As a common plant disease, Fusarium head blight (FHB) is one of the devastating diseases on small grain cereal crops, which could significantly reduce grain quality and yield. FHB could also produce a variety of mycotoxins which are detrimental to livestock and pose a potential safety concern to human foods. Fusarium graminearum is the pathogen for FHB on wheat. The macroconidia formed by F. graminearum plays an important role in the dissemination of FHB. The conventional fungicidal methodsrely heavily on synthetic chemical pesticides. However, synthetic chemical pesticides are usually hazardous to animals and the environmentdue to their residual toxicity. Furthermore, fungi have developed resistance to some traditional fungicides, such as benzimidazoles and dicarboximides, which makes it more difficult to control fungal growth. Thus, alternative antifungal approaches need to be developed, which should overcome the fungicide resistance for a better fungicidal effect while posing no harmful effect on the environment. It would be even better if it could also decompose mycotoxins produced by fungi.As an environmentally friendly alternative to the commonly used chemical fugicides, a highly effective photocatalytic disinfection of F. graminearum macroconidia under visible light illumination was demonstrated on a visible-light-activated palladium-modified nitrogen-doped titanium oxide (TiON/PdO) nanoparticle photocatalyst. Because of the opposite surface charges of the TiON/PdO nanoparticles and the F. graminearum macroconidium, the nanoparticles were strongly adsorbed onto the macroconidium surface, which is beneficial to the photocatalytic disinfection of these macroconidia. The photocatalytic disinfection mechanism of TiON/PdO nanoparticles on these macroconidia could be attributed to their cell wall/membrane damage caused by the attack from ROSs as demonstrated by the fluorescence/phase contrast microscopy observations, while a breakage of their cell structure was not necessary for their loss of viability.

Antifungal activity and mechanism of palladium-modified nitrogen-doped titanium oxide nanoparticle photocatalyst on agricultural pathogenic fungi Fusarium graminearum

248th National Meeting (2014)

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