Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University Kyoto, Japan ; Center for Fostering Young and Innovative Researchers, Nagoya Institute of Technology, Nagoya Aichi, Japan.
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University Kyoto, Japan.
Front Microbiol. 2014 Feb 3;5:30. doi: 10.3389/fmicb.2014.00030. eCollection 2014.
This study investigated the potential local CH4 sink in various plant parts as a boundary environment of CH4 emission and consumption. By comparing CH4 consumption activities in cultures inoculated with parts from 39 plant species, we observed significantly higher consumption of CH4 associated with aquatic plants than other emergent plant parts such as woody plant leaves, macrophytic marine algae, and sea grass. In situ activity of CH4 consumption by methanotrophs associated with different species of aquatic plants was in the range of 3.7-37 μmol·h(-1)·g(-1) dry weight, which was ca 5.7-370-fold higher than epiphytic CH4 consumption in submerged parts of emergent plants. The qPCR-estimated copy numbers of the particulate methane monooxygenase-encoding gene pmoA were variable among the aquatic plants and ranged in the order of 10(5)-10(7) copies·g(-1) dry weight, which correlated with the observed CH4 consumption activities. Phylogenetic identification of methanotrophs on aquatic plants based on the pmoA sequence analysis revealed a predominance of diverse gammaproteobacterial type-I methanotrophs, including a phylotype of a possible plant-associated methanotroph with the closest identity (86-89%) to Methylocaldum gracile.
本研究调查了各种植物部位作为 CH4 排放和消耗的边界环境中潜在的局部 CH4 汇。通过比较接种 39 种植物部分的培养物中的 CH4 消耗活性，我们观察到与木本植物叶片、大型海洋藻类和海草等其他挺水植物部分相比，水生植物的 CH4 消耗活性显著更高。与不同水生植物相关的甲烷营养菌的原位 CH4 消耗活性范围为 3.7-37 μmol·h(-1)·g(-1)干重，比挺水植物水下部分的附生 CH4 消耗活性高 5.7-370 倍。基于 pmoA 序列分析对水生植物上的甲烷营养菌进行的 qPCR 估计的颗粒态甲烷单加氧酶编码基因 pmoA 的拷贝数在不同水生植物之间存在差异，范围为 10(5)-10(7)拷贝·g(-1)干重，与观察到的 CH4 消耗活性相关。基于 pmoA 序列分析对水生植物上的甲烷营养菌的系统发育鉴定表明，以多样的γ-变形菌为主的 I 型甲烷营养菌占主导地位，包括与 Methylocaldum gracile 具有最接近亲缘关系（86-89%）的可能与植物相关的甲烷营养菌的一个类群。
