A group from Department of Animal, Plant and Soil Sciences, Centre for AgriBioscience, La Trobe University, Melbourne Campus, Bundoora, Victoria, Australia, etc. has reported on changes in the rhizosphere of wheat due to elevated atmosphric CO2 and mineralization of organic phosphorus.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8785599/
Phosphorus (P) is fundamentally important to soil biota as a major building block of life. Since organic P comprises up to 80% of total P in soils, the mineralization of organic P by soil microorganisms could have the potential to be a prominent process in P transformation, especially the mineralization of a dominant component of organic P such as phytate.
While plant roots release extracellular phosphatases, much of this enzyme activity is restricted to the root surface. Thus, active mineralization of soil organic P mainly takes place in rhizosphere where soil microorganisms interact with plant-derived C.
Climate change has the potential to impact organic P transformation. One of most important climate change factors, elevated atmospheric CO2 concentration (eCO2), would considerably accelerate the mineralization of soil organic P. The acceleration of organic P mineralization is attributed to modified plant-soil-microbe interactions due to changes in the plant carbon (C) flow belowground.
Authors quantified the microbial contribution to mineralization of organic P under eCO2 by exploring the community-wide genetic profiling of soil microorganisms, including bacterial and fungal communities and their functions in relation to mineralization of a major organic P compound, phytate, in the rhizosphere of wheat.
Microbial diversity was more clearly affected by eCO2 in the Chromosol than in the Vertosol. Elevated CO2 significantly increased bacterial species richness by 33% across the within 3 mm rhizosphere compartments in the Chromosol. In the Vertosol, however, rhizobacteria were not significantly affected by eCO2. Abundances of two major bacterial phyla, Bacteroidetes and Gemmatimonadetes were relatively enriched in the rhizosphere under eCO2 and positively associated with the mineralization of phytate. The most prevalent Bacteroidetes families were Chitinophagaceae and Microscillaceae, followed by Sphingobacteriaceae and Hymenobacteraceae.
The fungal community had also greater species richness in the within 3 mm rhizosphere compartments when wheat plants were grown under eCO2 in the Chromosol. However, in the Vertosol, CO2 treatment did not significantly affect any indicators of α-diversity of fungal community. eCO2 significantly increased the abundances of Basidiomycota genus Agaricus, and the genera Claroideoglomus and Funneliformis of Glomeromycota in the Chromosol.