title: Diversity and chemotaxis of soil bacteria with antifungal activity against Fusarium wilt of banana.
abstract: The chemotactic response of bacteria to root exudates plays an important role in the colonization of bacteria in the rhizosphere. In this study, 420 strains of antifungal bacteria against Fusarium oxysporum f. sp. cubense (Foc) were screened for chemotaxis based on a cheA molecular diagnostic method. A total of 124 strains with antifungal efficiencies of 27.26-67.14 % generated a characteristic band of cheA. The chemotaxis of 97 bacterial strains producing a cheA band was confirmed using the drop assay and swarm plate assay using catechol, p-hydroxybenzoic acid, salicylic acid, and asparagine as the attractants. A phylogenetic analysis based on restriction fragment length polymorphisms (RFLPs) and 16S rDNA sequences indicated that the 124 chemotactic antagonists of Foc were affiliated with 18 species of Paenibacillaceae, Bacillaceae, Streptomycineae, Enterobacteriaceae, and Pseudomonadaceae. The chemical composition of banana root exudates were analyzed by GC-MS, and 62 compounds, including alkanes, alkenes, naphthalenes, benzenes, and alcohols, were evaluated. Five representative antagonists of Foc showed 1.76- to 7.75-fold higher chemotactic responses than the control to seven compounds in banana root exudates, as determination by capillary assays.
authors: Laboratory for Conservation and Utilization of Bio-Resources & Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, People's Republic of China.
authors: Ping
authors: P
authors: Li
authors: Li
authors: L
authors: Ma
authors: Yun Li
authors: YL
authors: Feng
authors: Ming He
authors: MH
authors: Mo
authors: Fa Xiang
authors: FX
authors: Yang
authors: Hao Fu
authors: HF
authors: Dai
authors: You Xing
authors: YX
authors: Zhao
mesh_terms: D000383:Agriculture; D000935:Antifungal Agents / Q000378:metabolism*; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002633:Chemotaxis / Q000502:physiology*; D005670:Fusarium / Q000145:classification / Q000502:physiology*; D005798:Genes, Bacterial / Q000235:genetics; D028521:Musa / Q000382:microbiology*; D010572:Pest Control, Biological; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D018517:Plant Roots / Q000737:chemistry / Q000382:microbiology; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S; D058441:Rhizosphere; D012988:Soil Microbiology
chemical_list: D000935:Antifungal Agents; D012336:RNA, Ribosomal, 16S