"Bacteria in Agrobiology: Plant Probiotics" discusses the current trends and future prospects of beneficial microorganisms acting as Probiotics. Topics include the application for the aboveground fitness of plants, applications in mountain ecosystems, in tropical and Mediterranean forests, and in muga sericulture. Further aspects are Arabidopsis as a model system for the diversity and complexity of plant responses, plant parasitic nematodes, nitrogen fixation and phosphorus nutrition.