Engineering the rhizosphere: Expressing a bias

The rhizosphere is a largely unexplored frontier for genetic engineering. Processes in the rhizosphere influence plant disease, plant nutrition and root architecture by affecting the dynamics of microbial populations and communities. There is interest in engineering plants to manipulate the rhizosphere for numerous reasons. Such plants might resist soilborne pathogens more effectively, be better hosts to beneficial microorganisms, remediate toxic waste, or attract communities of soil microorganisms that enhance plant health. Central among the strategies to engineer the rhizosphere is the effort to create a 'biased rhizosphere', which involves engineering plants to secrete nutrients that specifically enhance the growth of desirable microorganisms.