高温对本氏烟抗病毒机制影响的研究

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

摘要:

为探究温度和植物抗性的相互作用,本研究对本氏烟（Nicotiana benthamiana, Nb）被芜菁花叶病毒（Turnip mosaic virus, TuMV）侵染后在不同温度下的表现进行实验,通过分子研究手段测定了温度对植物抗病毒能力的影响.结果显示,与常温(23°C)处理相比,病毒侵染在高温(30°C)处理下被抑制；且高温处理下水杨酸羟化酶（NahG）转基因烟草更显著.进一步检测表明,高温能够显著提高NahG烟草中抗氧化酶的活性.在侵染后期,高温促使染病植株中茉莉酸（Jasmonic acid, JA）相关基因表达显著上调.同时,RNA沉默相关基因的表达量在高温处理下的NahG烟草中均上调.上述结果表明,高温通过刺激RNA沉默及相关抗逆激素途径提高了植株对病毒的抗性.

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.