磷对水稻高Fe^(2+)胁迫的缓解作用

Amelioration of Fe ^(2+) Toxicity by Phosphorous in Rice

采用溶液培养法研究了高 Fe2 +胁迫下不同磷水平对粳稻 Azucena(耐铁毒基因型 )和籼稻 IR6 4 (铁毒敏感基因型 )的生长和生理特性的影响。结果表明 ,与正常供 Fe2 +相比 ,高 Fe2 +胁迫抑制了水稻地上部和根系的生长 ,降低了干物质积累量和叶片叶绿素含量。外源供磷水平的提高 ,水稻地上部和根系生长受铁毒抑制程度有所减弱 ,叶片丙二醛含量和质膜透性下降 ,POD活性和叶绿素含量增加 ,而 SOD活性则有所下降。表明在一定程度上 ,磷营养对提高水稻的耐 Fe2 +毒害具有重要作用 ,而磷对缓解 Azucena的 Fe2

A solution culture experiment was conducted to study the effects of P on growth and physiological parameters of two rice genotypes, Azucena (tolerant genotype) and IR64 (sensitive genotype) under excessive Fe 2+ stress. Results showed that Fe 2+ stress significantly inhibited the growth of rice shoot and root and decreased the chlorophyll content in rice leaf. The negative effect of Fe 2+ on rice growth could be ameliorated by increasing P level in the cultural solution. The ameliorating effect of P was more pronounced on the tolerant genotype, Azucena than that on sensitive genotype, IR64. P addition reduced malondialdehyde content and plasma membrane permeability and increased peroxidase activity in the leaves. It suggested that P may play an important role in increasing rice resistance to excessive Fe 2+ stress.