Antioxidant enzyme activities in maize plants colonized with Piriformospora indica

<jats:p>The bioprotection performance of<jats:italic>Piriformospora indica</jats:italic>against the root parasite<jats:italic>Fusarium verticillioides</jats:italic>was studied. We found that maize plants first grown with<jats:italic>F. verticillioides</jats:italic>and at day 10 inoculated with<jats:italic>P. indica</jats:italic>showed improvements in biomass, and root length and number as compared with plants grown with<jats:italic>F. verticillioides</jats:italic>alone. To validate our finding that inoculation with<jats:italic>P. indica</jats:italic>suppresses colonization by<jats:italic>F. verticillioides</jats:italic>, we performed PCR analyses using<jats:italic>P. indica</jats:italic>- and<jats:italic>F. verticillioides</jats:italic>-specific primers. Our results showed that inoculation with<jats:italic>P. indica</jats:italic>suppresses further colonization by<jats:italic>F. verticillioides</jats:italic>. We hypothesized that as the colonization by<jats:italic>P. indica</jats:italic>increases, the presence of/colonization by<jats:italic>F. verticillioides</jats:italic>decreases. In roots, catalase (CAT), glutathione reductase (GR), glutathione<jats:italic>S</jats:italic>-transferase (GST) and superoxide dismutase (SOD) activities were found to be higher in<jats:italic>F. verticillioides</jats:italic>-colonized plants than in non-colonized plants. Increased activity of antioxidant enzymes minimizes the chances of oxidative burst (excessive production of reactive oxygen species), and therefore<jats:italic>F. verticillioides</jats:italic>might be protected from the oxidative defence system during colonization. We also observed decreased antioxidant enzyme activities in plants first inoculated with<jats:italic>F. verticillioides</jats:italic>and at day 10 inoculated with<jats:italic>P. indica</jats:italic>as compared with plants inoculated with<jats:italic>F. verticillioides</jats:italic>alone. These decreased antioxidant enzyme activities due to the presence of<jats:italic>P. indica</jats:italic>help the plant to overcome the disease load of<jats:italic>F. verticillioides</jats:italic>. We propose that<jats:italic>P. indica</jats:italic>can be used as a bioprotection agent against the root parasite<jats:italic>F. verticillioides.</jats:italic></jats:p>