Light quality and quantity regulate aerobic methane emissions from plants.

Area of Science:

• Plant Science
• Environmental Science
• Biogeochemistry

Background:

• Increasing evidence shows plants emit aerobic methane (CH4).
• Environmental stress is known to increase these CH4 emissions.
• The impact of light quantity and quality on plant CH4 emissions remains largely unknown.

Purpose of the Study:

• To investigate how light quantity and quality affect aerobic methane (CH4) emissions in plants.
• To determine if CH4 emissions change over time and with plant age.
• To explore the relationship between light and CH4 release in both shade-intolerant and shade-tolerant species.

Main Methods:

• Investigated aerobic CH4 emissions in sunflower (shade-intolerant) and chrysanthemum (shade-tolerant) species.
• Manipulated light intensity (low vs. high) and light quality (red:far-red ratio, blue light levels).
• Measured CH4 emission rates over time and across different plant ages.

Main Results:

• Low light intensity significantly increased aerobic CH4 emissions in both species, acting as a stressor.
• Specific light qualities, such as altered red:far-red ratios and blue light, influenced CH4 emissions, with species-specific variations.
• CH4 emission rates ranged from 6.79-41.13 ng g⁻¹ DW h⁻¹ for sunflower and 18.53-180.25 ng g⁻¹ DW h⁻¹ for chrysanthemum.
• Emissions decreased with plant age, suggesting acclimation to environmental conditions.

Conclusions:

• Both light quantity and quality are significant regulators of plant aerobic CH4 emissions.
• Low light conditions can induce substantial CH4 release from plants.
• Findings suggest a common regulatory mechanism for CH4 emissions across different plant species, relevant to changing environmental factors like cloud cover.