链霉菌702对水稻的防病潜能和防病机制

发布时间：2018-04-03 08:33

  本文选题：链霉菌702　切入点：农抗702　出处：《江西农业大学》2013年博士论文

【摘要】：链霉菌702是江西农业大学应用微生物实验室从土壤中分离筛选到的具有独立知识产权的一株链霉菌,其所产抗真菌组分农抗702经结构鉴定为多烯大环内酯类新结构化合物。本论文主要以水稻纹枯病菌为供试病原菌,从细胞、亚细胞、生理生化、分子生物学等方面研究了农抗702的抑菌机理及防病促生机制,主要研究结果如下：农抗702为淡黄色粉末状物质,熔点170-173.5℃,旋光度为[α]D23.7=+4.3425.(c =1.09 in MeOH),紫外光谱表明在318 nm,303 nm,290nm处有三个典型吸收峰,符合多烯类抗生素图谱特征；红外光谱表明其含有C=O、C=C、C-O、OH和CH2。农抗702对热较稳定,温度超过60℃活性开始下降；在强酸强碱条件下活性不稳定,pH 5-6时活性稳定。研究农抗702对病菌菌丝生长、菌核形成和萌发、孢子萌发的抑制作用,借助电镜观察其对菌丝超显微形态和结构的影响。结果表明,农抗702对病菌菌丝生长抑制作用明显,处理菌丝干瘪和皱缩,细胞膜轮廓不清、破损,细胞器严重损伤,空泡化。农抗702明显抑制病菌菌核的形成、萌发和孢子的萌发。通过农抗702作用后的水稻纹枯病菌相对电导率增加72.2%,蛋白质、核酸、Mg2+、K+离子等胞内物质均发生了不同程度的渗漏；麦角甾醇含量降低了92.0%,细胞膜的结构不完整；清除脂质过氧化物、自由基的能力下降。随着农抗702浓度的提高,病菌的侵染因子羧甲基纤维素酶、多聚半乳糖醛酸酶、果胶甲基半乳糖醛酸酶的活性均有不同程度下降。农抗702处理水稻叶片后,明显提高水稻抗纹枯病作用。农抗702处理水稻秧苗,稻苗体内的过氧化物酶,多酚氧化酶、苯丙氨酸解氨酶、过氧化氢酶等防御酶酶活性较高,对超氧化物歧化酶无显著的影响。农抗702处理水稻叶片后,叶片中的p-1,3葡聚糖酶活显著提高,上调的蛋白质点数较多,蛋白质点表达丰度差异显著。低浓度农抗702促进水稻种子萌发、胚根和芽的生长,根系活力提高,但含糖量下降。种子中的淀粉酶活性、蛋白质含量随农抗702浓度的升高先升后降。施加链霉菌702菌剂后土壤细菌和霉菌数量均有所减少,放线菌数量增加,降低了硝化细菌和亚硝化细菌的菌数,提高了好气性纤维素分解菌菌数,而土壤微生物不同生理类群的变化,加速了土壤养分循环,增强了水稻的养分吸收,从而促进水稻生长。综上所述,结合多烯大环内酯类抗生素对真菌的作用机理,初步推断农抗702对病原真菌的抑菌机理是：农抗702穿过细胞壁,与真菌细胞膜上的麦角甾醇相互结合形成麦角甾醇—抗生素复合物,增加菌体细胞膜的渗透性,进而使酶活性降低,供能不足,抑制菌体呼吸代谢、能量代谢,最终导致病原真菌的细胞膜破损,细胞器严重损伤,生长发育受到抑制,菌丝形态严重变形,直到死亡。另外,农抗702能够诱导水稻产生抗性酶,促进种子的萌发。土壤配施链霉菌702提高了秧苗素质,促进有益微生物的生长,抑制有害微生物的生长。
[Abstract]:The 702 is Streptomyces isolated and screened with independent intellectual property rights of a strain from the soil of Jiangxi Agricultural University applied microbiology laboratory, the production of antifungal components of agricultural antibiotic 702 by structure identified as new compounds of polyene macrolide. This thesis mainly with Rhizoctonia solani as tested pathogens from the cells. Subcellular, physiological and biochemical, molecular biology and other aspects of the antibacterial mechanism of agricultural antibiotic 702 and preventing diseases and promoting growth mechanism, the main results are as follows: agricultural antibiotic 702 is light yellow powder like material, the melting point of 170-173.5 Deg. C, rotation [alpha (C =1.09]D23.7 =+4.3425. in MeOH), UV Vis spectra showed that at 318 nm. 303 nm 290nm, there are three typical absorption peaks, with polyene antibiotic spectrum; infrared spectra showed that it contains C=O, C=C, C-O, OH and CH2. Nongkang 702 stable for heat, the temperature above 60 DEG C activity began to decline in the strong acid; Under the condition of alkali activity is not stable, stable activity at pH 5-6. The research of agricultural growth of 702 anti mycelium, sclerotium formation and germination, inhibition of spore germination, electron microscope observation of the effect of micro morphology and structure of mycelia with. The results showed that the agricultural antibiotic 702 on mycelial growth inhibition and treatment of dry mycelium and cell membrane shrinkage, unclear contour, damaged organelles, serious injury, vacuolization. Formation of agricultural antibiotic 702 significantly inhibited the germination of Sclerotinia sclerotiorum, germination and spore. The agricultural antibiotic 702 after rhizoctoniasolani relative conductivity increased by 72.2%, protein, nucleic acid, Mg2+, K+ ions are intracellular substances leaking in different degrees; ergosterol content was reduced by 92%, the cell membrane structure is not complete; eliminating lipid peroxide, decreased ability of free radicals. With the increase of the concentration of agricultural antibiotic 702, bacteria infection factor Suo Jiaji Cellulase, polygalacturonase, pectin methyl galacturonate activity of all enzymes decreased in different degrees. The agricultural antibiotic 702 rice leaves after treatment, significantly improve the effect of rice sheath blight. The agricultural antibiotic 702 processing of rice seedling in rice seedlings, peroxidase, polyphenol oxidase, phenylalanine ammonia lyase, peroxidase and other defense enzymes high activity, no significant effect on superoxide dismutase. Nongkang 702 rice leaves after treatment, significantly improve the living p-1,3 glucanase in leaves, up-regulated protein spots more protein spots expressed significant difference. The low concentration of agricultural antibiotic 702 promote seed germination, radicle and shoot growth, root vigor improve, but sugar content decreased. The seeds of amylase activity, protein content increased with concentration of agricultural antibiotic 702 and then decreased. The number of soil bacteria and fungi were less applied Streptomyces 702 agent Less, the number of actinomycetes increased, reducing the number of bacteria nitrifying bacteria and denitrifying bacteria, improve aerobic cellulose decomposing bacteria number and soil microbial physiological groups change, accelerated soil nutrient cycling, enhance rice nutrient absorption, so as to promote the growth of rice. In summary, combined with the mechanism of polyene macrolide antibiotics on fungi, antibacterial mechanism preliminarily concluded the agricultural antibiotic 702 against pathogenic fungi is: agricultural antibiotic 702 through the cell wall, ergosterol and fungal cell membrane on ergosterol: antibiotic combine to form complexes, the increase of permeability of cell membrane, the enzyme activity decreased, energy supply shortage suppression bacterial respiratory metabolism, energy metabolism, resulting in damaged cell membrane of pathogenic fungi, organelles serious damage, growth inhibited the mycelial morphology severely deformed, until death. In addition, the agricultural antibiotic 702 can It is enough to induce rice to produce resistant enzymes and promote seed germination. Soil mixed Streptomyces 702 improves seedling quality, promotes beneficial microorganism growth and inhibits harmful microorganism growth.

【学位授予单位】：江西农业大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：S435.11;S476
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本文编号：1704427