Making plant methane formation visible-Insights from application of

Area of Science:

• Plant physiology
• Biogeochemistry
• Environmental science

Background:

• Methane (CH4) emissions from vegetation are highly variable, hindering accurate global estimations.
• The precise mechanisms of CH4 formation within plants are not well understood.

Purpose of the Study:

• To develop a novel method for visualizing and quantifying plant-derived CH4.
• To investigate the influence of light conditions on CH4 production pathways in plants.
• To identify potential precursors for vegetative CH4 formation.

Main Methods:

• Application of 13C-labeled dimethyl sulfoxide (DMSO) to plant leaves (Nicotiana tabacum and Miscanthus sinensis).
• Monitoring of stable carbon isotope ratios (δ13C-CH4) in headspace CH4 under varying light conditions.
• Quantification of CH4 formation rates based on isotopic signatures.

Main Results:

• Both plant species exhibited increased headspace δ13C-CH4 values under light exposure.
• Light intensity differentially affected CH4 formation rates: increasing in N. tabacum, decreasing in M. sinensis.
• N. tabacum showed no CH4 production in the dark, while M. sinensis produced approximately 50% of its light-exposed rate.

Conclusions:

• Vegetative CH4 formation is significantly influenced by light conditions and plant species.
• Dimethyl sulfoxide (DMSO) is identified as a potential precursor for plant-derived CH4.
• The stable isotope tracing approach offers high temporal resolution for studying pathway-specific CH4 emissions.