【作者】 邢卓；

【导师】 王关林；

【作者基本信息】 辽宁师范大学 ， 植物学， 2005， 硕士

【摘要】 研究了蜂毒肽对17 种致病菌和农作物病原菌的抑菌谱及其抑菌机理,并测定了蜂毒肽对农作物生理指标及防御系统酶活性的影响。结果表明:蜂毒肽抑菌谱广,对革兰氏阳性和革兰氏阴性致病菌及多种农作物病原细菌都有抑制作用,对农作物病原真菌的孢子和菌丝体的生长也有抑制作用。抑菌曲线表明蜂毒肽快速毒杀菌体;SDS-PAGE 表明在蜂毒肽作用下,白菜软腐病菌菌体内的蛋白表达并没有特异性的变化;透射电镜观察,蜂毒肽作用下白菜软腐菌的菌体表面上出现孔洞,菌体裂解;扫描电镜观察,蜂毒肽对白菜软腐病菌的菌体表面结构造成破坏,在菌体细胞膜上打孔,使菌体皱缩裂解。投射和扫描电镜观察蜂毒肽作用番茄叶霉病菌孢子,发现菌体细胞质固缩,质壁分离,菌体变形以至死亡,但在细胞表面未见有孔洞出现,说明蜂毒肽对真核生物和原核生物的抑菌作用是不同的。实验还发现蜂毒肽对农作物生理指标的影响具有普遍性,低浓度的蜂毒肽对细胞中的叶绿素、可溶性糖、核酸及蛋白质含量均有一定促进作用,高浓度时有抑制作用,但影响都很微弱(t 检验p>0.05)。蜂毒肽对植物防御系统酶具有诱导效应,玉米POD 同工酶的研究进一步表明蜂毒肽对其有明显影响:而且对不同品种玉米POD 酶的作用不尽相同,表现了品种间的特异性。更多还原

【Abstract】 The antimicrobial spectrum and antimicrobial mechanism of melittin on nearly 20 species pathogen were studied, and the effects of melittin on the physiological indices of crops and the defensive enzymes of maize at growth stage were mensurated systematically. The results showed: melittin can inhibite the activity of Grampositive, Gram-negtive bacteria, several species pathogen bacteria and pathogen fungi of crops , which indicated that melittin had wide inhibition spectrum. The inhibiting curve showed the capacity of melittin killing pathogens quickly; SDS-PAGE made it clear that there was no secific change to the protein expressing in Erwinia carotowora subsp.carotovora with the effect of melittin, and the result proved melittin inhibiting the activity of pathogens was not through acting on the proteins expressing and effecting metabolizition. Observation under scanning electronmicroscope revealed that the surface of structure of Erwinia carotowora subsp.carotovora was destructed with several holes by melittin. Those holes result in leakage of contents of bacterium. Observation under transmission electron microscope also revealed that. The results above indicated; the inhibiting mechanism of melittin on pathogen of crops was that the cell membranes and the cell walls of the bacterium were made holes which resulted in the breach of cell membranes,then the leakage of contents in the cells, at last dead. Observation under scanning and transmission electron microscope were also made to Fulvia fulva ---a sort of fungus, that revealed cytoplasm concentrated,cell membrane separated from cell wall,while cell membrane was not broken down into a cavity, the phenomenon showed the inhibiting mechanism of melittin on prokaryota and eukaryota was different.It was found that the effects of melittin on the four cultivars of crops was similar----the content levels of chlorophyll, soluble sugar, nucleic acid and protein were promoted by the low concentration(5 mg/L), and inhibited by the higher (50 mg/L), although the effects were not significant(t-test, p>0.05). Melittin can induce the activity of the defensive enzyme of crops: PAL and PPO reached the maximal levels 48 hours after spraying the solution of melittin (5 mg/L), which were led to increase of 178% and 9.8% respectively compared to the control; SOD was increased by 31.5% after 6 hours. The activity of POD reach the maximal levels at the concentration 50mg/L.The study of POD isoenzyme of maize elucidated further that melittin influenced the defensive enzymes: induction to some zymogram band (P11)while inhibition to other zymogram,, and the effect were not uniform to the different cultivars of maize, which showed the particularity of cultivars.更多还原