title: Molecular characterization and fumonisin production by Fusarium verticillioides isolated from corn grains of different geographic origins in Brazil.
abstract: Gibberella moniliformis is most commonly associated with maize worldwide and produces high levels of fumonisins, some of the most agriculturally important mycotoxins. Studies demonstrate that molecular methods can be helpful for a rapid identification of Fusarium species and their levels of toxin production. The purpose of this research was to apply molecular methods (AFLP, TEF-1α partial gene sequencing and PCR based on MAT alleles) for the identification of Fusarium species isolated from Brazilian corn and to verify if real time RT-PCR technique based on FUM1 and FUM19 genes is appropriated to estimate fumonisins B(1) and B(2) production levels. Among the isolated strains, 96 were identified as Fusarium verticillioides, and four as other Fusarium species. Concordant phylogenies were obtained by AFLP and TEF-1α sequencing, permitting the classification of the different species into distinct clades. Concerning MAT alleles, 70% of the F. verticillioides isolates carried the MAT-1 and 30% MAT-2. A significant correlation was observed between the expression of the genes and toxin production r = 0.95 and r = 0.79 (correlation of FUM1 with FB(1) and FB(2), respectively, P < 0.0001); r = 0.93 and r = 0.78 (correlation of FUM19 with FB(1) and FB(2), respectively, P < 0.0001). Molecular methods used in this study were found to be useful for the rapid identification of Fusarium species. The high and significant correlation between FUM1 and FUM19 expression and fumonisins production suggests that real time RT-PCR is suitable for studies considering the influence of abiotic and biotic factors on expression of these genes. This is the first report concerning the expression of fumonisin biosynthetic genes in Fusarium strains isolated from Brazilian agricultural commodity.
authors.affiliation: Department of Microbiology, Biomedical Institute II, University of São Paulo, Prof Lineu Prestes, 1374 Laboratory 249, São Paulo, Brazil. liliana_rocha@ymail.com
authors.forename: Liliana
authors.initials: L
authors.lastname: de Oliveira Rocha
authors.forename: Gabriela Martins
authors.initials: GM
authors.lastname: Reis
authors.forename: Valéria Nascimento
authors.initials: VN
authors.lastname: da Silva
authors.forename: Raquel
authors.initials: R
authors.lastname: Braghini
authors.forename: Marta Maria Geraldes
authors.initials: MM
authors.lastname: Teixeira
authors.forename: Benedito
authors.initials: B
authors.lastname: Corrêa
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis; D001938:Brazil; D004271:DNA, Fungal / Q000235:genetics; D037341:Fumonisins / Q000378:metabolism*; D005670:Fusarium / Q000235:genetics* / Q000302:isolation & purification* / Q000378:metabolism; D005800:Genes, Fungal; D005843:Geography; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D003313:Zea mays / Q000382:microbiology*
chemical_list: D004271:DNA, Fungal; D037341:Fumonisins; C056934:fumonisin B2; C056933:fumonisin B1