Figure legends
Fig.1
Effects
of elevated [O3] on CO2 assimilation
rate (A sat) (A), stomatal conductance
(gs) (B), ratio of CO2 concentration in
intercellular and ambient (Ci/Ca) (C)
and transpiration rate (E) (D)
of
wheat, rice and soybean. Columns in the figure represent means ± SE
(n =6) and two asterisks (**) on bars indicate significant
differences between charcoal filtered air (CF) and elevated
[O3] (EO) treatment for each crop at the 0.01 level.
Fig. 2 Effects of elevated
[O3] on activities of superoxide dismutase (SOD)
(A), peroxidase (POD) (B), and catalase (CAT) (C) and hydrogen peroxide
(H2O2) (D) in wheat, rice and soybean
leaves. Columns in the figure represent means ± SE (n =3). One
asterisk (*) and two asterisks (**) on bars indicate significant
differences at the 0.05 and 0.01 level between charcoal filtered air
(CF) and elevated [O3] (EO) treatment for each crop,
respectively.
Fig.
3 Principal component analysis (PCA) and partial least squares
discriminant analysis (PLS-DA) for the three crops. A: PCA analysis
between sample groups. B-D: PLS-DA score plots of the metabolite
profiles of different crops in treatment and control groups. B: Tae,
wheat; C: Osa, rice; D: Gma, soybean.
Fig.
4 Differential metabolites. (A) The common or specific different
metabolites in three species under elevated O3. (B-D)
Classification of
differential
metabolites under O3 stress according to chemical groups
identified in three species wheat (B), rice (C) and soybean (D).
Fig.5
KEGG enrichment analysis of differential metabolites in wheat, rice,
and soybean
(P <0.05). Tae, wheat; Osa, rice; Gma, soybean.
Fig.
6 Overview of metabolite changes in wheat exposed to O3.
A schematic view of different metabolic pathways in which metabolites
were affected by O3 is shown.
The
increased metabolites are marked in red and the decreased onesare marked
in blue . Abbreviations: G6P, glucose-6-phosphate; F6P,
fructose-6-phosphate; 3PGA, 3-phosphoglycerate; PEP,
phosphoenolpyruvate; HMP, hexose monophosphate pathway; MEP,
methylerythritol
4-phosphate; MVA, mevalonic acid; TCA, tricarboxylic acid cycle; IPP,
isopentene pyrophosphate; DMAPP, dimethylallyl pyrophosphate; GPP,
geranylpyrophosphate; FPP, farnese pyrophosphate; GGPP, geranylgeranyl
pyrophosphate.
Fig.
7 Overview of metabolite changes in rice exposed to O3.
A schematic view of different metabolic pathways in which metabolites
were affected by O3 is shown. The increased metabolites
are marked in red and the decreased ones are marked in blue.
Abbreviations: G6P, glucose-6-phosphate; F6P, fructose-6-phosphate;
3PGA, 3-phosphoglycerate; PEP, phosphoenolpyruvate; HMP, hexose
monophosphate pathway; MEP, methylerythritol 4-phosphate; MVA, mevalonic
acid; TCA, tricarboxylic acid cycle; IPP, isopentene pyrophosphate;
DMAPP, dimethylallyl pyrophosphate; GPP, geranylpyrophosphate; FPP,
farnese pyrophosphate; GGPP, geranylgeranyl pyrophosphate.
Fig.
8 Overview of metabolite changes in soybean exposed to
O3. A schematic view of different metabolic pathways in
which metabolites were affected by O3 is shown. The
increased metabolites are marked in red and the decreased ones are
marked in blue. Abbreviations: G6P, glucose-6-phosphate; F6P,
fructose-6-phosphate; 3PGA, 3-phosphoglycerate; PEP,
phosphoenolpyruvate; HMP, hexose monophosphate pathway; MEP,
methylerythritol 4-phosphate; MVA, mevalonic acid; TCA, tricarboxylic
acid cycle; IPP, isopentene pyrophosphate; DMAPP, dimethylallyl
pyrophosphate; GPP, geranylpyrophosphate; FPP, farnese pyrophosphate;
GGPP, geranylgeranyl pyrophosphate.
Fig.
9 The expression level of genes coding key enzymes. Columns in the
figure represent relative expression ± SE of three biological samples.
A: Rhe gene coding citrate (Si)-synthase (EC2.3.3.1); B: The gene coding
ATP citrate synthase (EC2.3.3.8); C: The gene coding isocitrate
dehydrogenase (EC1.1.1.41); D: The gene coding oxoglutarate
dehydrogenase (EC1.2.4.2); E: The gene coding aspartate transaminase
(EC2.6.1.1).