Overproduction of reactive oxygen species involved in the pathogenicity of Fusarium in potato tubers

• We firstly elucidated the role of ROS in Fusarium–potato interaction.
• Fusarium sulphureum led larger lesion diameters and caused higher MDA content.
• F. sulphureum caused an earlier and a higher level of ROS production.
• Overproduced ROS acted as a toxic agent of pathogenicity.

Differences in virulence between Fusarium sulphureum and Fusarium sambucinum were compared. Changes in reactive oxygen species production and metabolism in inoculated slices of potato tubers were also compared. The result showed that Fusarium infection induced significant production of ROS, lipid peroxidation and loss of cell membrane integrity, but low activity of superoxide dismutase (SOD) and ascorbate peroxidase (APX). Compared to F. sambucinum, F. sulphureum   led larger lesion diameters on potato tubers and slices. It resulted in more superoxide anion (O2-) and earlier peak of hydrogen peroxide (H2O2), but lower activity of catalase (CAT) and APX, and accompanied with higher malondialdehyde (MDA) content and lower cell membrane integrity. These findings suggested that overproduction of ROS involved in the pathogenicity of Fusarium in potato tubers.