水稻Act1启动子融合的bar基因在转基因燕麦T_3代中的表达

以微弹轰击法转化获得的含bar基因燕麦T3代为材料 ,运用Northernblot方法研究了bar基因在燕麦的不同生育阶段、不同叶位、以及Challenge(0 .2 0 % )处理后不同时间的叶片中mRNA水平的变化。结果表明 ,外源bar基因在燕麦的不同生育阶段、不同叶位、以及除草剂处理后转录水平没有明显差异。由于除草剂喷涂后 ,植株体内氨含量的变化能够反映bar基因编码的PAT酶活性的变化 ,因而测定了Challenge处理后不同时间、不同部位的叶片中氨含量的变化情况。结果发现 ,含bar基因的燕麦植株体内氨含量在除草剂处理后不同时间和不同部位都没有显著的变化 ,而对照植株体内氨的含量在除草剂处理后能迅速上升。这表明 ,含bar基因的燕麦植株体内由于PAT酶的稳定表达 ,而使氨的含量维持在较低水平。从转录和翻译两个层次上反映了水稻Act1启动子融合的bar基因在转基因燕麦T3 中能够稳定表达 ,且表达水平不受叶位和除草剂的影响

Regulation of bar Gene Expression in the Transgenic Oat T_3 Progeny

The spatial and temporal regulation of the bar gene in the transgenic oat T 3 progeny was analysed using Northern blot and phosphinothricin acetytransferase (PAT) enzyme assay. No difference in mRNA level was detected in the different leaves (Fig.5) and different stages of plant development (Fig.3), treated or untreated with 0.20 % commercial herbicide Challenge (Glufosinate ammonium 150 g/L). Similar results were obtained in PAT enzyme assay (Figs.4,6). These results indicate that the expression of the bar gene in the transgenic oat T 3 progeny is not regulated spatially and temporally, and was not induced by treatment with PPT (phosphinothricin), confirming that the rice actin 1 and intron 1 are constitutive promoters. Different symptoms shown in the different leaves of plant after being treated with PPT was probably due to differences in age and consequently in metabolism.