Methane-oxidizing activities and methanotrophic populations associated with wetland rice plants
Methane-oxidizing activities and methanotrophic populations associated with wetland rice plants
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DOI：
10.1007/s003740050241
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发表时间：
1997-03
影响因子：
6.5
通讯作者：
I. Watanabe;T. Hashimoto;A. Shimoyama
中科院分区：
文献类型：
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作者：
I. Watanabe;T. Hashimoto;A. Shimoyama
500 μl - 1的乙炔对缺氧土壤甲烷生成的影响不超过12 h，但对甲烷生成的抑制作用较强。为了确定水稻盆中甲烷的氧化程度，研究了乙炔对甲烷排放的影响。两种水稻品种（丰口和山光）在一个温室的盆中浸没土壤中种植。在分蘖、抽穗和籽粒形成的最大阶段，测量了甲烷通量。从下午6点开始测量3 h的通量，然后在一些锅中加入100 μl - 1的乙炔。早上6点。第二天，再次测量甲烷通量，持续3小时。仅在丰丰丰分蘖期，乙炔引起的甲烷通量显著增加（1.4倍），而在其他处理中，乙炔没有引起甲烷通量的显著增加。为了确定甲烷单加氧酶（MMO）的活性，用水稻植株的根和茎的基部测量了丙烯生成环氧丙烷（PPO）的情况。测得PPO h - 1plant - 1含量为0.1 ~ 0.2 μmol。根系每克干物质PPO生成量最高，基茎次之。甲烷氧化大致与PPO形成成正比。用平板计数法测定可溶性mmo阳性的甲烷化菌群。每克干物质的菌落形成单位数为根系106 ~ 105in，基茎104 ~ 103in。这些结果表明，湿地水稻可能会发生甲烷氧化。
Acetylene up to 500 μl l–1did not affect methane formation in anoxic soil up to 12 h, but further incubation for 1 week showed strong inhibition of methanogenesis. To ascertain the extent of the oxidation of methane produced from rice-planted pots, the effect of acetylene on methane emission was studied. Two rice varieties (Toyohatamochi and Yamahikari) were grown in a greenhouse in submerged soil in pots. At about maximum tillering, heading, and grain-forming stages, methane fluxes were measured. Flux measurement was performed for 3 h from 6 pm, then acetylene at 100 μl l–1was added to some of the pots. At 6 a.m. the following day, methane fluxes were again measured for 3 h. Only at maximum tillering stage of the variety Toyohatamochi was a significant increase (1.4 times) in methane flux caused by acetylene observed, whereas in the other treatments no significant increase in methane fluxes by acetylene could be defected. To ascertain the activity of methane monooxygenase (MMO), propylene oxide (PPO) formation from propylene was measured with excised roots and a basal portion of stems of the rice plants grown on the submerged soil. A level of 0.1–0.2 μmol PPO h–1plant–1was recorded. The roots showed the highest PPO formation per gram dry matter, followed by basal stems. Methane oxidation was roughly proportional to PPO formation. Soluble MMO-positive methanotroph populations were measured by plate counts. The number of colony-forming units per gram dry matter was 106–105in roots, and 104–103in basal stems. These results indicate the possibility of methane oxidation in association with wetland rice plants.