叶霉菌粗毒素对番茄幼苗防御酶及活性氧的诱导

以番茄不同抗性品种的幼苗为材料,采用浸渍法研究了低浓度的叶霉菌粗毒素对番茄叶片防御酶(SOD 、POD 、PAL)活性及活性氧(O_2~-和H_2O_2)的诱导作用,为探讨病菌毒素诱导植物抗病性的生理生化机制提供科学依据.结果表明,番茄经叶霉菌粗毒素诱导后,抗、感品种叶片的SOD活性下降,但抗病品种的下降比率小,且比感病品种具有较高的酶活性;抗、感品种的POD活性变化趋势均为先上升后下降,二者间的酶活性变化差异不大; 抗、感品种PAL活性均升高,但抗病品种增加更快,且增加比率高于感病品种;抗、感品种的O_2~-产率和H_2O_2含量的变化呈增加趋势,抗病品种的增加比率均高于感病品种,且增加峰值出现早.说明叶霉菌粗毒素诱导的番茄体内防御酶和活性氧变化与番茄抗叶霉病有着密切的关系.

Induce of Crude Toxin from Cladosporium fulvum on Defense Enzyme and Activity Oxygen of Tomato Seedlings

The inducement of crude toxin from Cladosporium fulvum on defense enzyme (SOD,POD,PAL) and activity (O_2~-,H_2O_2) was studied in leaves of different tomato varieties by soaking method. The studies provided scientific basis on plant physiological and biochemical resistance mechanisms induced by pathogen-toxin. The results showed that superoxide dismutase (SOD) activity of all varieties descended,but the resistant variety had lower declining ratio and higher enzyme activity than that of the susceptible one. Changes of peroxidase (POD) activity in two varieties were similar. POD activity increased at first,followed by a decline,but two varieties had a little diversity in activity change.Phenylalanine ammonia-lyase (PAL) activity increased in two varieties,but PAL activity in the resistant variety increased fast,and increasing ratio was higher than that in susceptible one. Production rate of superoxide anion (O_2~-) and hydrogen peroxide (H_2O_2) content increased. Increasing ratio in resistant variety was higher than that in susceptible one. The activity in the resistant variety appeared earlier than that in the susceptible one. Changes of defense enzyme and activity oxygen induced by toxin from Cladosporium fulvum in tomato seedlings were closely related to their resistance.