【Objective】The objective is to compare the effects of Candidatus Liberibacter asiaticus(CaLas) infection on the activity of superoxide dismutase (SOD) and peroxidase (POD) in three organs, i.e. leaves, stems and roots of Catharanthus roseus.【Method】The activities of SODand POD in the leaves, stems and roots of C. roseus infected by CaLas were determined by spectrophotometer method.【Result】The activity of SOD in the affected C. roseus decreased gradually with the increase of infection duration. When the activity was the lowest, the activity of SOD in the leaves, stems and roots was only 61%, 55% and 47% respectively of that of the healthy control group. Among these three organs, the leaves had the highest SOD activity while the roots had the lowest. The activity of POD in the affected C. roseus increased first and then decreased with the increase of infection duration. The activity of POD in leaves, stems and roots reached the highest 30, 35 and 35 days after grafting, and was 205%, 254% and 194% respectively of that of the healthy control group. The activity of POD in roots was much higher than that in leaves and stems【Conclusion】The infection of CaLas has a great effect on the activity of SOD and POD in the organs of C. roseus. The increase of SOD and POD activities plays an important role in the resistance of C. roseus to CaLas infection.
Guangdong Agricultural Sciences