Lanubile A.,Catholic University of the Sacred Heart |
Logrieco A.,CNR Institute of Sciences of Food Production |
Battilani P.,Catholic University of the Sacred Heart |
Proctor R.H.,Bacterial Foodborne Pathogen and Mycology Research Unit |
Marocco A.,Catholic University of the Sacred Heart
Plant Science | Year: 2013
Fusarium verticillioides infects maize producing ear rot, yield loss and the accumulation of fumonisins. In the present study, a transcriptomic approach was employed to investigate the molecular aspects of the interaction of susceptible/resistant maize genotypes with fumonisin-producing/nonproducing strains of F. verticillioides over a time course of 4 days after inoculation. The fumonisin-nonproducing strain led transcription in susceptible maize kernels, starting from 48. h post inoculation, with a peak of differentially expressed genes at 72. h after inoculation. Pathogen attack altered the mRNA levels of approximately 1.0% of the total number of maize genes assayed, with 15% encoding proteins having potential functions in signal transduction mechanisms, and 9% in the category of transcription factors. These findings indicate that signalling and regulation pathways were prominent in the earlier phases of kernel colonization, inducing the following expression of defense genes. In the resistant maize genotype, the fum1 mutant of F. verticillioides, impaired in this polyketide synthase gene (PKS), provoked a delayed and weakened activation of defense and oxidative stress-related genes, compared to the wild-type strain. The inability to infect resistant kernels may be related to the lack of PKS activity and its association with the lipoxygenase pathway. Plant and fungal 9-lipoxygenases had greater expression after fum1 mutant inoculation, suggesting that PKS plays an indirect effect on pathogen colonization by interfering with the lipid mediated cross-talk between host and pathogen. © 2013 Elsevier Ireland Ltd.
Busman M.,Bacterial Foodborne Pathogen and Mycology Research Unit |
Butchko R.A.E.,Bacterial Foodborne Pathogen and Mycology Research Unit |
Proctor R.H.,Bacterial Foodborne Pathogen and Mycology Research Unit
Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment | Year: 2012
Bikaverin is a polyketide-derived pigment produced by multiple species of the fungus Fusarium, some of which can cause ear and kernel rot of maize. A method was developed for the analysis of bikaverin by high-performance liquid chromatography (LC) coupled to electrospray ionisation tandem mass spectrometry (MS/MS). The quantitative nature of the LC-MS/MS method was demonstrated over a range of concentrations of bikaverin in maize. For spike-recovery experiments utilising maize spiked with bikaverin to a level 5 μg g-1 of maize, the measured recovery (%) was 70.6 ± 10.4. Based on the utilised method, the limit of detection (based on a signal-to-noise ratio (S/N) > 3) was better than 0.5 μg g-1 from bikaverin spiked into uncontaminated ground maize. Further, the limit of quantitation (LOQ) was 3 μg g-1 (based on S/N > 10) from bikaverin spiked into ground maize. The method was applied to assess contamination of maize with bikaverin following inoculation of developing maize ears with Fusarium verticillioides under agricultural field conditions. © 2012 Copyright Taylor and Francis Group, LLC.