H2O2预处理对不同水稻品种Cd耐性的影响

 以耐性不同的两个水稻品种N07 63和N07 6为材料，采用水培法研究了镉（Cd）胁迫下过氧化氢（H2O2）预处理对水稻Cd耐性和吸收转运的影响及品种间差异。比较了两个品种不同处理下丙二醛（MDA）、还原型谷胱甘肽（GSH）、非蛋白巯基（NPT）、植物络合素（PCs）含量以及谷胱甘肽硫转移酶（GST）活性的变化。结果表明,50 μmol/L Cd处理显著抑制水稻生长，提高GSH、NPT、PCs、MDA含量和GST活性，且品种间差异显著。从Cd在水稻植株中的分布上看，N07 6向地上部转运的Cd比N07 63多。H2O2预处理后，两个品种Cd毒害效应减轻，GSH、NPT、PCs含量和根部GST活性得到进一步提高，且N07 63的增幅高于N07 6，其耐性也提高更多。H2O2预处理降低了两个品种的Cd向地上部转运，但对根部Cd含量存在不同的影响。从上述结果可以推测，两个品种在Cd解毒机制和对H2O2的响应上存在明显差异。

Effect of H2O2 Pretreatment on Cd Tolerance of Different Rice Cultivars

The effect of H2O2 pretreatment on Cd tolerance and translocation in rice seedlings was studied by using two rice cultivars (N07 6 and N07 63) differing in Cd tolerance. The contents of malondialdehyde(MDA), reduced glutathione (GSH), non protein thiols (NPT), phytochelatins(PCs) and the activity of glutathione S transferase (GST) were compared between the two cultivars exposed to various treatments. The results showed that 50 μmol/L Cd exposure significantly inhibited rice growth, enhanced the production of GSH, NPT, PCs, MDA and the activity of GST, and there were significant differences between the two cultivars. More Cd was transported into the shoot in N07 6. The H2O2 pretreatment alleviated Cd toxcity by further increasing GSH, NPT and PCs contents, as well as the root GST activities. The larger increase in N07 63 than in N07 6 suggests that the tolerance of N07 63 was enhanced more significantly than N07 6. H2O2 pretreatment reduced Cd translocation to rice shoots but affected the Cd concentration in roots differently. From the above results, it may be speculated that there were clear differences in the Cd detoxification and response to the H2O2 pretreatment between the two cultivars.