2026/01/13 by John Dobbs, Mee-Sook Kim, Ned B. Klopfenstein +1 · 1 voice
Biochemistry, Genetics and Molecular Biology · Agricultural and Biological Sciences · #Plant Pathogens and Fungal Diseases #Mycotoxins in Agriculture and Food #Plant-Microbe Interactions and Immunity
paper · doi:10.1094/phyto-07-25-0229-r
openalex publication_date 2026/01/13 · openalex created_date 2026/01/14 · openalex updated_date 2026/07/22
In this study, we used coniferous and non-coniferous hosts to assess the pathogenicity of a Fusarium annulatum isolate derived from southwestern white pine ( Pinus strobiformis), along with F. commune isolates derived from coniferous and herbaceous, non-conifer hosts. All isolates of both Fusarium spp. were found to be pathogenic to conifer hosts. For the tested non-coniferous hosts, F. commune isolates were found to be pathogenic to both rice and tomato, whereas F. annulatum was pathogenic to rice and potentially less aggressive on tomato. To investigate the molecular basis of pathogenicity, we identified differentially expressed pathogenicity-/virulence-associated genes by inoculating loblolly pine ( P. taeda) seedlings with isolates of conifer-derived F. commune (collected from ponderosa pine [ P. ponderosa]) and F. annulatum (collected from southwestern white pine), which were all previously confirmed to be pathogenic to loblolly pine in our assays. Seedlings were harvested at 12, 24, and 48 h postinoculation for transcriptomic analyses to identify pathogen genes associated with early infection of the host. Among the upregulated in planta (UIP) genes, we identified putative pathogenicity-/virulence-associated genes, including secreted effectors, secondary metabolite gene clusters involved in mycotoxin biosynthesis, and carbohydrate-active enzymes. To identify the putative conifer pathogenicity profiles of these potential conifer pathogens, we compared these UIP genes with the predicted proteomes of 17 conifer-associated Fusarium spp. isolates. These putative pathogenicity profiles did not definitively correspond with pathogenicity on coniferous versus herbaceous hosts but rather aligned with Fusarium species complexes. A subset of these shared UIP genes may aid in the development of detection methods for conifer-specific pathogens based on Fusarium species complexes. [Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 “No Rights Reserved” license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2026.