“Corn, one of the world’s most vital staple crops, may soon benefit from a revolutionary genetic breakthrough with profound implications for agriculture and the environment. Recent work conducted at the University of Illinois Urbana-Champaign has unveiled that introducing specific genes from corn’s wild ancestor, teosinte, into modern commercial corn strains suppresses soil microbes that cause nitrogen loss and greenhouse gas emissions…

Previous findings from 2021 revealed that teosinte roots secrete chemicals capable of suppressing the activity of nitrifying and denitrifying microbes. This fascinating microbial inhibition maintains soil nitrogen in the more stable ammonium form, reducing losses and enhancing nitrogen use efficiency. The new study expanded on this insight by examining near-isogenic lines (NILs), which are modern corn lines containing small gene segments from teosinte. By growing 42 NILs alongside pure B73 (a well-characterized modern inbred corn line) and teosinte itself in field trials, they monitored changes in rhizosphere microbial populations and nitrification potential.

The results were remarkable. Two NILs exhibited a striking 50% decrease in nitrification activity compared to B73, while two others showed similarly robust suppression of denitrification. Many additional lines reduced denitrification to varying extents. These introgressed teosinte genes selectively modulated root chemistry in a way that negatively impacted nitrifier and denitrifier activity without compromising the plant’s ability to absorb nitrogen. Moreover, these microbiome-mediated traits are robust; they behave dominantly, persisting even when introgressed into hybrid corn backgrounds, and crucially, they do so without any yield penalty.”

From Bioengineering.