15 N DILUTION METHOD FOR ESTIMATING THE ABSORPTION OF ATMOSPHERIC NO2 BY PLANTS
K Okano1, T Fukuzawa2, T Tazakp2
1Division of Environmental Biology, The National Institute for Environmental Studies, Yatabe, Tsukuba, Ibaraki 305, Japan.
The New Phytologist
|April 20, 2021
Summary
The 15N dilution method accurately quantifies nitrogen dioxide (NO2) absorption in plants like sunflowers and maize. Plant NO2 uptake increases with NO2 concentration and exposure time, proving the method
Area of Science:
- Plant Physiology
- Environmental Science
- Biogeochemistry
Background:
- Nitrogen dioxide (NO2) is a significant air pollutant impacting plant health.
- Accurate methods are needed to quantify NO2 absorption by plants over extended periods.
Purpose of the Study:
- To evaluate the reliability of the 15N dilution method for quantifying NO2 absorption in Helianthus annuus and Zea mays.
- To investigate the relationship between NO2 absorption and NO2 concentration, and exposure duration.
Main Methods:
- Utilized the 15N dilution method for quantitative estimation of NO2 absorbed by plants.
- Exposed plants to varying NO2 concentrations and durations to assess absorption rates.
- Measured NO2-nitrogen uptake per unit leaf area and total plant absorption.
Main Results:
- NO2 absorption increased with higher NO2 concentrations and longer exposure times.
- Absorption rate per unit leaf area showed a linear increase with NO2 concentration up to 1 μl l-1.
- Helianthus annuus absorbed approximately three times more NO2 per unit leaf area than Zea mays.
- Absorption rate increased exponentially with exposure time, influenced by plant growth and air-soil-root uptake.
Conclusions:
- The 15N dilution method is a reliable tool for quantifying long-term NO2 absorption in plants.
- Plant NO2 uptake is influenced by pollutant concentration, exposure duration, and plant physiological responses.
- Findings contribute to understanding plant responses to air pollution and validating measurement techniques.
