The Aspergillus flavus fluP-Associated Polyketide Metabolite Promotes Production of Sclerotia

P-K. Chang1 , L. L. Scharfenstein1 , K. C. Ehrlich1 , J. D. Di Mavungu2

Author address: 

1Southern Regional Res. Ctr., Agricultural Res. Service, U. S. Dept. of Agriculture, New Orleans, LA, 2Faculty of Pharmaceutical Sci., Ghent Univ., Ghent, Belgium


Aspergillus flavus is able to produce a variety of polyketide-derived secondary metabolites, including the hepatocarcinogenic aflatoxin. The fungus reproduces and disseminates predominantly by production of conidia. It also produces sclerotia, which are hardened mycelia aggregates used to cope with unfavorable growth conditions. In the present study, we examined the role of the polyketide synthase gene, fluP, of secondary metabolite gene cluster 41 on fungal development by gene deletion and overexpression approaches. The fluP deletion strain grew and produced aflatoxin normally, but it produced a much lower amount of sclerotia than the wild type. In contrast, the fluP-overexpressing strain produced a higher amount of sclerotia than the wild type. When the fluP-overexpressing strain was co-cultured with the wild type and the deletion strain, it elevated their sclerotial production at edges of contact. Acetone extracts of the fluP-overexpressing strain but not of the deletion strain exhibited the same effect on promoting sclerotia production of the wild type. These results suggest that FluP polyketide synthase is involved in the synthesis of a diffusible metabolite that serves as a signal molecule to regulate sclerotial production

abstract No: 


Full conference title: 

ASM Microbe 2016
    • ASM microbe 1st (2016)