Traces of volatile organic compounds (VOCs) — gasses such as ethylene, nitric oxide and ethanol — play an important role in many areas of life sciences ranging from agrotechnology, microbiology, molecular biology, physiology, and phytopathology. In plants, many biological processes can be followed by ultra low-concentration gas emissions. Examples include the circadian rhythm of ethylene production in Arabidopsis thaliana and from fungus-infected tomatoes, and methane emissions from plants — which can produce methane in aerobic conditions. Nitric oxide (NO) plays an important role in plant growth and development, stomatal regulation, and protection against biotic and abiotic stresses — and can also be used to monitor the response of plants infected with pathogens.
A paper in AoB PLANTS describes new methods for online and real-time monitoring of trace gases that are now available. Laser based instruments have a sensitivity at the single part per billion level and a response time of a few seconds. This allows the dynamics of trace gases such as ethylene, nitric oxide and other VOCs released by plants under different conditions to be recorded and analysed under natural conditions. These are indispensable tools for applications which cannot be fulfilled by existing technology, such as gas chromatography.