Carbon flow in the plant-soil-microbe continuum in response to atmospheric elevated CO₂

Elevated atmospheric CO₂ concentration likely increases the capability of photosynthesis in many plant species, and the secretion of photosynthetically-fixed carbon (C) into the rhizosphere, i.e.rhizodeposits.The changes in quantity and quality of rhizodeposits may fundamentally influence soil microbial activity and community composition, because rhizodeposits are important nutrient and energy resources to microorganisms in the rhizosphere.As microorganisms greatly influence soil C cycling, how soil microorganisms metabolize the plant-derived C will be essential to the soil C stability in climate change.This review summarized and discussed the effects of elevated CO₂ (eCO₂) on plant-C accumulation, C cycling in soil and microbial activity and community structure.The investigation on the C flow in the plant-soil-microbe continuum in response to eCO₂ would be the key to the mechanism of fresh C turnover under such environment.Regarding research perspectives in the future, isotope labelling technologies combined with metagenomic sequencing will help us to gain insight of mechanisms of plant-C turnover in the rhizosphere.