Abstract: Methane is an important greenhouse gas produced by anaerobic methanogenic microbes and transported and released to the atmosphere mainly through plants. Recent studies have found that plants can produce methane under aerobic conditions, which is highly controversial. Whether plants emit methane and the mechanism of methane production requires further research. Some studies have found that pectin, lignin, cellulose, methionine, and wax layers are the main precursors for plant methane emissions. Methane emissions can be detected under normal or environmental stress conditions. External stimuli, such as high temperature, ultraviolet radiation, mechanical damage, and drought stress, can induce methane emissions from plants. The increase in methane emissions is related to the accumulation of reactive oxygen species produced within the plant. Under stress conditions, reactive oxygen produced inside the plant attacks the polysaccharide chains in the cell wall, causing them to degrade and thus increasing the number of methoxy groups in the cell, leading to an increase in methane emission. The understanding of the precursors for methane emissions within the plant body is not comprehensive enough, and the mechanism of methane emissions is not clear. Whether plants are considered an important source of methane emissions is also controversial. More research is needed to improve the understanding of the precursors and mechanisms of methane production within plants. These studies will provide scientific basis for better accounting for atmospheric methane emission sources and more accurate estimation of global methane emissions.

Key words: aerobic environment, methane emission, carbon cycle, pectin, reactive oxygen species