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Pseudomonas fluorescens2P24是分离自山东小麦全蚀病自然衰退土的1株生物防治菌株,产生抗生素2,4-二乙酰基间苯三酚(2,4-diacetylphloroglucinol;2,4-DAPG)是其主要防病机制。2,4-DAPG是由phlACBD基因簇合成,受多种调控因子调控。本研究用Tn5转座子插入技术,获得1株phlA基因转录增强的突变体,其突变基因为抗生素合成的负调控基因phlF。与野生菌相比,phlF基因的缺失突变体中phlA的转录增强约100倍,抗生素产量提高492倍。同时,菌株2P24的phlF缺失突变体对病原真菌的拮抗作用明显增强。但2,4-DAPG过量表达菌株对多种作物种子根生长有抑制作用。
Pseudomonas fluorescens 2P24 is a biocontrol strain isolated from naturally degraded soils of Shandong wheat eclipses and produces 2,4-diacetylphloroglucinol (2,4-DAPG) as its major anti-biotic Disease mechanism. 2,4-DAPG is synthesized by phlACBD gene cluster and regulated by many regulatory factors. In this study, Tn5 transposon insertion technique was used to obtain a mutant with phlA gene transcription enhancement. The mutant gene was phlF, a negative regulator of antibiotic synthesis. Compared with the wild-type strain, phlA deletion mutant phlA increased about 100-fold transcription, antibiotic production increased 492-fold. At the same time, the antagonistic effect of phlF deletion mutant of strain 2P24 on pathogenic fungi was significantly enhanced. However, 2,4-DAPG overexpression strains inhibited the growth of many crop seed roots.