Abstract: The effects of aluminum stress on photosynthesis and active oxygen metabolism were investigated by chlorophyll fluorescence and enzymatic technology in C4 Ppc transgenic rice. The results showed that under Al stress, chlorophyll content, photosynthetic rate and chlorophyll fluorescence parameters Fv/Fm, φPS Ⅱ, qP and qN in C4 Ppc transgenic rice declined significantly less than those in the wild type. The results indicated that C4 Ppc transgenic rice still showed higher photosynthetic efficiency under Al stress compared to the wild type. Al treatment led to an increase in active oxygen content in rice. However, the active oxygen scavenging enzymes such as SOD, POD and CAT in C4 Ppc transgenic rice were significantly higher than those in the wild type, revealing the lipid peroxidation was lower in C4 Ppc transgenic rice. The results indicated that the introduction of C4 Ppc into rice significantly enhanced aluminum tolerance.

Key words: C4, Ppc transgenic rice, Photosynthesis, Chlorophyll fluorescence, Active oxygen metabolism