Effect of Elevated CO2 Concentration, Elevated Temperature and No Nitrogen Fertilization on Methanogenic Archaeal and Methane-Oxidizing Bacterial Community Structures in Paddy Soil.
Elevated concentrations of atmospheric CO2 ([CO2]) enhance the production and emission of methane in paddy fields. In the present study, the effects of elevated [CO2], elevated temperature (ET), and no nitrogen fertilization (LN) on methanogenic archaeal and methane-oxidizing bacterial community structures in a free-air CO2 enrichment (FACE) experimental paddy field were investigated by PCR-DGGE and real-time quantitative PCR. Soil samples were collected from the upper and lower soil layers at the rice panicle initiation (PI) and mid-ripening (MR) stages. The composition of the methanogenic archaeal community in the upper and lower soil layers was not markedly affected by the elevated [CO2], ET, or LN condition. The abundance of the methanogenic archaeal community in the upper and lower soil layers was also not affected by elevated [CO2] or ET, but was significantly increased at the rice PI stage and significantly decreased by LN in the lower soil layer. In contrast, the composition of the methane-oxidizing bacterial community was affected by rice-growing stages in the upper soil layer. The abundance of methane-oxidizing bacteria was significantly decreased by elevated [CO2] and LN in both soil layers at the rice MR stage and by ET in the upper soil layer. The ratio of mcrA/pmoA genes correlated with methane emission from ambient and FACE paddy plots at the PI stage. These results indicate that the decrease observed in the abundance of methane-oxidizing bacteria was related to increased methane emission from the paddy field under the elevated [CO2], ET, and LN conditions.
Soil Biology and Chemistry, Graduate School of Bioagricultural Sciences, Nagoya University.
Dongyan
D
Liu
Kanako
K
Tago
Masahito
M
Hayatsu
Takeshi
T
Tokida
Hidemitsu
H
Sakai
Hirofumi
H
Nakamura
Yasuhiro
Y
Usui
Toshihiro
T
Hasegawa
Susumu
S
Asakawa
D000383:Agriculture / Q000379:methods; D001105:Archaea / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism* / Q000528:radiation effects; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism* / Q000528:radiation effects; D058448:Biota / Q000187:drug effects / Q000528:radiation effects; D002245:Carbon Dioxide / Q000378:metabolism*; D058645:Denaturing Gradient Gel Electrophoresis; D008697:Methane / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D012275:Oryza / Q000254:growth & development; D060888:Real-Time Polymerase Chain Reaction; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D013696:Temperature
D012987:Soil; D002245:Carbon Dioxide; D009584:Nitrogen; D008697:Methane