【作者】 王磊；

【导师】 高锦明；

【作者基本信息】 西北农林科技大学 ， 植物学， 2009， 硕士

【摘要】 大量研究表明,内生菌能够产生与宿主相同或相似的活性成分。因此,植物内生菌的研究越来越被科学界关注。根瘤菌是作为内生菌群中的一部分,数个世纪以来人们对根瘤菌的研究多集中在豆科植物和根瘤菌的共生固氮方面,而对它的活性及化学成分研究较少。本文以一株分离自新疆巴楚县乌拉尔甘草的甘草根瘤菌N003为研究对象,对甘草根瘤菌发酵原液的化感活性、对真菌和细菌的抑制活性以及其次生代谢产物进行了研究。研究发现甘草根瘤菌N003的发酵液对苋菜和莴苣的萌发以及种子幼苗的生长有明显的抑制作用,并且明显的抑制小麦、油菜和莴苣幼根的生长。抑制真菌活性试验发现对马铃薯干腐菌、番茄早疫菌和玉米弯孢菌有抑制作用。研究还证明甘草根瘤菌N003的发酵液在发酵96h时各项活性最强,此时的根瘤菌处于生长旺期,各类代谢活动旺盛,产生的次生代谢产物多。试验利用硅胶柱层析、葡聚糖凝胶LH-20柱层析、RP-18柱层析等手段,从甘草根瘤菌N003发酵物中分离得到3个化合物L-1、L-2、L-3,并借助质谱(EI-MS, FAB-MS)、氢谱(1H-NMR)、碳谱(13C-NMR)等现代波谱技术,以及与标准化合物对照,确定化合物结构分别为麦角甾-4,6,8(14),22-四烯-3-酮(L-1)、过氧化麦角甾醇(L-2)、环(脯氨酸-酪氨酸)(L-3)。这3个化合物均为首次从甘草根瘤菌中分离得到。更多还原

【Abstract】 A large number of studies have shown that endophyte are able to produce the same or similar active ingredients with the host. Therefore, the research of endophyte is increasingly concerned by the scientific community. Rhizobium is part of the endogenous flora. Along several centuries, in terms of Rhizobium, emphasis has been laid on the studies of symbiosis and nitrogen fixation of leguminous plants and rhizoidal, while its activities and chemical compositions were less concerned.In order to understand the chemical constituents and bioactivity of second metabolites of Rhizobium, extraction of fermentation of rhizobia N003 were studied.Research indicates that the fermentation liquid of rhizobia N003 shows significant inhibition to the germination and the seeding’s growth of amaranth and lettuce. It also restrains the growth of the root of wheat radicle, rapeseed and lettuce. We also found its strong inhibition activity on Fusarium solani, Alternaria solani and Curvulavia lunata during the research of fungistasis. Research also indicates that the fermentation liquid of rhizobia N003, after 96h fermentation, shows strongest activities in all aspects. At that moment, the growth of Rhizobium is at its most vigorous and producing plenty of secondary metabolites.There are three compounds(L-1~L-3) isolated from Rhizobium for the first time, their structures were elucidated by means of spectroscopic methods including 2D NMR techniques and mass spectrometry, and combined with contrasting Standard compounds, to be ergosta-4,6,8(14),22-tetraen-3-one (L-1), 5α,8α-epidioxy-(22E,24R)-ergosta-6,22-dien-3β-ol (L-2), cyclo (Pro-Tyr)(L-3).更多还原