title: Buffet hypothesis for microbial nutrition at the rhizosphere.
abstract: An emphasis is made on the diversity of nutrients that rhizosphere bacteria may encounter derived from roots, soil, decaying organic matter, seeds, or the microbial community. This nutrient diversity may be considered analogous to a buffet and is contrasting to the hypothesis of oligotrophy at the rhizosphere. Different rhizosphere bacteria may have preferences for some substrates and this would allow a complex community to be established at the rhizosphere. To profit from diverse nutrients, root-associated bacteria should have large degrading capabilities and many transporters (seemingly inducible) that may be encoded in a significant proportion of the large genomes that root-associated bacteria have. Rhizosphere microbes may have a tendency to evolve toward generalists. We propose that many genes with unknown function may encode enzymes that participate in degrading diverse rhizosphere substrates. Knowledge of bacterial genes required for nutrition at the rhizosphere will help to make better use of bacteria as plant-growth promoters in agriculture.
authors.affiliation: Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México Cuernavaca, Mexico.
authors.forename: Martha G
authors.initials: MG
authors.lastname: López-Guerrero
authors.forename: Ernesto
authors.initials: E
authors.lastname: Ormeño-Orrillo
authors.forename: Mónica
authors.initials: M
authors.lastname: Rosenblueth
authors.forename: Julio
authors.initials: J
authors.lastname: Martinez-Romero
authors.forename: Esperanza
authors.initials: E
authors.lastname: Martïnez-Romero
keywords: bacterial genomes; rhizosphere; root exudates; soil microbiology; speciation