豇豆与锈菌互作中的活性氧代谢研究

Studies on the metabolism of active oxygen species during the interactions of cowpea and rust pathogen

本文分析了不同抗性水平的豇豆(Vigna sesquipdalis Wight)品种与锈菌(Uromyces vignae Barcl)互作中活性氧(ac-tive oxygen species,AOS)的发生、防御酶活性及膜脂过氧化水平的变化规律及其与豇豆抗锈病性的关系。结果表明,在接种后,免疫品种(益农)和感病品种(揭上和金迪)的超氧物歧化酶(superoxide dismutase,SOD)比活性均升高,且升高幅度都在12 h出现高峰;抗病品种(金山和特青)开始时降低,至12h时回升,在24 h(高抗)和48 h(中抗)出现高峰;在24 h时,免疫和抗病品种的SOD比活性高于感病品种。在接种后12 h内,免疫和抗病品种的过氧化氢酶(catalase,CAT)比活性都下降;而感病品种均上升,并在12 h出现第1个高峰。受锈菌侵染后,豇豆各品种都产生超氧阴离子(superoxide anion,O2-),在多数测试时段中,免疫和抗病品种的O2-产率净变化值低于感病品种。丙二醛(malondialdehyde,MDA)含量变化幅度与品种抗性呈负相关,与O2-产率的变化趋势基本相吻合。这些结果表明AOS代谢在豇豆与锈菌互作中起重要作用。

Relationships between regulations in the generation rates of active oxygen species (AOS), activities of defensive enzymes, levels of membrane lipid peroxidation and resistance of the cultivars during the interactions of cowpea (Vigna sesquipdalis Wight) and rust pathogen (Urornyces vignae Barcl) were analyzed. The results showed that superoxide dismutase (SOD) activity increased in immune and susceptible cultivars, and the peaks appeared at 12 hours after inoculation (a. i. ), but decreased at first and increased at 12 hours a. i. in resistant ones, the peaks appeared at 24 hours (in highly resistant one) and 48 hours a. i. (in moderately resistant one). At 24 hours a. i. , SOD activity in immune and resistant cultivars were higher than that in susceptible ones. Within 12 hours a. i. , the catalase (CAT) activities decreased in all immune and resistant cultivars, but increased in susceptible ones and the first increase peak appeared at 12 hours a. i. The results also showed that superoxide anion (O2-) generated in all cultivars infected with rust pathogen, and net change of O2- generation rates in immune and resistant cultivars were lower than that in susceptible ones at most determination stages. A negative relationship between net change in malondialdehyde (MDA) content and resistance was found, being basically in conformity with the tendency of change of O2- generation rate. These results indicated that metabolism of AOS played an important role in the interactions of cowpea and rust pathogen.