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ARS Home » Midwest Area » St. Paul, Minnesota » Plant Science Research » Research » Publications at this Location » Publication #403659

Research Project: Genetic Improvement and Cropping Systems of Alfalfa for Livestock Utilization, Environmental Protection and Soil Health

Location: Plant Science Research

Title: Global expression analysis of Bipolaris oryzae genes in cultivated wild rice leaves during early stages of colonization

item CASTELL-MILLER, CLAUDIA - University Of Minnesota
item RANJAN, ASHISH - University Of Minnesota
item KONO, TOM - University Of Minnesota
item Samac, Deborah - Debby
item KIMBALL, JENNIFER - University Of Minnesota

Submitted to: American Phytopathological Society
Publication Type: Abstract Only
Publication Acceptance Date: 8/12/2023
Publication Date: 8/16/2023
Citation: Castell-Miller, C., Ranjan, A., Kono, T.J., Samac, D.A., Kimball, J. 2023. Global expression analysis of Bipolaris oryzae genes in cultivated wild rice leaves during early stages of colonization. Plant Health 2023. August 12-16, 2023. Denver, Colorado.

Interpretive Summary:

Technical Abstract: The ascomycete Bipolaris oryzae (Breda de Haan) Shoemaker (Cochliobolus miyabeanus [S. Ito & Kurib.] Drechsler ex Dastur) causes fungal brown spot (FBS) in wild rice (Zizania palustris), which often limits grain production in cultivated wild rice (CWR). An RNA-seq study conducted at 24h and 48h of the fungus grown in-planta versus in-vitro found an increasing number of differentially expressed genes (DEGs) over time. Gene ontology terms enriched in DEGs were associated with pathogenesis, toxins, and oxidative stress. Variance partitioning analysis showed that the largest source of variation was the individual (median = 60.5%), followed by an interaction between treatment and time (median = 0.00065%). Some genes with strong treatment-by-time effects had biological functions related to pathogenesis, toxins, transport and terpenoid biosynthesis. Within DEGs, at least 85 peptides were identified as putative effectors predicted to be localized in the plant apoplast, cytoplasm, or with dual localization. A few effectors had biological annotations corresponding to an intracellular protein with a LysM domain, a trypsin, and hydrolytic and lipolytic enzymes. Additional DEGs included putative carboxy-and metallo-peptidase, polyketide synthetase, non-ribosomal peptide synthase, and putative isocitrate lyase functions. This study suggests a fungal temporal gene expression that includes many potential virulence factors toward the host. It increases insight into the B. oryzae-CWR interaction and opens future research on fungal gene silencing to better understand this pathosystem.