disease-Weed Science Research

Title: Discovery of tunicamycin-related biosynthetic gene clusters in three Rathayibacter species, including one endemic to the Northwest U.S. (R. agropyri)

item Tancos, Matthew
item Sechler, Aaron
item DAVIS, II, EDWARD - Oregon State University
item CHANG, JEFF - Oregon State University
item SCHROEDER, BRENDA - University Of Idaho
item MURRAY, TIMOTHY - Washington State University
item Rogers, Elizabeth

Submitted to: APS Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 6/4/2019
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Rathayibacter toxicus, an APHIS-listed Select Agent, produces a neurotoxigenic glycolipid similar to tunicamycin. Endemic to Australia, R. toxicus is obligately vectored by Anguinid seed gall nematodes to the developing seedheads of forage grasses, where tunicamycin is synthesized and subsequently consumed by foraging livestock. This results in the only known naturally occurring tunicamycin-associated disease, annual ryegrass toxicity of livestock. To investigate whether a tunicamycin-related biosynthetic gene cluster (TGC) was present in other Rathayibacter, all available genome sequences were analyzed. Novel TGCs were identified in R. agropyri, R. iranicus, and the undescribed South African Rathayibacter species “EV”. The putative TGCs shared conserved tunicamycin-related genes essential for toxin production, but differ in gene order, orientation, and number. All tested R. toxicus, R. agropyri, R. iranicus, and R. EV strains possess a putative TGC. Therefore, all three species appear to be capable of synthesizing tunicamycin-like toxins; although it remains to be determined whether and under what conditions toxin is actually produced. Exploration of tunicamycin sensitivity and genetic variation within the TGC of each species is ongoing. The identification of multiple TGCs highlights the conserved nature of tunicamycin-like antibiotics within the Rathayibacter genus.