Tropospheric O₃, the nightmare of wild plants: a review study

Abstract

Ambient ozone (O 3 ) poses a growing threat to the global ecosystems due to its high phytotoxicity: it may possibly reduce the productivity of wild plants as well as the species' biodiversity. Asia hosts a remarkable number of wild plant species; thus, studies dealing with Asian species' responses to O 3 are of great importance. We have retrieved, from scientific databases, 195 papers dealing with the response of 473 wild plants species to O 3 . Some species we characterize as "ozonophobic" have been reported to be negatively affected by O 3 , even at O 3 levels lower than the AOT40 threshold. This review revealed the lack of research dealing with the effects of O 3 on endangered or threatened plant species, as well as on important medical plants. Such research is needed not only from an ecological point of view or in terms of biodiversity value, but also from an anthropocentric point of view. Several wild species carry unique substances that are used in medicines for healing human diseases or in agro-industry for the production of agrochemicals, thus securing human welfare.

Ozone‐induced foliar damage and release of stress volatiles is highly dependent on stomatal openness and priming by low‐level ozone exposure in Phaseolus vulgaris

“…Both plant growth and production as well as plant species biodiversity are significantly disturbed under elevated O 3 conditions, which portends a significant threat to global food security (e.g. Schimidhuber & Tubiello 2007;Feng, Kobayashi, & Ainsworth 2008;Furlan et al 2008;Wittig, Ainsworth, Naidu, Karnosky, & Long 2009;Ainsworth, Yendrek, Sitch, Collins, & Emberson 2012;Wilkinson, Mills, Illidge, & Davies 2012;Agathokleous, Saitanis, & Koike 2015;Cassimiro & Moraes 2016;Freire et al 2017). It is estimated that the average current background concentration of O 3 in the northern hemisphere is around 20-50 nmol mol À1 and O 3 concentrations are predicted to increase due to expected rise in O 3 precursor emissions in the future, implying even greater effects of tropospheric O 3 on global climate change and on atmospheric oxidative status by the end of this century (Vingarzan 2004;Fowler et al 2008).…”

Foliar chemical composition of two oak species grown in a free-air enrichment system with elevated O₃ and CO₂

“…Koike et al, 2013). Thus, O 3 has been regarded as one of the most serious environmental stresses for plants (Matyssek et al, 2012;Agathokleous et al, 2015), concerning with forest decline and tree dieback in East Asia (Izuta and Nakaji, 2003;Izuta, 2006;Watanabe et al, 2005). O 3 concentration usually shows the highest value from spring to summer in northeast Japan (Yamaji et al, 2006).…”

Effects of CO₂ and O₃ on the interaction between root of woody plants and ectomycorrhizae

“…It has been reported that elevated O 3 reduces C assimilation and limits the allocation of photosynthates to below-ground (Grantz and Farrar 2000;King et al 2005;Agathokleous et al 2015b). High O 3 levels may weaken the specific rate of inorganic N uptake by roots (Haberer et al 2007) and decrease the standing crop of fine root and sporocarp production of ECM fungi (Kasurinen et al 2005;Andrew and Lilleskov 2009).…”

“…Apparently, though, this relationship is unstable under changing environmental conditions. Current concentrations of O 3 have significant adverse effects on forests (Ashmore 2005;Yamaguchi et al 2011;Agathokleous et al 2015b). Most experiments of O 3 effects on trees are based on an assessment of above-ground parts, and much less is known about below-ground processes (Andersen 2003).…”