Combined Stresses in Plants: Physiological, Molecular, and Biochemical Aspects

4 Combination of Elevated CO 2 Levels and Soil Contaminants’ Stress ... 85

d

e

c

FA

CE

Ambient

0.12 0.09 0.06 0.03

0

concentration in riceCd

)-1 shoots (mg kg

1

0.8 0.6 0.4 0.2

0

FA

CE

Ambien

t

concentration in riceCd

)-1 shoots (mg kg

f

Cd

added to soil (mg kg

-1)

FA

CE

Ambien

t

0.180.150.120.090.06 0.03

0

0

0.

52

concentration in riceCd

)-1 shoots (mg kg

a

FA

CE

Ambien

t

1

0.8 0.6 0.4 0.2

0

concentration in riceCd

)-1 shoots (mg kg

concentration in riceCd

)-1 shoots (mg kg

3

2.5

2

1.5

1

0.5

0

FA

CE

Ambient

concentration in riceCd

)-1 shoots (mg kg

FA

CE

Ambien

t

2.5

2

1.5

1

0.5

0

b

Fig. 4.8

Cadmium concentrations in tissues of rice plants grown in soil

with 0, 0.5, or 2.0

mg

kg

−1

Cd, under either ambient CO

levels or elevated CO 2

levels 2

( FACE

).

a Rice shoots at the mid-tillering growth stage of the first season,

b rice shoots at the panicle-initiation growth stage of the first season,

c rice shoots at

grain maturity of the first season,

d rice seeds at grain maturity of the first season,

e rice shoots at grain maturity of the second season, and

f rice seeds at grain

maturity

of

the

second

season.

Values

represent

means

±

SD.

An

asterisk

indicates

a

significant

difference

between

FACE

and

ambient

conditions

(

p^

<^ 0.05).

FACE

free-air CO

enrichment 2