Molecular approaches to increasing plant root carbon

Carbon sequestration is a promising strategy to reduce anthropogenic greenhouse gas (GHG) levels. Of the myriad biological approaches being developed, leveraging plant roots for below-ground carbon storage offers an attractive solution that can be widely deployed. In this review we highlight the molecular pathways that can be manipulated to increase root carbon content and explore synthetic biology approaches that underpin the engineering of these traits into crop plants. Allocating more carbon to the plant root system is not without challenges, particularly if associated with reduced yield. These issues, along with the need to test the effectiveness of roots to store carbon, will be discussed, as both have important implications for the use of this technology to reduce atmospheric CO₂.