Plant biochemistry influences tropospheric ozone formation, destruction, deposition, and response

Authors: WEDOW, JESSICA - Danforth Plant Science Center; Ainsworth, Elizabeth - Lisa; LI, SHUAI - University Of Illinois

Submitted to: Trends in Biochemical Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/29/2021
Publication Date: 7/21/2021
Citation: Wedow, J.M., Ainsworth, E.A., Li, S. 2021. Plant biochemistry influences tropospheric ozone formation, destruction, deposition, and response. Trends in Biochemical Sciences. 46(12):992-1002. https://doi.org/10.1016/j.tibs.2021.06.007.
DOI: https://doi.org/10.1016/j.tibs.2021.06.007

Interpretive Summary: Tropospheric ozone is one of the most widespread air pollutants and an important greenhouse gas that is detrimental to both human and plant health. Plant volatiles, such as isoprene, can increase ozone pollution in the lower atmosphere through formation of precursor molecules, which react with other pollutants to form ozone. Ozone is also taken up into plants through the pores on the leaf surface, which is important for reducing ozone pollution. This paper reviews the mechanisms by which plants contribute to ozone formation and destruction in the atmosphere. Additionally, new methods for monitoring the biochemical fate of ozone in plants are described. Better characterization of the radicals formed within leaves after ozone exposure would enable more accurate modeling of ozone deposition and improved strategies for ozone tolerance.

Technical Abstract: Tropospheric ozone is amongst the most damaging air pollutant to plants. Plants alter atmospheric ozone concentration ([O3]) in two distinct ways: (1) by emission of biogenic volatile organic compounds (BVOC) that act as precursors of ozone and (2) by dry deposition, which includes diffusion of ozone into vegetation through stomata and destruction of O3 by nonstomatal pathways. Isoprene, monoterpenes and higher terpenoids are emitted in large enough quantities by plants to alter tropospheric [O3]. Deposition of O3 into vegetation is related to stomatal conductance, leaf structural traits and the detoxification capacity of the apoloplast. The biochemical fate of O3 once it enters leaves and reacts with aqueous surfaces is largely unknown, but new techniques for tracking and identifying initial products have potential for opening the black box. This review highlights recent advances in understanding how plant volatile emissions influence troposphere O3 formation and destruction, and the biochemical and physiological mechanisms influencing O3 deposition into leaves.