Ecology of bacterial endophytes in sustainable agriculture

Plants are the major source of carbohydrates for the heterotrophic microorganisms on Earth. For their growth, the latter organisms thus rely heavily on the efficient production of photoassimilates by plants. Plants even make use of diverse compounds to interact, and form associations, with often mutualistic beneficial bacteria. On the other hand, bacteria possess a wide range of metabolic properties that may modulate plant growth. Bacteria living inside plants, i.e. bacterial endophytes, might intimately interact with cells of the host, taking up secreted metabolites and releasing plant-growth-promoting compounds. This synergistic interaction has been recently demonstrated and exemplifies a so-called double-fitness trait which is active in the plant-endophyte partnership. The ecological role of bacterial endophytes that can improve sustainable agriculture is further discussed.