Nitrogen-fixing corn slime? A Mexican maize landrace supports nitrogen-fixing microbiota in aerial root mucilage

Plants engage in intimate interactions with symbiotic microbes for the mutually beneficial exchange of nutrients. In a keystone study published in PLoS Biology, Van Deyze et al. (2018) describe the presence of nitrogen-fixing microbiota contained within an extensively carbohydrate rich mucilage found on the aerial roots of a Mexican landrace of maize (Sierra Mixe). Such interactions with nitrogen-fixing microbes are rare in non-leguminous plants (like maize), which further highlights the importance of this unique carbohydrate-for-nitrogen symbiotic transfer in aerial root mucilage. Future efforts to understand the genetic mechanisms regulating this trait in Sierra Mixe maize will aid the eventual biotechnological optimization and transfer to commercial maize varieties that would ideally reduce current dependencies on nitrogen fertilizers. (Summary by Phil Carella) PLOS Bio 10.1371/journal.pbio.2006352