The research on the interaction between high temperature and viral defense mechanism in Nicotiana benthamiana

Abstract:

To explore the interaction between temperature as environmental factor and defense mechanism in the plant, we designed the experiment to research the action of Nicotiana benthamiana （Nb）infected Turnip mosaic virus （TuMV）under different temperature conditions, to analyze the effect of temperature to viral defense mechanism in the plant through a series of techniques of molecular biology. The analysis of Western blotting indicated that the infection of TuMV was reduced at a high temperature (30°C) compared with those under normal temperature (23°C) conditions. Moreover, salicylate hydroxylase (NahG)transgenic N. benthamiana plants exhibited higher resistance to TuMV at high temperatures than the wild type plants. Further experiments of enzymelinked immunosorbent assay showed higher activities for some antioxidant enzymes and higher reduced glutathione contents in the NahG plants at high temperature. The regulated jasmonic acid (JA) gene exhibited high expression under high temperature conditions at the late stage of infection. In addition, key components of the RNA silencing pathway were upregulated in the NahG plants. Taken together, these results indicated that high temperature had significant effects on plant resistance and improved the tolerance of N. benthamiana plants against TuMV infection via RNA silencing and related phytohormone pathways.