Effects of Low Temperature Stress on Resistance Indices of Sympodial Bamboo Seedlings

An indoor low temperature experiment was conducted to study the variations of membrane permeability, malondialdehyde, soluble protein and soluble sugar contents, superoxide dismutase (SOD) and peroxidase (POD) activities and membrane lipid fatty acid content in leaves and roots of sympodial bamboo seedlings (Dendrocalamus latiflorus)under different levels of cold stress. Results showed that after low temperature pretreatment (8 °C) for 15 days, the soluble protein, soluble sugar contents and POD activities in leaves as well as soluble sugar contents and POD activities in roots were increased obviously. After cold-hardening (-2 °C) for 72 h, the soluble protein, soluble sugar contents and SOD, POD activities in leaves and SOD, POD activities and ratio of membrane lipid unsaturated fatty acid in roots with pretreatment were obviously higher than those without pretreatment. Membrane permeability in leaves with pretreatment was obviously lower than that without pretreatment. But the level of membrane lipid peroxidation in leaves with pretreatment was significantly greater than that before cold-hardening. While the level of membrane permeability and lipid peroxidation in roots with pretreatment had no significant change after cold-hardening. Overall, leaves had higher soluble protein, soluble sugar contents and POD activities to avoid low temperature injuries while roots had higher SOD, POD activities and unsaturated fatty acid to avoid membrane lipid peroxidation and membrane injuries.