河竹鞭根对长期淹水环境的生理响应

为揭示河竹鞭根对淹水环境的生理响应机制,以在淹水环境中能长期生存的河竹为材料,测定了人工喷灌供水(对照)、淹水6个月的河竹1年生竹鞭上的一级根、二级根的根系活力、抗氧化酶活性和膜脂过氧化、渗透调节物质含量。研究结果表明:河竹根系活力、抗氧化酶活性、MDA含量、相对电导率和可溶性蛋白含量总体上一级根明显高于二级根。长期淹水环境下,河竹一级根、二级根的根系活力、抗氧化酶活性较对照均有显著降低,相对电导率、MDA含量显著升高,水中生长根的根系活力、CAT活性显著高于土中生长根,SOD、POD活性则相反,并能通过维持总体上较高水平的根系活力、抗氧化酶活性、可溶性蛋白含量来适应长期淹水环境的胁迫,尤其是一级根和水中生长根。河竹鞭根通过抗氧化系统的平衡调节作用来适应长期淹水环境,维持生存,其中一级根对淹水环境的响应明显强于二级根,水中生长根在适应淹水环境上起到重要作用。

Physiological Response of Phyllostachys rivalis Rhizome Roots to Long-term Water Stress

The purpose of this paper is to reveal the physiological response mechanism of rhizome roots of Phyllostachys rivalis to long-term water stress. The physiological response of primary and secondary rhizome roots of 1-year-old Ph. rivalis to long-term flooded conditions was studied in a pot experiment with treatments of artificial irrigation water supply (CK) and flooding six months (TR). The root activity, antioxidant enzyme activity, membrane lipid peroxidation and osmotic adjustment substance contents in bamboo rhizome roots were investigated. The results are as follows. In general, the root activity, antioxidant enzyme activity, MDA content, relative electron conduction and soluble protein content of primary roots were significantly higher than that of the secondary roots. Under long-term flooded conditions, the root activity, antioxidant enzyme activity of primary and secondary roots were significantly lower than that of the CK. The relative electron conductivity and MDA content increased significantly. The root activity and CAT activity of bamboo rhizome roots growing in water were significantly higher than those growing in soil, on the contrary were SOD and POD activity. And Ph. rivalis can adapt to stress of long-term flooded conditions by maintaining the overall higher levels of root activity, antioxidant enzyme activity, soluble protein content, especially primary roots and bamboo rhizome roots growing in water. The results indicated that the rhizome roots of Ph. rivalis could adapt to long-term flooded conditions and survived through the balance adjustment of antioxidant system. Response of primary roots to waterlogging was much stronger than the secondary roots, and the bamboo rhizome root growing in water played an important role in adapting the flooded conditions.