Author
Caitlin Henderson
chenderson033@gmail.com
Utah State University
Logan, UT
Coauthors
Dan Bean, Palisade Insectary, Colorado Dept. of Agriculture, Palisade, CO, USA
Robert Schaeffer, Utah State University, Logan, UT, USA
Chris Smith, Utah State University, Logan, UT, USA
Karen Rosen, Palisade, Colorado
Abstract
Cirsium arvense is a noxious weed invading many habitats worldwide. Once established, it rapidly spreads and displaces native and crop plants, reducing productivity and ecosystem function. Herbicide is the most common and effective control but has limitations, especially near waterways and remote areas. Biological control offers a sustainable alternative, with Puccinia punctiformis, an obligate rust fungus, gaining attention as a host-specific pathogen of C. arvense. Despite demonstrated effects on stem densities, variable success suggests abiotic and biotic factors influence pathogen infection and establishment. Using a culture-independent approach, we characterized microbiome diversity and composition on healthy and infected C. arvense leaves, as host–microbe and microbe–microbe interactions may affect pathogen success. Our results showed an overall increased richness and diversity in symptomatic plants compared to asymptomatic. Symptomatic plants bearing aeciospores harbour distinct fungal and bacterial communities, both epiphytic and endophytic. Several microbial taxa were significantly associated with disease state, spore type, and interaction. Notably, some microbes associated with the teliospore stage may enhance pathogen efficacy, while the distinct microbiome of symptomatic aeciospore plants suggests that aeciospores may serve as an alternative inoculum source. Further studies will assess microbe compatibility with P. punctiformis to improve C. arvense biocontrol.
keywords
Puccinia punctiformis
Cirsium arvense
teliospores
aeciospores
weed microbiomes
Highlights
C. arvense microbiome study includes bacteria, fungi, epi- and endophytes with rust association
Microbes significantly associated with symptomatic teliospore plants may increase inoculum efficacy
Symptomatic aeciospore plants have distinct microbe community suggesting alternative inoculum source