, and comparative genomic analyses of pv. strains of pepper ( var. ).

UNLABELLED

pv. () is an emerging phytopathogen that causes leaf spot (PLS) disease in pepper plants. can cause serious economic damage to pepper production, yet very little is known about the virulence factors carried by that cause disease in pepper seedlings. In this study, strains isolated from pepper plants showing PLS symptoms in Ohio between 2013 and 2021 ( = 16) showed varying degrees of virulence ( populations and disease symptoms on leaves) on 6-week-old pepper seedlings. studies assessing growth in nutrient-limited conditions, biofilm production, and motility also showed varying degrees of virulence, but and variation in virulence between strains did not correlate. Comparative whole-genome sequencing studies identified notable virulence genes including 30 biofilm genes, 87 motility genes, and 106 secretion system genes. Additionally, a total of 27 antimicrobial resistance genes were found. A multivariate correlation analysis and Scoary analysis based on variation in gene content ( = 812 variable genes) and single nucleotide polymorphisms within virulence genes identified no significant correlations with disease severity, likely due to our limited sample size. In summary, our study explored the virulence and antimicrobial gene content of in pepper seedlings as a first step toward understanding the virulence and pathogenicity of in pepper seedlings. Further studies with additional pepper strains will facilitate defining genes in that correlate with its virulence in pepper seedlings, which can facilitate the development of effective measures to control in pepper and other related pathovars.

IMPORTANCE

leaf spot (PLS) caused by pv. () causes significant losses to the pepper industry. Highly virulent strains under optimal environmental conditions (cool-moderate temperatures, high moisture) can cause severe necrotic lesions on pepper leaves that consequently can decrease pepper yield if the disease persists. Hence, it is important to understand the virulence mechanisms of to be able to effectively control PLS in peppers. In our study, , , and whole-genome sequence analyses were conducted to better understand the virulence and pathogenicity characteristics of strains in peppers. Our findings fill a knowledge gap regarding potential virulence and pathogenicity characteristics of in peppers, including virulence and antimicrobial gene content. Our study helps pave a path to further identify the role of specific virulence genes in causing disease in peppers, which can have implications in developing strategies to effectively control PLS in peppers.