Soil Biology and Chemistry, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Aichi, 464-8601, Japan.
CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China.
Microb Ecol. 2018 Apr;75(3):751-760. doi: 10.1007/s00248-017-1063-2. Epub 2017 Sep 10.
Methanogenic archaea survive under aerated soil conditions in paddy fields, and their community is stable under these conditions. Changes in the abundance and composition of an active community of methanogenic archaea were assessed by analyzing mcrA gene (encoding α subunit of methyl-coenzyme M reductase) and transcripts during a prolonged drained period in a paddy-upland rotational field. Paddy rice (Oryza sativa L.) was planted in the flooded field and rotated with soybean (Glycine max [L.] Merr.) under upland soil conditions. Soil samples were collected from the rotational plot in the first year, with paddy rice, and in the two successive years, with soybean, at six time points, before seeding, during cultivation, and after harvest as well as from a consecutive paddy (control) plot. By the time that soybean was grown in the second year, the methanogenic archaeal community in the rotational plot maintained high mcrA transcript levels, comparable with those of the control plot community, but the levels drastically decreased by over three orders of magnitude after 2 years of upland conversion. The composition of active methanogenic archaeal communities that survived upland conversion in the rotational plot was similar to that of the active community in the control plot. These results revealed that mcrA gene transcription of methanogenic archaeal community in the rotational field was affected by a prolonged non-flooding period, longer than 1 year, indicating that unknown mechanisms maintain the stability of methanogenic archaeal community in paddy fields last up to 1 year after the onset of drainage.
在稻田的充氧土壤条件下，产甲烷古菌得以存活，其群落在此条件下稳定。通过分析延长排水期内稻田-旱作轮作区产甲烷古菌活性群落的 mcrA 基因（编码甲基辅酶 M 还原酶α亚基）和转录物，评估了产甲烷古菌丰度和组成的变化。在淹水条件下种植水稻（Oryza sativa L.），旱作条件下与大豆（Glycine max [L.] Merr.）轮作。第一年在轮作区、第二年在连续的水稻（对照）区采集水稻和大豆种植前、种植期间、收获后以及旱作时的土壤样本。第二年种植大豆时，轮作区产甲烷古菌群落的 mcrA 转录物水平保持较高，与对照区群落相当，但旱作转化 2 年后，水平急剧下降了三个数量级以上。在旱作转化中存活下来的轮作区产甲烷古菌活性群落的组成与对照区的活性群落相似。这些结果表明，延长的非淹水期（超过 1 年）影响了轮作区产甲烷古菌群落的 mcrA 基因转录，表明在排水开始后长达 1 年的时间内，未知机制维持了稻田中产甲烷古菌群落的稳定性。
