Phylogenetic analysis, fumonisin production and pathogenicity of Fusarium fujikuroi strains isolated from rice in the Philippines

Issue Date

9-2013

Abstract

BACKGROUND: Fusarium fujikuroi Nirenberg is a maize and rice pathogen causing important agricultural losses and produces fumonisins - mycotoxins which pose health risk to humans and farm animals. However, little information is available about the phylogenetics of this species and its ability to produce fumonisins in rice. We studied 32 strains isolated from rice in the Philippines and performed a phylogenetic analysis using the partial sequence of Elongation Factor 1 alpha (EF-1α) including isolates belonging to closely related species. Fumonisin B1 (FB1) production was analyzed in 7-day-old cultures grown in fumonisin-inducing medium by an enzyme-linked immunosorbent assay-based method and by real-time reverse transcriptase-polymerase chain reaction using primers for FUM1 gene, a key gene in fumonisin biosynthesis. RESULTS: Nucleotide diversities per site (π) were 0.00024±0.00022 (standard deviation) for the 32F. fujikuroi strains from the Philippines and 0.00189±0.00143 for all 34F. fujikuroi strains, respectively. F. fujikuroi isolates grouped into one cluster separated from the rest of isolates belonging to the closely related F. proliferatum and showed very low variability, irrespective of their geographic origin. The cluster containing strains of F. proliferatum showed higher intraspecific variability than F. fujikuroi. Thirteen of the 32 strains analyzed were FB1 producers (40.62%), with production ranging from 0.386 to 223.83ppm. All isolates analyzed showed FUM1 gene expression above 1 and higher than the CT value of the non-template control sample. Both seedling stunting and elongation were induced by the isolates in comparison with the control. CONCLUSION: F. fujikuroi are distinct from F. proliferatum isolates based on phytogenetic analysis and are potential fumonisin producers because all are positive for FUM1 gene expression. No relationship between fumonisin production and pathogenicity could be observed. © 2013 Society of Chemical Industry.

Source or Periodical Title

Journal of the Science of Food and Agriculture

ISSN

0022-5142

Volume

93

Issue

12

Page

3032-3039

Document Type

Article

Physical Description

illustrations, tables

Language

English

Subject

Bakanae disease, FUM1 expression, Fumonisin, Fusarium fujikuroi, Phylogenetics, Rice

Identifier

doi:10.1002/jsfa.6136.

Digital Copy

yes

Link to Full Text

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