Molecular characterization and fumonisin production by Fusarium verticillioides isolated from corn grains of different geographic origins in Brazil Liliana de Oliveira Rocha a, ⁎, Gabriela Martins Reis a , Valéria Nascimento da Silva a , Raquel Braghini a , Marta Maria Geraldes Teixeira b , Benedito Corrêa a a Department of Microbiology, Biomedical Institute II, University of São Paulo, Prof.Lineu Prestes, 1374,Laboratory 249, São Paulo, Brazil b Department of Parasitology, Biomedical Institute II, University of São Paulo, Prof.Lineu Prestes, 1374,Laboratory 107, São Paulo, Brazil a b s t r a c t a r t i c l e i n f o Article history: Received 19 May 2010 Received in revised form 5 October 2010 Accepted 3 November 2010 Keywords: Fusarium verticillioides Fumonisins Sequencing AFLP Real time RT-PCR Gibberella moniliformis is most commonly associated with maize worldwide and produces high levels of fumonisins,some of the most agriculturally importantmycotoxins.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 b 0.0001); r = 0.93 and r = 0.78 (correlation of FUM19 with FB 1 and FB 2 , respectively, P b 0.0001). Molecular methods used in this study were found to be useful for the rapid identi fication 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. © 2010 Elsevier B.V. All rights reserved. 1. Introduction Fumonisins are a group of mycotoxins discovered in 1988 in cultures of Fusarium verticillioides (syn. F. moniliforme, teleomorph Gibberella fujikuroi mating population A, or Gibberella moniliformis) isolated from corn in South Africa, which are associated with several mycotoxicosis (Bezuidenhoutet al., 1988; Gelderblom etal., 1988). Twenty-eight analogs have been described so far, including fumonisins B 1 (FB 1 ), B 2 (FB 2 ) and B 3 (FB 3 ) that are naturally produced. FB 1 is the most important toxins is related to the inhibition of sphingolipid mechanism, with serious consequences for the cell (Sweeley, 1991; Wang et al., 1991). Fumonisins cause mycotoxicosis in humans and animals, and FB 1 is classified as a group 2B carcinogen by the IARC (1993). In Brazil, studies regarding the occurrence of FB 1 and FB 2 in freshly harvested corn detected these mycotoxins in approximately 92% and 81% of samples, respectively, with average levels ranging from 0.02 to 79 μg/g for FB 1 and from 0.02 to 29 μg/g for FB 2 , these findings demonstrate the need for fumonisin control in corn grains from Brazil International Journal of Food Microbiology 145 (2011) 9–21 Contents lists available at ScienceDirect International Journal of Food Microbiology j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / i j f o o d m i c r o