Influence of rice cultivars on soil bacterial microbiome under elevated carbon dioxide

Abstract

Purpose

Elevated CO₂ concentration (eCO₂) may stimulate plant growth and influence the soil microbial community, but questions remain for whether microbial responses to elevated CO₂ would vary by different CO₂-responsive plants. We thus attempted to elaborate the changes of soil microbiome to different rice cultivars under the eCO₂ condition.

Materials and methods

Two rice cultivars, i.e., the CO₂-tolerant cultivar, Wuyunjing23 (WYJ23), and the CO₂-sensitive one, Yandao 6 (YD6), were grown under eCO₂ and ambient CO₂ (aCO₂) conditions. The contents of dissolved organic carbon (DOC) and nitrogen (DON) in soil were measured. Real-time qualitative PCR (qPCR) and high-throughput sequencing techniques were employed to characterize the bacterial community. Furthermore, co-occurrence network analysis was applied to reveal the ecological interactions among bacterial taxa.

Results and discussion

No significant differences were found among all treatments in terms of bacterial population, alpha-diversity indices, and bacterial community structure. However, the topological parameters of ecological networks highlighted the distinct co-occurrence patterns among treatments. YD6 under eCO₂ led to more links, lower modularity, and greater centralization degree compared to that under aCO₂. Opposite trends of those parameters were observed for WYJ23 under eCO₂ compared to that under aCO₂. Besides, more Proteobacteria and Acidobacteria served as keystone taxa in the CO₂-sensitive cultivar treatments, compared to those in WYJ23, implying the different influences of rice cultivars on the microbial ecological network.

Conclusions

Different rice cultivars under eCO₂ did not influence the alpha- and beta-diversity of the soil bacterial community, but changed the co-occurrence network of the community. More attention should be paid to the assembly mechanisms of the soil microbial microbiome when evaluating the impacts of productive crops on the soil-plant ecosystem under the eCO₂ condition_.

from Energy Ecology Environment Ambio via Terpsi Hori on Inoreader http://bit.ly/2F6by1J