The magic and menace of metagenomics: prospects for the study of plant growth-promoting rhizobacteria

This article aims to be a pragmatic primer into the field of metagenomics with special emphasis on the prospective contributions of metagenomics to the study of plant growth-promoting rhizobacteria (PGPR). After an introduction into the concepts and methodologies of metagenomics and a discussion of the numerous emerging variations on the basic theme, there will follow a short overview of the success stories in metagenomics (the ‘magic’ in the title of this review), a brief discussion about the technical problems and unrealistic expectations that are sometimes associated with metagenomics (the ‘menace’), and a shortlist of the lessons that can be learned by those that wish to explore the utility of metagenomics in the study of PGPR.