Gluconacetobacter diazotrophicus (syn. Acetobacter diazotrophicus), a promising diazotrophic endophyte in tropics

Endophytes are plant-associated prokaryotes that form association with their host plants by colonizing the internal tissues, which has made them valuable for agriculture as a tool in improving crop performance. Although the interaction between endophytes and host plants has not been fully understood, many bacterial species are reported to promote plant growth and the mechanism attributed includes nitrogen fixation, production of growth-promoting substances and increased resistance to pathogens and parasites. They have been reported from numerous plant species including sugarcane. Gluconacetobacter diazotrophicus (syn. Acetobacter diazotrophicus) - sugarcane association represents a model system for monocot-diazotrophic associations. This allows experimentation to answer questions pertaining to their establishment, colonization process, biological nitrogen fixation, growth promotion, etc. The main objective of this review is to summarize the recent works on this bacterium with special emphasis on its interaction with sugarcane. The topics being covered range from the sources of G. diazotrophicus, its classification and characteristics, genetic analysis, in planta colonization and detection, inoculation experiments with suggestions for future research.