Department of Biology, Saint Mary's University, 923 Robie Street, Halifax, Nova Scotia, B3H 3C3, Canada.
Department of Biology, Mount Saint Vincent University, 166 Bedford Highway, Halifax, Nova Scotia, B3M 2J6, Canada.
Plant Physiol Biochem. 2020 Dec;157:160-168. doi: 10.1016/j.plaphy.2020.10.016. Epub 2020 Oct 23.
Earlier studies have shown that plants produce methane (CH) under aerobic conditions, and that this emission is not microbial in nature. However, the precursors of aerobic CH remain under debate, and the combined effects of environmental factors on plant-derived CH requires further attention. The objective of this study was to determine the interactive effects of temperature and light intensity on CH and other relevant plant parameters in canola (Brassica napus L.). Plants were grown under two temperature regimes (22/18 °C and 28/24 °C, 16 h light/8 h dark) and two light intensities (300 and 600 μmol photons m s) for 21 days after one week of growth under 22/18 °C (16 h light/8 h dark). In this study, higher temperature had little effects on CH emissions from plants, indicating the mitigating effects of higher light intensity. Higher light intensity, however, significantly decreased CH, which was inversely related to plant dry mass. Higher light intensity decreased stem height, leaf area ratio, chlorophyll, nitrogen balance index, leaf moisture, methionine (Met) and ethylene (CH), but increased specific leaf mass, photochemical quenching, flavonoids, epicuticular wax, lysine and tyrosine. The results revealed that increased CH emissions from plants could be related to changes in plant physiological activities, which portrayed themselves in increased CH evolution, and methylated amino acids, such as Met. We conclude that higher light intensity reduces Met and, in turn, CH and CH emissions, but lower light intensity enhances CH formation through cleavage of methyl group of amino acids by reactive oxygen species, as previously suggested.
早期研究表明，植物在有氧条件下会产生甲烷（CH），并且这种排放不是微生物产生的。然而，有氧 CH 的前体仍存在争议，环境因素对植物源 CH 的综合影响需要进一步关注。本研究的目的是确定温度和光照强度对油菜（Brassica napus L.）中 CH 和其他相关植物参数的交互影响。在生长一周后，将植物在 22/18°C（16 小时光照/8 小时黑暗）和 28/24°C（16 小时光照/8 小时黑暗）两种温度制度下和 300 和 600 μmol 光子 m s 两种光照强度下分别培养 21 天。在本研究中，较高的温度对植物 CH 排放的影响较小，表明较高的光照强度具有缓解作用。然而，较高的光照强度显著降低了 CH，这与植物干质量呈反比。较高的光照强度降低了茎高、叶面积比、叶绿素、氮平衡指数、叶片水分、蛋氨酸（Met）和乙烯（CH），但增加了比叶质量、光化学猝灭、类黄酮、角质层蜡、赖氨酸和酪氨酸。结果表明，植物 CH 排放的增加可能与植物生理活动的变化有关，这些变化表现为 CH 演化和甲基化氨基酸（如 Met）的增加。我们得出结论，较高的光照强度会降低 Met，进而降低 CH 和 CH 排放，但较低的光照强度会通过活性氧对氨基酸的甲基进行裂解，从而增强 CH 的形成，如前所述。
