“…Antioxidant capacity in the apoplast provides the first line of defence against O 3 and other ROS (Kangasjärvi, Jaspers, & Kollist, 2005) and is linked to tolerance to multiple environmental stresses (Scebba, Pucciarelli, Soldatini, & Ranieri, 2003). Phenolic molecules directly scavenge ROS (Grace & Logan, 2000), respond to stresses that impair photosynthesis (Koricheva, Larsson, Haukioja, & Keinanen, 1998) and increase under elevated O 3 in a variety of species (Gillespie, Rogers, & Ainsworth, 2011;Kangasjärvi, Talvinen, Utriainen, & Karjalainen, 1994;Peltonen, Vapaavuori, & Julkunen-Tiitto, 2005;Yendrek, Koester, & Ainsworth, 2015).…”