title: Light quality and quantity regulate aerobic methane emissions from plants.
abstract: Studies have been mounting in support of the finding that plants release aerobic methane (CH4), and that these emissions are increased by both short-term and long-term environmental stress. It remains unknown whether or not they are affected by variation in light quantity and quality, whether emissions change over time, and whether they are influenced by physiological parameters. Light is the primary energy source of plants, and therefore an important regulator of plant growth and development. Both shade-intolerant sunflower and shade-tolerant chrysanthemum were investigated for the release of aerobic CH4emissions, using either low or high light intensity, and varying light quality, including control, low or normal red:far-red ratio (R:FR), and low or high levels of blue, to discern the relationship between light and CH4emissions. It was found that low levels of light act as an environmental stress, facilitating CH4release from both species. R:FR and blue lights increased emissions under low light, but the results varied with species, providing evidence that both light quantity and quality regulate CH4emissions. Emission rates of 6.79-41.13 ng g-1DW h-1and 18.53-180.25 ng g-1DW h-1were observed for sunflower and chrysanthemum, respectively. Moreover, emissions decreased with age as plants acclimated to environmental conditions. Since effects were similar in both species, there may be a common trend among a number of shade-tolerant and shade-intolerant species. Light quantity and quality are influenced by factors including cloud covering, so it is important to know how plants will be affected in the context of aerobic CH4emissions.
authors.affiliation: Department of Biology, Mount Saint Vincent University, 166 Bedford Highway, Halifax, Nova Scotia, B3M 2J6, Canada.
authors.forename: Ashley B
authors.initials: AB
authors.lastname: Martel
authors.affiliation: Department of Biology, Mount Saint Vincent University, 166 Bedford Highway, Halifax, Nova Scotia, B3M 2J6, Canada.
authors.forename: Mirwais M
authors.initials: MM
authors.lastname: Qaderi
mesh_terms: D002734:Chlorophyll / Q000378:metabolism; D031202:Chrysanthemum / Q000378:metabolism / Q000528:radiation effects*; D006368:Helianthus / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*; D008027:Light; D008697:Methane / Q000378:metabolism*; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects; D018547:Plant Stems / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects
chemical_list: D002734:Chlorophyll; D008697:Methane