Open AccessLinking microbial community dynamics to rhizosphere carbon flow in a wetland rice soil
Author(s) -
Lu Yahai,
Murase Jun,
Watanabe Akira,
Sugimoto Atsuko,
Kimura Makoto
Publication year - 2004
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1016/j.femsec.2004.01.004
Subject(s) - biology , rhizosphere , photosynthesis , decomposer , microbial population biology , agronomy , carbon cycle , biomass (ecology) , soil organic matter , cycling , botany , microorganism , soil carbon , ecology , soil water , ecosystem , bacteria , history , genetics , archaeology
Photosynthesis by terrestrial vegetation is the driving force of carbon cycling between soil and the atmosphere. The soil microbiota, the decomposers of organic matter, is the second player carrying out carbon cycling. Numerous efforts have been made to quantify rhizodeposition and soil respiration to understand and predict the carbon cycling between the soil and atmosphere. However, there have been few attempts to link directly the soil microbial community to plant photosynthesis. We carried out a pulse‐chase labeling experiment in a wetland rice system in which rice plants of various ages were labeled with 13 CO 2 for 6 h and the distribution of the assimilated 13 C to soil microorganisms was estimated by analyzing the 13 C profile of microbial phospholipid fatty acids (PLFAs). The results showed that total PLFA increased with plant growth, indicating an increase of microbial biomass. But the mono‐unsaturated PLFAs increased faster than the branched chain fatty acids. The 13 C was incorporated into PLFAs immediately after the plant 13 CO 2 assimilation, proving the tight coupling of microbial activity to plant photosynthesis. In line with the finding of seasonal change in total PLFAs, more of 13 C was distributed to the straight chain fatty acids (16:0, 16:1ω7, 18:1ω7 and 18:1ω9) than to the branched chain fatty acids. The total plant carbon incorporation estimated from 13 C labeling roughly corresponded to the increase in total PLFAs over the growing season of plants. Our study suggests that microbial populations in rice soil differ greatly in their responses to plant photosynthate input.