Research articleThe involvement of ROS producing aldehyde oxidase in plant response to Tombusvirus infection

- Tomato bushy stunt virus infection results in enhancement of aldehyde oxidase in leaves of N. benthamiana.
- Plants infected with TBSV exhibit significantly enhanced levels of AO2 and AO3 isoforms.
- The infection with virus resulted in boosted accumulation of hydrogen peroxide, compared to mock-inoculated plants.
- Elevated levels of H2O2 accumulation result in enhanced catalase activity in response to virus infection.

The influence of Tomato bushy stunt virus (TBSV) infection on the activity and isoformic composition of aldehyde oxidase and catalase in Nicotiana benthamiana plants was investigated. It was shown that the infection of plants with TBSV results in enhancement of leaf aldehyde oxidase (AO) isoforms AO2 and AO3. Significantly enhanced levels of superoxide radical producing activity of AO isoforms were also detected. This is the first demonstration of involvement of plant AO in defense mechanisms against viral infection. In addition, the infection caused an increased accumulation of hydrogen peroxide, compared to mock-inoculated plants. The virus infection resulted in increased activity of catalase (CAT) and superoxide dismutase (SOD) in roots and leaves of N. benthamiana. Moreover, activation of two additional CAT isoforms was observed in the leaves of plants after virus inoculation. Our findings indicate that the virus infection significantly affects enzymes responsible for the balance of ROS accumulation in plant tissue in response to pathogen attack.