Abstract Detail

Host/Plant Pathogen Interactions and Plant Health Management

Errampalli, Deena [1].

Development of detection assays for toxic metabolites produced by fungi.

Biological control of soil-borne plant pathogens is a potential alternative to the use of chemical pesticides. Fungi are being developed as biological control of insect pests and plants diseases. The objective of this study was to develop a protocol to screen for mutagenic secondary metabolites produced by biocontrol fungi. In this experiment, insect biocontrol fungi Metarhizium anisopliae BIPESCO 5, Beauvaria bassiana ARSEF 5808 and Beauvaria brogniartii BIPESCO2, and plant disease biocontrols, Trichoderma harzianum JAT1977, Clonostachys rosea ACM941 were tested to determine if they produce any toxic secondary metaboloits. Two known toxin producing fungi, Aspergillus flavus and M. robertsii ARSEF 2575, and commercial toxin (AFB1) were used as positive controls. Concentrated extracts produced in liquid culture media by these biocontrol fungi were tested using TA98 and TA100 isolates of Salmonella typhimurium in the Ames MPF Penta I microplate format mutagenicity assay. In this study, an aflatoxin producing strain and a non toxin producers were compared for the production of mutagenic compounds, 4-nitroquinoline N-oxide (4-NQO), 2-aminoanthracene (2-AA) and 2-nitrofluorene (2-NF). The S. typhimurium TA98 detects 2-nitrofluorene (2-NF) and 2-AA while the S. typhimurium TA100 detects 4-NQO and 2-AA. The results from the Ames MPF Penta I assay showed that the positive control A. flavus produced two mutagenic metabolites, 4-NQO and 2-AA, while M. anisopliae BIPESCO 5 tested negative for 4-NQO and 2-AA. The negative result for the metabolite 2-NF using the S. typhimurium TA98 tester strain, indicates that the mutagen 2-NF was not produced by both Metarhizium isolates. All of the biocontrol fungi tested, in this study, failed to produce mutagenic secondary metabolites that can be detected by the sensitive MPF Penta assay, while, the low concentration of the metaboloites produced by the two toxin producers and the commercial toxin (AFB1) were detected by the assay. All the experiments were repeated at least once.

1 - Agriculture and Agri-Food Canada, 4902 Victoria Ave N, Vineland, Ontario, L0R2E0, Canada

Keywords:
biological control
Fungi
Trichoderma harzianum
Metarhizium anisopliae
Clonostachys rosea
Beauvaria brogniartii
Detection.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PPA026
Abstract ID:604
Candidate for Awards:None