Аннотация
The effect of long-term combined exposure to temperature stress and viral infection on the antioxidant defense system of Nicotiana benthamiana plants was studied in this work. It was shown that oxidative stress caused by the combined action of biotic and abiotic factors has an ambiguous effect on the development of the pathogen in the leaves of Nicotiana benthamiana plants. The article shows the heterogeneity of the impact of heat and cold stress and viral infection on the content of reactive oxygen species in the leaves of Nicotiana benthamiana plants. Thus, it was shown that low-temperature stress led to an increase in the level of accumulation of superoxide radical in plant leaves, while the effect of combined stress did not lead to a greater increase in the accumulation of superoxide radical. The combined effect of cold stress and viral infection led to an increase in the content of hydrogen peroxide, while there was reduced catalase activity. At the same time, a sharp increase in aldehyde oxidase activity was observed under temperature stress. The highest activity of the enzyme was observed under the combined effect of low temperature and viral infection. Thus, it can be assumed that oxidative stress in plant tissues leads to an increase in the level of accumulation of reactive oxygen species while affecting the enzymes responsible for the balance of accumulation of reactive oxygen species in plant tissue in response to a pathogen attack.