Gene Discovery for Maize Responses to Nitrogen.

Nearly 10 million tons of N fertilizer are applied annually to the maize crop worldwide to increase grain yield.  Improving maize nitrogen use efficiency (NUE) will reduce input costs and the energy requirements for maize production, as well as reduce concerns about the environmental impacts of excess N fertilizer.  This project is applying the latest genomics resources to discover maize genes that are associated with NUE, defined as grain yield per unit of available N.   We have integrated RNA expression profiling, metabolite analyses, and QTL mapping approaches with agronomic evaluations of nitrogen response to identify molecular pathways and candidate genes that are associated with NUE. The information learned is now being applied to improving NUE in maize and other crops through breeding and biotechnology approaches.  Findings are also be applied to the improvement of NUE in tropical maize germplasm adapted to low soil fertility environments, through collaboration with the International Institute for Tropical Agriculture (IITA) in Nigeria.