水杨酸和乙烯在烟草抗黑胫病中的作用

The role of salicylic acid and ethylene in resistance of tobacco to black shank

5 mmol/L水杨酸或1 g/L乙烯外源处理可诱导烟草对黑胫病的抗性,推迟植株死亡。不能积累水杨酸的转nabG基因植株和不表现乙烯应答反应的转etrl-1基因植株对黑胫病的抗性显著弱于野生型植株。组成性积累高水平水杨酸的转entC和pmsB基因植株对黑胫病的抗性明显强于野生型植株。这些结果说明水杨酸和乙烯增强烟草对黑胫病的抗性,减缓黑胫病的扩展。0.5 mmol/LKCN连续浇灌植株4天或浸渍叶片24h均不能恢复转nahG基因植株丧失的对黑胫病的抗病性。此结果进一步支持关于KCN处理不能恢复转nahG基因植株丧失的对真菌病害抗病性的假说。

Treatment of tobacco leaf with 5 mmol/L salicylic acid (SA) or 1 g/L ethylene induced resistance to black shank and delayed the death of infected plants. Resistance of plants transformed with nahG, which was unable to accumulate SA, or etrI-1 , which does not respond to ethylene, was significantly weaker than that of wild type plants. Resistance of plants transformed with entC and pmsB, which constitutively accumulate SA to a high level, was stronger than that of wild type plants. These results revealed that SA and ethylene enhanced resistance of tobacco to black shank and attenuated the spread of the pathogen. Treatments of continuous watering plant for 4d or soaking leaf for 24h with KCN did not restore the resistance lost in nahG transgenic plant. This result supported the hypothesis that KCN was not able to restore the resistance to fungal diseases lost in nahG transgenic plant.