| Institution: | 1. Phytopathology Laboratory, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
Unit for Environmental Sciences and Management, Faculty of Natural and Agricultural Sciences, North-West University, Potchefstroom, South Africa;2. NMR and Structure Analysis Unit, Department of Organic and Macromolecular Chemistry, Faculty of Science, Ghent University, Ghent, Belgium;3. Plant Pathology Unit, National Root Crops Research Institute (NRCRI), Umudike, Abia, Nigeria;4. Phytopathology Laboratory, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium;5. Department of Crop, Horticulture and Landscape Design, Faculty of Agricultural Sciences, Ekiti State University (EKSU), Ado-Ekiti, Nigeria;6. Microbial Processes and Interactions Unit, Faculty of Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium;7. Institute for Agricultural Research for Development (IRAD), Ekona, Cameroon;8. Research Group of Soil Fertility and Nutrient Management, Department of Environment, Ghent University, Ghent, Belgium |
| Abstract: | Pseudomonas isolates from tropical environments have been underexplored and may form an untapped reservoir of interesting secondary metabolites. In this study, we compared Pseudomonas and cyclic lipopeptide (CLP) diversity in the rhizosphere of a cocoyam root rot disease (CRRD) suppressive soil in Boteva, Cameroon with those from four conducive soils in Cameroon and Nigeria. Compared with other soils, Boteva andosols were characterized by high silt, organic matter, nitrogen and calcium. Besides, the cocoyam rhizosphere at Boteva was characterized by strains belonging mainly to the P. koreensis and P. putida (sub)groups, with representations in the P. fluorescens, P. chlororaphis, P. jessenii and P. asplenii (sub)groups. In contrast, P. putida isolates were prominent in conducive soils. Regarding CLP diversity, Boteva was characterized by strains producing 11 different CLP types with cocoyamide A producers, belonging to the P. koreensis group, being the most abundant. However, putisolvin III-V producers were the most dominant in the rhizosphere of conducive soils in both Cameroon and Nigeria. Furthermore, we elucidated the chemical structure of putisolvin derivatives—putisolvin III-V, and described its biosynthetic gene cluster. We show that high Pseudomonas and metabolic diversity may be driven by microbial competition, which likely contributes to soil suppressiveness to CRRD. |
