BIOLOGICAL NITROGEN FIXATION IN THE MUCILAGE OF MAIZE AERIAL ROOTS

The primary goal of this project is to gain a better understanding of the environmental factors, the genes and the molecular mechanisms controlling aerial root development, mucilage production and nitrogen fixation in the mucilage produced by aerial roots of specific corn landraces. To accomplish this, we will determine the genetic basis of this trait, determine how aerial roots produce this mucilage, how nitrogen fixed by the bacteria is transferred to the plant, and if we can improve this system using inoculation with natural or engineered bacteria.The specific objectives of this proposal are to:Determine the environmental factors affecting aerial root development and mucilage production using greenhouse experiments to determine the environmental factors affecting aerial root development and mucilage production.Identify the genetic determinants of aerial root development, mucilage production, and associative nitrogen fixation. We will use double haploids and rAmpSeq to map the loci controlling the determinants of aerial root development, mucilage production, and associative nitrogen fixation.Analyze the molecular and biochemical basis of mucilage production and degradation on aerial roots in response to water. This objective will be achieved using RNA-Seq and enzymatic assays to analyze the molecular and biochemical basis of mucilage production and degradation on aerial roots in response to water.Understand and improve the transfer of fixed nitrogen between diazotrophs and corn in aerial roots. We will address this objective using a combination of 16S and ITS amplicon sequencing, microbe isolation, and inoculation experiments to understand and improve the transfer of fixed nitrogen between diazotrophs and corn in aerial roots.