多糖污染是从田间水稻叶片和未成熟种子等高含糖组织中提取高质量RNA的主要限制因素。我们介绍一种简单经济的RNA提取方法,它适合从水稻叶片和未成熟种子这些富含多糖的组织中提取总RNA。这种方法可以克服产率低和质量低的问题。RNA提取后经过电泳和分光光度计分析结果表明,每克水稻组织总RNA产率在520μg到800μg之间,OD260/230比值大于2.0,OD260/280比值大于1.9。提取的RNA可以用于体外反转录cDNA、mRNA分离和基因表达系列分析(serial analysis of gene expression,SAGE)库的构建。
The success for genetic transformation of maize (Zea mays L.) is highly related to genotype of target material. A few model varieties can be induced into type Ⅱ callus, which can be easily transformed with high regeneration frequency. However, most of cultivars could be only induced into type Ⅰ callus, which is difficult to be transformed with low regeneration. Thus, studying on the conditions of induction and transformation for type Ⅰ callus will show great importance for improving elite of maize directly with genetic engineering. Bacillus thuringiensis toxin protein (cry1Ac3) gene was successfully delivered into type Ⅰ calli of two elite inbred lines of maize, 340 and E28, via particle bombardment in this work. Fertile transgenic corn plants were obtained through phosphinothricin (PPT) or hygromycin B (HygB) selection, and the results of PCR, Southern blot assay and ELISA showed that foreign genes had been integrated into maize genome and expressed. In the meantime, strong resistance of some transgenic plants to corn borer was showed through bioassay. In addition, the comparison of selective effect between PPT and HygB showed that PPT, as a selective agent, was better than HygB for the growth and regeneration of resistant calli.
In this note, we report a novel and efficient three primers PCR (TP-PCR) method to rapidly generate recombinant DNA molecule at precise junction between two arbitrary DNA fragments. TP-PCR method is characterized by its reaction system with two templates and three primers, which can produce a recombinant DNA molecule in one PCR reaction. The main advantages of this method are the independence of sequences at the recombination site, the rapid-ness, and the easy establishment of adequate conditions. This method has been successfully applied to constructing a fusion protein gene, sck gene.
