Perneel M, Heyrman J, Adiobo A, De Maeyer K, Raaijmakers J M, De Vos P, Höfte M
Laboratory of Phytopathology, Department Crop Protection, Ghent University, Ghent, Belgium.
J Appl Microbiol. 2007 Oct;103(4):1007-20. doi: 10.1111/j.1365-2672.2007.03345.x.
To screen for novel antagonistic Pseudomonas strains producing both phenazines and biosurfactants that are as effective as Pseudomonas aeruginosa PNA1 in the biocontrol of cocoyam root rot caused by Pythium myriotylum.
Forty pseudomonads were isolated from the rhizosphere of healthy white and red cocoyam plants appearing in natural, heavily infested fields in Cameroon. In vitro tests demonstrated that Py. myriotylum antagonists could be retrieved from the red cocoyam rhizosphere. Except for one isolate, all antagonistic isolates produced phenazines. Results from whole-cell protein profiling showed that the antagonistic isolates are different from other isolated pseudomonads, while BOX-PCR revealed high genomic similarity among them. 16S rDNA sequencing of two representative strains within this group of antagonists confirmed their relatively low similarity with validly described Pseudomonas species. These antagonists are thus provisionally labelled as unidentified Pseudomonas strains. Among the antagonists, Pseudomonas CMR5c and CMR12a were selected because of their combined production of phenazines and biosurfactants. For strain CMR5c also, production of pyrrolnitrin and pyoluteorin was demonstrated. Both CMR5c and CMR12a showed excellent in vivo biocontrol activity against Py. myriotylum to a similar level as Ps. aeruginosa PNA1.
Pseudomonas CMR5c and CMR12a were identified as novel and promising biocontrol agents of Py. myriotylum on cocoyam, producing an arsenal of antagonistic metabolites.
Present study reports the identification of two newly isolated fluorescent Pseudomonas strains that can replace the opportunistic human pathogen Ps. aeruginosa PNA1 in the biocontrol of cocoyam root rot and could be taken into account for the suppression of many plant pathogens.
筛选能够产生吩嗪类化合物和生物表面活性剂的新型拮抗假单胞菌菌株，这些菌株在防治由瓜果腐霉引起的芋根腐病方面与铜绿假单胞菌PNA1具有同等效果。
从喀麦隆自然重度感染田地中健康的白芋和红芋植株根际分离出40株假单胞菌。体外试验表明，可从红芋根际获得瓜果腐霉的拮抗剂。除一株分离株外，所有拮抗分离株均产生吩嗪类化合物。全细胞蛋白质谱分析结果表明，拮抗分离株与其他分离的假单胞菌不同，而BOX-PCR显示它们之间具有高度的基因组相似性。对这组拮抗剂中两个代表性菌株进行的16S rDNA测序证实，它们与已有效描述的假单胞菌物种的相似性相对较低。因此，这些拮抗剂暂时标记为未鉴定的假单胞菌菌株。在这些拮抗剂中，假单胞菌CMR5c和CMR12a因其同时产生吩嗪类化合物和生物表面活性剂而被选中。对于菌株CMR5c，还证实了其吡咯菌素和藤黄绿菌素的产生。CMR5c和CMR12a对瓜果腐霉均表现出优异的体内生物防治活性，与铜绿假单胞菌PNA1的水平相似。
假单胞菌CMR5c和CMR12a被鉴定为防治芋上瓜果腐霉的新型且有前景的生物防治剂，它们能产生一系列拮抗代谢产物。
本研究报告了两种新分离的荧光假单胞菌菌株的鉴定，它们可在芋根腐病的生物防治中替代机会性人类病原体铜绿假单胞菌PNA1，并且可考虑用于抑制多种植物病原体。
