Effects of Cd stress on photosynthesis
The light response curves of king grass grown under different
Cd amounts are shown in Fig. 2. The photosynthetic rates
increased gradually with increasing light intensity, and tended
to stabilize at the light intensity of 400e800 mmolm2 s1.
There were no significant differences in the slopes of light
curves of plants grown under different Cd concentrations,
except at 60 mg kg1 Cd, which had significantly increased
photosynthesis when the light intensity was higher than
400 mmolm2 s1.
The light response curves show important photosynthetic
characteristics of plants, including Amax, LCP, and LSP. Correlations
between Amax, LCP and LSP of king grass and soil Cd
concentration were performed (Fig. 3) and found that Amax
had no relationship with soil Cd concentration, while LCP and
LSP had positive relationships with Cd concentration. This
indicates that Amax was not significantly influenced by Cd,
Fig. 4