茄子砧木根系苯丙烷类代谢与抗南方根结线虫水平的关系

The relationship between resistance to Meloidogyne incognita and phenylpropanes metabolism in roots of eggplant rootstock

采用盆栽幼苗人工接种方法,研究南方根结线虫侵染对茄子砧木幼苗根系苯丙氨酸解氨酶(PAL)、酪氨酸解氨酶(TAL)及多酚氧化酶(PPO)活性和总酚、木质素含量的影响。结果表明,无论是否遭受南方根结线虫侵染,幼苗根系PAL、TAL、PPO活性及总酚、木质素含量均以托鲁巴姆显著高于赤茄。虽然南方根结线虫侵染使2个茄子砧木幼苗根系苯丙烷类物质含量及相关酶活性均有所增加,但以托鲁巴姆增幅较大,其PAL、TAL、PPO活性及总酚、木质素含量的最大增幅较对照分别高67.87%、82.13%、32.19%、62.14%和20.91%,而赤茄仅分别较对照高47.13%、45.52%、18.08%、35.38%、14.86%。整个侵染进程中,托鲁巴姆始终表现出强烈的抗性反应,而赤茄除在初次侵染前期表现出一定的抗性反应外,其余时间反应较弱,尤其在遭受二次侵染时,抗性反应显著低于初次侵染。表明苯丙烷类代谢产物及关键酶与茄子砧木抗南方根结线虫水平密切相关。

In order to discuss the relationship between the resistance to Meloidogyne incognita and metabolism of phenylpropanes in roots of eggplant rootstock, effect of infection of Meloidogyne incognita on the activities of phenylalanine ammonia-lyse （PAL）, tyrosine ammonia-lyse （TAL） and polyphenoloxidase （PPO） and the contents of total phenolic compounds and lignin in seedling roots were studied with Solahum torvum, the high resistant variety and Solanum integrifolium, the susceptible variety, which were planted in pots and inoculated with Meloidogyne incognita. The results showed that whether the seedling roots were infected by Meloidogyne incognita or not, the activities of PAL, TAL and PPO and the content of total phenolic compounds and lignin in Solanum torvum were significantly higher than those in Solanum integrifolium. Though the contents of phenylpropanes and activities of relative enzyme in seedling roots of two different resistant varieties infected with Meloidogyne incognita both increased, the activities of PAL, TAL, PPO and contents of total phenolic compounds and lignin in Solanum torvum increased higher than those in Solanum integrifolium, and the highest increasing extension of those indexes in Solanum torvum was 67.87%, 82.13%, 32. 19%, 62.14%, 20. 91% higher than the control, but only 47. 13%, 45.52%, 18.08%, 35.38% , 14.86% higher than the control in Solanum integrifolium, respectively. During the process of infection, intensive resistant reaction was discovered in Solanum torvum, but the resistant reaction in Solanum integrifolium was weak except for at the earlier stage of first infection, especially, the resistance to second infection was remarkably lower than first infection. The results suggested that the metabolite of phenylpropanes and their key enzymes were closely related to resistance of eggplant rootstock to Meloidogyne incognita.