Elevated Atmospheric CO2 and Nitrogen Fertilization Affect the Abundance and Community Structure of Rice Root-Associated Nitrogen-Fixing Bacteria

• DOI: 10.3389/fmicb.2021.628108
• Publication Date: 2021-04-21T05:20:12Z
• Authors: Jumei Liu; Jingjing Han; Chunwu Zhu; Weiwei Cao; Ying Luo; Meng Zhang; Shaohua Zhang; Zhongjun Jia; Ruihong Yu; Ji Zhao; Zhihua Bao
• Keywords: 2. Zero hunger; 0303 health sciences; nitrogen fertilization; 15. Life on land; Microbiology; QR1-502; 6. Clean water; elevated atmospheric CO2; 03 medical and health sciences; rice paddy; 13. Climate action; growth stages; plant-associated nitrogen-fixing bacteria

Elevated atmospheric CO 2 (eCO ) results in plant growth and N limitation, yet how root-associated nitrogen-fixing bacterial communities respond to increasing nitrogen fertilization (eN) during the stages of rice is unclear. Using nifH gene as a molecular marker, we studied combined effect eCO eN on diazotrophic community abundance at two (tillering, TI heading, HI). Quantitative polymerase chain reaction (qPCR) showed that had no obvious roots under either ambient (aCO or treatment stage; contrast, HI, copy numbers were increased decreased aCO . For rhizosphere soils, significantly reduced both HI stage. soils with fertilization, but without addition There was significant interaction [CO × fertilization] root zone In addition, higher stage than Sequencing analysis indicated structure tended cluster according Rhizobiales dominant diazotrophs all samples Additionally, relative Methylosinus ( Methylocystaceae treatment, Rhizobium Rhizobiaceae treatment. Overall, stimulates methane-oxidizing bacteria while inhibits heterotrophic diazotrophs.