Insights into structural and physicochemical properties of maize starch after Fusarium verticillioides infection

Crop loss caused by toxigenic fungi is a standing problem for many cereals worldwide. In this study, structural and physicochemical changes of maize starch after F. verticillioides infection were evaluated. During the colonization, fungi use starch as the carbon source to provide nutrition for their growth and development resulting in the decline of the starch content of maize kernels. The maize starch was severely damaged and many holes were observed on the surface of starch granules when kernels were infected by F. verticillioides. Gel-permeation chromatography (GPC) analysis showed that amylopectin in maize starch was preferentially degraded and the content of amylose was increased. Simultaneously, the onset and peak of gelatinization temperatures of starch after fungal infection were raised. In comparison with native starch, the viscosity and setback value of infected starch was decreased. Furthermore, we found that 2 genes encoded by F. verticilllioides played important roles in starch degradation.