Abstract
BackgroundRecent studies demonstrated that warming and elevated carbon dioxide (CO2) indirectly affect the soil microbial community structure via plant root exudates. However, there is no direct evidence for how the root exudates affect soil microbes and how the compositions of root exudates respond to climate change.ResultsThe results showed that warming directly decreased biomass of soil-borne bacteria and fungi for Acacia mearnsii De Willd but it did not impact soil microbial community for Eucalyptus urophylla S.T. Blake. In contrast, elevated CO2 had strong direct effect on increasing soil microbial biomass for both plant species. However, plant roots could significantly increase the secretion of antibacterial chemicals (most probable organic acids), which inhibited the growth of bacteria and fungi in elevated CO2 environment. This inhibitory effect neutralized the facilitation from increasing CO2 concentration on microbial growth.ConclusionsWe concluded that climate change can directly affect microorganisms, and indirectly affect the soil microbial community structure by changes in composition and content of plant root exudates.
Highlights
Recent studies demonstrated that warming and elevated carbon dioxide (CO2) indirectly affect the soil microbial community structure via plant root exudates
Identification and quantification of A. mearnsii root exudates The gas chromatograph–mass spectrometer (GC-MS) data resulted in 39 compounds being identified from root exudates of A. mearnsii under four environmental conditions (Additional file 1: Table S1); 19 compounds coexisted in four environmental conditions but their relative contents differed significantly
Our results showed that elevated CO2 had a significant direct impact on total microbial phospholipid fatty acid (PLFA), Gram-positive bacteria PLFAs (G+), Gramnegative bacteria PLFAs (G−), fungal PLFAs (F) and actinomycetes PLFAs (A) at both E. urophylla (Additional file 1: Figure S3a) and A. mearnsii (Additional file 1: Figure S4a) soil
Summary
Recent studies demonstrated that warming and elevated carbon dioxide (CO2) indirectly affect the soil microbial community structure via plant root exudates. The response of terrestrial ecosystems to global climate change has received much attention and several comprehensive reviews have shown that atmospheric CO2 enrichment will likely increase plant biomass and forest production, based on increase net carbon assimilation and water use efficiency of most plants [2,3,4]. There is evidence of indirect effects of climate warming, such as affecting plant photosynthesis and respiration, changing the ratio of carbon and nitrogen nutrition in plants and associated root exudates inputs to the rhizosphere, witch lead to changes in soil microbial community structure [14,15,16]. Understanding how rising atmospheric CO2 and temperature affects the microbial properties through
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
