Nonmicrobial aerobic methane emission from poplar shoot cultures under low-light conditions.
The aerobic formation of methane in plants has been reported previously, but has been questioned by a number of researchers. Recently, isotopic evidence demonstrated that ultraviolet irradiation and heating lead to photochemical or thermal aerobic methane formation mainly from plant pectin in the absence of microbial methane production. However, the origin of aerobic methane formation from plant material observed under low temperature and low-light/dark conditions is still unclear. Here we show that Grey poplar (Populus × canescens, syn. Populus tremula × Populus alba) plants derived from cell cultures under sterile conditions released 13C-labeled methane under low-light conditions after feeding the plants with 13CO2. Molecular biological analysis proved the absence of any microbial contamination with known methanogenic microorganisms and ruled out the possibility that methane emission from our poplar shoot cultures under aerobic low-light/dark and ambient temperature conditions could be of microbial origin. The CH4 release rates in our experiment were in the range of 0.16-0.7 ng g-1 DW h-1, adding evidence to the growing opinion that the quantitative role of aerobic methane emissions from plants in the global methane budget, at least from cold temperate or boreal regions, is only of minor importance.
Brüggemann
Nicolas
N
Research Centre Karlsruhe, Institute of Meteorology and Climate Research (IMK-IFU), Kreuzeckbahnstrasse 19, D-82467 Garmisch-Partenkirchen, Germany.
Meier
Rudolf
R
Research Centre Karlsruhe, Institute of Meteorology and Climate Research (IMK-IFU), Kreuzeckbahnstrasse 19, D-82467 Garmisch-Partenkirchen, Germany.
Steigner
Dominik
D
Research Centre Karlsruhe, Institute of Meteorology and Climate Research (IMK-IFU), Kreuzeckbahnstrasse 19, D-82467 Garmisch-Partenkirchen, Germany.
Zimmer
Ina
I
Research Centre Karlsruhe, Institute of Meteorology and Climate Research (IMK-IFU), Kreuzeckbahnstrasse 19, D-82467 Garmisch-Partenkirchen, Germany.
Louis
Sandrine
S
Research Centre Karlsruhe, Institute of Meteorology and Climate Research (IMK-IFU), Kreuzeckbahnstrasse 19, D-82467 Garmisch-Partenkirchen, Germany.
Schnitzler
Jörg-Peter
JP
Research Centre Karlsruhe, Institute of Meteorology and Climate Research (IMK-IFU), Kreuzeckbahnstrasse 19, D-82467 Garmisch-Partenkirchen, Germany.
D000332:Aerobiosis / Q000528:radiation effects; D001419:Bacteria / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism; D002247:Carbon Isotopes; D018744:DNA, Plant / Q000235:genetics; D004587:Electrophoresis, Agar Gel; D007553:Isotope Labeling; D008027:Light; D008697:Methane / Q000378:metabolism*; D010788:Photosynthesis / Q000528:radiation effects; D018520:Plant Shoots / Q000378:metabolism* / Q000528:radiation effects; D016133:Polymerase Chain Reaction; D032107:Populus / Q000378:metabolism* / Q000528:radiation effects*; D046509:Tissue Culture Techniques
D002247:Carbon Isotopes; D018744:DNA, Plant; D002245:Carbon Dioxide; D008697:Methane