转BADH基因玉米自交系的抗旱耐盐性分析

Study on Drought and Salt Resistance of Transgenic Maize Inbred Line Containing BADH

试验以T_4代转BADH基因玉米自交系(受体亲本为"丹988")为基础材料,逐年加代纯化,通过PCR检测、Southern blotting以及实时荧光定量PCR法(Quantitative real-time PCR,qRT-PCR)来验证BADH基因在T_5和T_6代株系中能否稳定的遗传及表达,同时对T_6代转化株系进行抗旱耐盐性鉴定,对T_5与T_6代转基因玉米各株系的农艺性状进行了调查分析。结果表明:外源BADH基因以单拷贝的形式整合到玉米基因组中,且BADH基因在转基因植株各组织中均有表达,其中在叶中的表达量最高,达到1.1,而在根中的表达量只有0.1;在不同株系间的表达量也不同。对T_6代阳性植株进行干旱与盐胁迫处理后,测定脯氨酸、POD活性等生理生化指标,结果表明都明显高于受体亲本;T_5与T_6代转基因株系在株高、茎粗、穗长等农艺性状上与受体亲本无差异。该试验获得了与对照受体亲本"丹988"相比抗旱耐盐性较强、且农艺性状无显著差异的转基因玉米自交系。

Four maize inbred lines which harbor BADH gene in T4 generation were used as materials to test whether BADH gene can be steadily inherited and expressed in T5 and T6 generation inbred lines by Southern blotting and Quantitative real-time PCR. Drought and salt resistance of T6 transgenic inbred lines were tested under drought and salt resistance at seedling stage and agronomic traits of T5 and T6 lines were investigated in a field test. The results showed that exogenous BADH gene was integrated into maize genome as single copy form,and expressed in maize leaf,stem and root,especially in leaf. The relative expression level in leaf can reach 1. 1,but in root only 0. 1 level is obtained. The expression quantity between different inbred lines is different. Under drought and salt stress,proline content,POD activity,dry matter weight and MDA content of T6 inbred lines were significantly higher than those of non-transgenic line,as well as plant height and stem diameter. But in the field experiment,plant height,stem diameter,and other agronomic traits showed no significant difference between transgenic lines and non-transgenic line both in T5 and T6 generation. The above results indicated that drought and salt resistance of transgenic inbred lines were stronger than receptors＇ inbred line ＂dan988＂,and their agronomic traits had no significant difference.