Influence of low-temperature stress on the production of zearalenone by three Fusarium species in vitro

Comparison and determination of ZEN production capacity of F. oxysporum, F. graminearum, and F. solani. The influence of low temperature stress and incubation time on the production of ZEN was also investigated. 

Research Method:

Production of ZEN was evaluated by incubating media cultures at a constant temperature of 25°C for a period of 14 days before being incubated at 8°C for 14 days (Low-temperature stress/ LTS). The second set of the samples was incubated at constant 25°C for 4 weeks’ time (constant- temperature/ CT). HPLC and a fluorescence detector were employed to measure the concentration of ZEN. The species-specific pair of primers was used to perform a PCR assay on the fungal DNA.

The higher levels of ZEN were seen at LTS compared with CT in three Fusarium species. The highest ZEN was produced in F. oxysporum media cultures. The significant production of ZEN was seen when F. oxysporum incubated at LTS compared with CT (P≤0.05). The highest and the lowest levels of ZEN were seen in F. oxysporum and F. solani and the difference of ZEN production by them were significant in CT and LTS, respectively (P≤0.05). ZEN production for the F. graminearum was in the intermediate level. Presence of PKS4 gene was confirmed by PCR in these Fusarium species. Limitations: Higher cost of ZEN detection by HPLC was a limitation. 

Originality/Value: 

Production of ZEN in LTS and CT by the Fusarium evaluated species was confirmed. However, LTS stimulate ZEN production in Fusarium media cultures, especially for F. oxysporum.