Structural inflexibility of the rhizosphere microbiome in mangrove plant Kandelia obovata under elevated CO2

Panqing Yin; Mengqing Yin; Zhonghua Cai; Guoqiang Wu; Guanghui Lin; Jin Zhou

doi:10.1016/j.marenvres.2018.07.013

Structural inflexibility of the rhizosphere microbiome in mangrove plant Kandelia obovata under elevated CO₂

Mar Environ Res. 2018 Sep:140:422-432. doi: 10.1016/j.marenvres.2018.07.013. Epub 2018 Jul 24.

Authors

Panqing Yin¹, Mengqing Yin², Zhonghua Cai², Guoqiang Wu³, Guanghui Lin², Jin Zhou⁴

Affiliations

¹ Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055, Guangdong Province, PR China; The School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou, 730050, Gansu Province, PR China.
² Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055, Guangdong Province, PR China.
³ The School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou, 730050, Gansu Province, PR China.
⁴ Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055, Guangdong Province, PR China. Electronic address: zhou.jin@sz.tsinghua.edu.cn.

PMID: 30055835
DOI: 10.1016/j.marenvres.2018.07.013

Abstract

Rhizosphere microbial communities play an important role in mediating the decomposition of soil organic matter. Increased CO₂ concentration may increase plant growth by stimulating photosynthesis or improving water use efficiency. However, possible eco-physiological influences of this greenhouse gas in mangrove plants are not well understood, especially how rhizosphere microbial communities respond to CO₂ increase. We characterized the effect of elevated CO₂ (eCO₂) on rhizospheric microbial communities associated with the mangrove plant Kandelia candel for 20 weeks, eCO₂ increased plant chlorophyll a levels and root microbial biomass. Operational taxonomic unit analysis revealed no significant effects of eCO₂ on rhizospheric bacterial communities; however, some influence on archaeal community structure was observed, especially on the ammonia-oxidizing archaea. Principal component analysis showed that microbial biomass C, total nitrogen, C/N ratio, nitrate nitrogen, and salinity were the main factors structuring the microbial community. The relative contribution of environmental parameters to variability among samples was 31.0%. In addition, functional analysis by average well color development showed that carbon source utilization under eCO₂ occurred in the order amino acids > carbohydrates > polymers > carboxylic acids > amines > phenolic acids; whereas, sugars, amino acids, and carboxylic acids were the preferred carbon sources in control groups. Differences in utilization ability of carbohydrates and amino acids resulted in changes in carbon metabolism between the two groups. Rhizosphere microbial communities appear to have some buffering ability in response to short-term (20 weeks) CO₂ increase, during which the metabolic efficiency of carbon sources is changed. The results will help better understand the structural inflexibility and functional plasticity of the rhizosphere microbiome in mangrove plants facing a changing environment (such as global climate change).

Keywords: Elevated CO(2); Functional plasticity; Kandelia obovata; Rhizosphere microorganisms; Structural inflexibility.

MeSH terms

Carbon Dioxide / metabolism*
Microbiota*
Rhizophoraceae / microbiology*
Rhizosphere*

Substances

Carbon Dioxide