Gas exchange
We tested the assimilation rate (A sat), stomatal conductance
(g s), transpiration rate (E ) and the ratio between
intercellular carbon dioxide concentration and atmospheric carbon
dioxide concentration (C i/C a) of wheat, rice and soybean
under charcoal filtered air and elevated [O3]
conditions, respectively. Under O3 stress condition,A sat, g s and E in wheat were decreased by 32.2%,
19.0%, and 16.2%, while the C i/C a were slightly
increased by 3.8%. Similarly, the adverse effect of O3on A sat, g s, C i/C a and E were
suppressed by 49.5%, 65.7%, 7.5% and 60.8% in rice and 19.6%,
52.5%, 9.6% and 47.3% in soybean, respectively (P ≤0.01, Fig.
1).