Emission of isoprenoids by plants: their role in atmospheric chemistry, response to the environment, and biochemical pathways.

Plants produce and emit a wide range of compounds whose common precursor is isoprene. Because of their high reactivity with OH radicals and tropospheric O3, these compounds are relevant in atmospheric chemistry and may act as precursors of photochemical smog. They may also influence rural acid deposition and compete with methane for OH radicals, therefore indirectly influencing the global warming trend. Studies have been carried out at the plant physiology and plant biochemistry level in an attempt to measure the emission of isoprenoids by plants. A review of the present knowledge about the role of biogenic emission in atmospheric chemistry, the response of the emission to environmental factors, and the biochemical pathways of isoprenoid formation is presented.