Cable bacteria drive electrochemical coupling and elemental cycling in rhizosphere: A review

Cable bacteria are a type of filamentous conductive microorganisms with the capacity of centimeter level long-range electron transfer (LDET). As a "biological cable" in the environment, they play a key role as geochemi-cal engineers in the rhizosphere microenvironment. They also drive a series of interconnected redox reactions by constructing a unique bioelectrochemical network that connects root oxygen secretion (ROL) with deep sulfide oxidation. We reviewed the colonization patterns of cable bacteria in the rhizosphere and their interactions with plants. LDET could efficiently drive the in-situ formation of sulfide detoxification and iron oxide barriers, deeply couple the sulfur iron phosphorus cycle, significantly reduce methane emissions from ecosystems such as rice paddies, and improve phosphorus fixation and retention efficiency. The interaction between cable bacteria and plants has great potential for applications in organic pollutant degradation, heavy metal stabilization, ecosystem restoration, and greenhouse gas emission reduction. This review would provide new research ideas and theoretical references for deepening the understanding of microbial-plant symbiosis and transforming it into ecological engineering strategies, such as rhizosphere remediation and greenhouse gas emission reduction.