Jeongdae Im
To address the mitigation challenge, the team will engineer novel plant species (e.g., new corn cultivars by cross cultivation and genetic modification) that will produce secondary metabolites called biological nitrification inhibitor (BNI) that in turn will provide a pathway to suppress GHG emission.
Agricultural soil management is the largest contributor to N2O emissions, comprising 74% of the total emissions in the US and 60%–80% globally. For these reasons, there have been many attempts to repress nitrification in agriculture. Nitrification inhibitors have been studied since the mid-1950s, and hundreds of synthetic nitrification inhibitors (SNIs) have been developed.
However, these artificially synthesized inhibitors are not widely applied in practice because (a) their biological stability is limited, (b) some of these artificial SNIs have limited usability because they are toxic and adversely affect beneficial soil microorganisms, and (c) in general, artificially synthesized nitrification inhibitors are expensive. Alternatively, many studies have reported that certain secondary metabolites in the tissues of diverse plant species, including trees, grasses, and mosses, may inhibit soil nitrification activity, as shown by higher NH4 + concentrations and smaller nitrifier community sizes. With the advent of novel technologies, in particular the development of a bioluminescent, recombinant strain of Nitrosomonas europaea, it was finally confirmed that certain plants could suppress soil-nitrification by releasing inhibitors from roots, termed biological nitrification inhibitor (BNI). In this project, Im's group in collaboration with Kim's group will develop a novel approach on BNIs. The BNIs have emerged as a promising new area of research not only because of its potential to improve nitrogen use efficiency in cropping systems but also for its implications for sustainable agricultural soil management, i.e., reduced N2O emissions.