Structure of an Aspergillus flavus population from maize kernels in northern Italy

Infection with toxigenic and atoxigenic strains of Aspergillus flavus induces different transcriptional signatures in maize kernels

“…Atoxigenic A. flavus isolates were commonly deleted of a part or the entire aflatoxin gene cluster (Chang et al 2005). The atoxigenic isolate MUCL54911 belongs to the VCG IT6 that was observed most frequently in infected maize produced in Italy and showed the deletion of all 16 genes of the aflatoxin biosynthesis cluster (Mauro et al 2013). The inability to produce aflatoxins in kernels of the susceptible maize line at 96 hpi with the atoxigenic isolate MUCL54911 was confirmed in previous studies, where no aflatoxin production was detected in kernels at 7 days after inoculation with the same A. flavus strain (Mauro et al 2013(Mauro et al , 2015.…”

“…The atoxigenic isolate MUCL54911 belongs to the VCG IT6 that was observed most frequently in infected maize produced in Italy and showed the deletion of all 16 genes of the aflatoxin biosynthesis cluster (Mauro et al 2013). The inability to produce aflatoxins in kernels of the susceptible maize line at 96 hpi with the atoxigenic isolate MUCL54911 was confirmed in previous studies, where no aflatoxin production was detected in kernels at 7 days after inoculation with the same A. flavus strain (Mauro et al 2013(Mauro et al , 2015. Nevertheless, the absence of aflatoxin production for the atoxigenic strain did not change its growth ability on maize kernels, rather it increased in the later time-points compared to the toxigenic strain.…”

“…The isolates were previously examined for aflatoxin production and categorized into VCGs (Giorni et al 2007;Mauro et al 2013) and included in the culture collection of the Department of Sustainable Crop Production, Università Cattolica del Sacro Cuore, Piacenza, Italy. Cultures were inoculated on Petri plates (9 cm diameter) in Czapek Agar (CZ; sucrose 30 g; NaNO 3 2 g; KCl 0.5 g; MgSO 4 ·7H 2 O 0.5 g; FeSO 4 ·7H 2 O 0.01 g; K 2 HPO 4 1 g; ZnSO 4 ·7H 2 O 0.001 g; CuSO 4 ·7H 2 O 0.005 g; agar 15 g; H 2 O to 1 L) and incubated at 25°C with a 12 h photoperiod for 14 days.…”

High sequence variations in the region containing genes encoding a cellular morphogenesis protein and the repressor of sexual development help to reveal origins of Aspergillus oryzae

“…S-strain A. flavus isolates are very stable in aflatoxin production, but much less is known about their ability to produce CPA. A significant portion of L-strain A. flavus isolates collected from many parts of the world are nonaflatoxigenic (Horn and Dorner, 1999;Mauro et al, 2013;Perrone et al, 2014;Pildain et al, 2004;Wei et al, 2014). In contrast, nonaflatoxigenic S-strain isolates are rarely found (Orum et al, 1997).…”

“…Based on intactness and deletion size in the aflatoxin gene cluster commercial A. oryzae strains have been categorized into three groups (Kusumoto et al, 2000;Tao and Chung, 2014;Tominaga et al, 2006). Identical or similar deletion patterns have been widely reported for nonaflatoxigenic A. flavus isolates (Chang et al, 2005;Donner et al, 2010;Mauro et al, 2013;Wei et al, 2014;Yin et al, 2009). Deletions in these partial cluster strains are a recent occurrence and suggest gene loss .…”