Distinct members of a stable methanogenic archaeal community transcribe mcrA genes under flooded and drained conditions in Japanese paddy field soil
Distinct members of a stable methanogenic archaeal community transcribe mcrA genes under flooded and drained conditions in Japanese paddy field soil
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DOI：
10.1016/j.soilbio.2008.10.025
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发表时间：
2009-02
影响因子：
9.7
通讯作者：
Takeshi Watanabe;M. Kimura;S. Asakawa
中科院分区：
文献类型：
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作者：
Takeshi Watanabe;M. Kimura;S. Asakawa
通过对产甲烷关键酶甲基辅酶M还原酶α亚基（mcrA）基因及其mRNA转录本的分析，研究了日本稻田产甲烷古菌在一个年周期中的组成和演替。稻田采用双季种植管理，即夏季在淹水条件下种植水稻，冬季在排水条件下种植小麦。分别从土壤样品中提取基因组DNA和总RNA，扩增mcrA基因及其转录本。mcrA基因的最大可能数PCR估计的数量之间的样品变化不大，而那些的转录本和转录本/mcrA基因的比例增加，在水稻栽培后期淹水条件下。此外，变性梯度凝胶电泳的条带模式的mcrA基因PCR产物的样品之间是相似的，而那些从转录本是不同的样品之间的淹没和排水条件。淹水条件下水稻土的产甲烷活性高于排水条件。通过克隆文库分析，在土壤中检测到属于甲烷微生物目、甲烷菌目、甲烷细胞目（水稻簇I）、mrtA簇（同工酶基因）和甲烷杆菌科的克隆。然而，从成绩单库中的相对比例是完全不同的，即来自身份不明的Methanocinales和水稻集群I的成员的成绩单主要是在土壤中检测到淹水和排水条件下，分别。这些结果表明，成熟的产甲烷古菌群落中的不同成员转录mcrA基因，并根据土壤条件促进甲烷产生。
The composition and succession of methanogenic archaea in a Japanese paddy field were investigated during an annual cycle by analyses of methyl-coenzyme M reductase α subunit (mcrA) genes and their mRNA transcripts, which encode a key enzyme for methanogenesis. The paddy field was managed with a double-cropping cultivation, i.e. rice grown in summer under a flooded condition and wheat cultivated in winter under a drained condition. The mcrA genes and their transcripts were amplified from genomic DNA and total RNA extracted from soil samples, respectively. Numbers of the mcrA genes estimated by the most probable number-PCR showed little variation among the samples, whereas those of the transcripts and the transcripts/mcrA gene ratios increased in the late period of the rice cultivation under flooded condition. In addition, band patterns of denaturing gradient gel electrophoresis of the mcrA gene PCR products were similar among the samples, while those from the transcripts were different between the samples under flooded and drained conditions. Methanogenic activities of the paddy soils were higher under flooded conditions than drained conditions. Clones belonging to Methanomicrobiales, Methanosarcinales, Methanocellales (Rice cluster I), mrtA cluster (isoenzyme genes) and Methanobacteriaceae were detected in the soils by the clone library analysis. However, the relative proportions in the libraries from the transcripts were completely different, i.e. transcripts derived from members of unidentified Methanosarcinales and Rice cluster I were predominantly detected in the soils under flooded and drained conditions, respectively. These results suggested that distinct members in a well-established methanogenic archaeal community transcribed mcrA genes and contributed to methane production corresponding to soil conditions.