title: Organic acids from root exudates of banana help root colonization of PGPR strain Bacillus amyloliquefaciens NJN-6.
abstract: The successful colonization of plant growth promoting rhizobacteria (PGPR) in the rhizosphere is an initial and compulsory step in the protection of plants from soil-borne pathogens. Therefore, it is necessary to evaluate the role of root exudates in the colonization of PGPR. Banana root exudates were analyzed by high pressure liquid chromatography (HPLC) which revealed exudates contained several organic acids (OAs) including oxalic, malic and fumaric acid. The chemotactic response and biofilm formation of Bacillus amyloliquefaciens NJN-6 were investigated in response to OA's found in banana root exudates. Furthermore, the transcriptional levels of genes involved in biofilm formation, yqxM and epsD, were evaluated in response to OAs via quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Results suggested that root exudates containing the OAs both induced the chemotaxis and biofilm formation in NJN-6. In fact, the strongest chemotactic and biofilm response was found when 50 μM of OAs were applied. More specifically, malic acid showed the greatest chemotactic response whereas fumaric acid significantly induced biofilm formation by a 20.7-27.3% increase and therefore biofilm formation genes expression. The results showed banana root exudates, in particular the OAs released, play a crucial role in attracting and initiating PGPR colonization on the host roots.
authors: Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Ministry of Agriculture; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization; Nanjing Agricultural University, Nanjing, 210095, China.|Department of Horticulture and Landscape Architecture and Center for Rhizosphere Biology, Colorado State University, Fort Collins, Colorado 80523.
authors: Jun
authors: J
authors: Yuan
authors: Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Ministry of Agriculture; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization; Nanjing Agricultural University, Nanjing, 210095, China.
authors: Nan
authors: N
authors: Zhang
authors: Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Ministry of Agriculture; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization; Nanjing Agricultural University, Nanjing, 210095, China.
authors: Qiwei
authors: Q
authors: Huang
authors: Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Ministry of Agriculture; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization; Nanjing Agricultural University, Nanjing, 210095, China.
authors: Waseem
authors: W
authors: Raza
authors: Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Ministry of Agriculture; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization; Nanjing Agricultural University, Nanjing, 210095, China.
authors: Rong
authors: R
authors: Li
authors: Department of Horticulture and Landscape Architecture and Center for Rhizosphere Biology, Colorado State University, Fort Collins, Colorado 80523.
authors: Jorge M
authors: JM
authors: Vivanco
authors: Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Ministry of Agriculture; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization; Nanjing Agricultural University, Nanjing, 210095, China.
authors: Qirong
authors: Q
authors: Shen
mesh_terms: D001407:Bacillus / Q000187:drug effects / Q000254:growth & development* / Q000502:physiology; D018441:Biofilms / Q000187:drug effects; D002264:Carboxylic Acids / Q000494:pharmacology*; D002633:Chemotaxis / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D015169:Colony Count, Microbial; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D005798:Genes, Bacterial; D028521:Musa / Q000737:chemistry*; D053147:Plant Exudates / Q000737:chemistry*; D018517:Plant Roots / Q000382:microbiology*; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D002264:Carboxylic Acids; D053147:Plant Exudates