Abstract: Tocopherols are a group of powerful antioxidants, α-tocopherol is the most effective component. In this study, transgenic GmTMT2a plants (TP) with enriched-α-tocopherol and wild type plants (WT) were analyzed under drought stress. Results showed that H2O2 was accumulated in both TP plants and WT plants, however H2O2 content was less in TP plants than that in WT plants. We further analyzed the activity of antioxidant enzymes SOD, POD and CAT, and results showed that CAT actiity was obviously enhanced in TP plants compared with WT plants. Moreover P5CS and TPS transcripts were upregulated more in TP plants than WT. Our data showed that GmTMT2a increased drought tolerance of transgenic maize through promoting CAT, TPS and P5CS expression.

Key words: abiotic stress, tocopherols, antioxidant, maize, antioxidant enzymes

摘要： 生育酚具有很强的抗氧化功能，其中α-生育酚是最有效的组分。研究了α-生育酚含量提高的转GmTMT2a基因植株（TP）和野生型植株（WT）在干旱条件下的响应差异。结果表明，TP植株和WT植株中H2O2 含量均有所增加，但TP植株中累积了更少的H2O2；抗氧化酶类SOD、POD和CAT的酶活测定结果表明，CAT酶活性在TP植株中的增幅最大；抗旱相关基因表达分析结果显示，P5CS和TPS在TP植株中的表达显著上调。推测转GmTMT2a基因后，提高了CAT的酶活以及P5CS和TPS的表达量，进而增强了植株的抗旱性。

关键词: 非生物逆境, 生育酚, 抗氧化, 玉米, 抗氧化酶