The Genomes of Endophytic Bacteria

Abstract

Genome sequencing and comparative genomics has had major impact on our understanding of the genetic potential, ecology, and evolution of microorganisms. The genomes of over a hundred bacterial endophytes have recently contributed insights into the molecular mechanisms that enable bacterial exploration of the plant interior, including genes for motility, colonization and synergistic interactions with the host. Known host-interaction systems include type IV pili, flagella, diverse dedicated secretion systems, genes for phytohormones synthesis and inhibition , bacterial volatiles, antimicrobials, and proteins with eukaryote-like domains, which may mimic host functions. Different endophytes use different sets of known host interaction systems, suggesting that there are multiple strategies to colonize and persist within plants. The majority of host-interaction systems are shared with other bacteria, including plant-and animal pathogens. Functional exploration of the large sets of endophyte genes encoding hypothetical proteins (especially those shared with other phytobacteria) promises to further elucidate endophytic adaptation to life in plant tissue, especially in regards to plant colonization, defense evasion and plant growth promotion.