Development of an Arabidopsis thaliana-based bioassay for investigating seed colonization by mycotoxigenic Aspergillus species

• Published in: Plant pathology Vol. 56; no. 5; pp. 848 - 854
• Main Authors: Hammond, T.M, Tsitsigiannis, D.I, Keller, N.P
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01-10-2007; Blackwell Publishing Ltd; Blackwell
• Subjects: aflatoxin; aflatoxins; Arabidopsis; Arabidopsis thaliana; Aspergillus; Aspergillus flavus; Aspergillus nidulans; Aspergillus nidulellus; Aspergillus parasiticus; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; oxylipin-deficient mutant; Phytopathology. Animal pests. Plant and forest protection; sterigmatocystin; Plant pathology; Metabolite; Mycotoxin; Fungi; Arabidopsis thaliana; Signal transduction; Cruciferae; Aspergillus nidulans; Dicotyledones; Angiospermae; Development; Sterigmatocystin; Fungi Imperfecti; Species; Aflatoxin; Thallophyta; Aspergillus flavus; Bioassay; Biochemical compound; Oxylipin; Biological compound; Toxin; Aspergillus parasiticus; Spermatophyta; Mutation; Experimental plant; Colonization; oxylipin-deficient mutant
• ISSN: 0032-0862; 1365-3059
• DOI: 10.1111/j.1365-3059.2007.01644.x

Seeds of Arabidopsis thaliana are hosts for three mycotoxin-producing Aspergillus species, A. flavus, A. nidulans and A. parasiticus, enabling an Aspergillus-Arabidopsis infection (AAI) assay to be developed. The AAI assay involved inoculation of 10- to 12-mg aliquots of uniformly cultivated, surface-sterilized A. thaliana seeds in microcentrifuge tubes. Use of microcentrifuge tubes facilitated qualitative and quantitative analyses of post-infection characteristics such as sporulation and mycotoxin production. Cultivation of A. thaliana seeds under uniform environmental conditions is necessary to limit genotype-independent seed-lot variability. Using the A. nidulans oxylipin mutant, ΔppoABC, and two well-characterized A. thaliana pathogen-defence mutants, ein2-1 and pad4-1, the AAI assay permitted genetic analysis of seed infection and mycotoxin production. Sporulation, but not mycotoxin production, was impaired in A. nidulans ΔppoABC, while A. thaliana ein2-1 and pad4-1 had a small but detectable influence on A. nidulans sporulation that appeared to be dependent on seed age.