Soil carbon can reside for many thousands of years, but the residence time of organic matter can vary widely and is often dictated by diverse microbial processes. After roots die, decaying root tissues are colonized by a succession of microorganisms and become encased in protein- and polysaccharide-rich extracellular polymeric substances. All this material, along with a mixture of intracellular and extracellular biomolecules released following microbial cell death, is the molecular starting point for stabilized carbon.
Using stable isotope tracing, we are tracking the flow of carbon from roots into the soil microbial community and surrounding mineral matrix using genome-resolved isotope tracing tools that our IGI team members have pioneered. We are using metagenomics to track how microbes respond to modified plant traits, mapping the carbon flow from plants to microbes and into the ground using isotope measurements of DNA and mineral-bound carbon.
Read more about the IGI's overall work on using CRISPR for carbon removal.