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SESSION 2: SECONDARY METABOLITES – BIOCHEMISTRY,
BIOSYNTHESIS, FEED AND FOOD SAFETY
P29 - Different levels of fumonisin production and
FUM gene cluster expression on 2B710Hx corn hybrid
G. M. Reis 1 , L. O. Rocha 1 , V. M. Barroso 1 , L. J. Andrade 1 , B. Corrêa 1
1 University of São Paulo, Biomedical Sciences Institute, Avenue Professor Lineu Prestes, 1374, São
Paulo-Brazil
E-mail: gabrielamreis@usp.br
Maize is the third most cultivated crop worldwide, and Brazil is currently, the
fourth largest producer in the world. Fusarium verticillioides is commonly
associated with maize and it is capable to produce high levels of fumonisins.
Studies regarding the use of transgenic corn have shown that fumonisin
contamination could be reduced due to the damage decrease caused by insects
on grains. The aim of this study was to evaluate the effect of cry 1F toxin
produced by Bacillus thuringiensis subsp. aizawai, expressed in the 2B710Hx
(Herculex) corn hybrid on the fumonisin production and on FUM gene expression
by F. verticillioides ICB 13BA (NCBI accession number; GU 989110). 2B710 Hx
corn samples and its respective isogenic non-Bt were previously irradiated with 20
kGy in order to eliminate fungi contaminants from field. Plates were inoculated
with 5 x 10 8 spores/mL and incubated at 25 o C and Aw of 0.99. After 10, 20 and
30 days, samples were analysed regarding FB1 and FB2 contamination and
FUM1, FUM3, FUM6, FUM7, FUM8, FUM10, FUM11, FUM13, FUM14, FUM15,
FUM17, FUM18, FUM19 and FUM21 gene expression. The statistical analyses
were performed using the softwares R 2.9, Gamlss package and SAS 9.1. The
results showed reduced fumonisin B1 contamination on 2B710 Hx during the 30
days of analyses (p< 0.005). Regarding FB2, there was no statistical difference
between the isogenic and transgenic hybrids. There was no correlation between
FUM gene cluster and fumonisin production according to Pearson’s correlation
test (except for FUM19, p