关键词: 染色体步移, T-DNA插入位点, 转基因植物, 高通量测序, 交错式热不对称PCR

Abstract: 【Objective】The purpose of this study was to establish a simple and efficient approach for identifying all T-DNA insertion sites. 【Method】A T-DNA insertion sites analysis approach based on high-throughput sequence technologies was developed, called PSORA: Parallel sequencing of one round amplicons. The process involves high-throughput amplicon sequencing of a round of thermal asymmetric PCR (TAIL-PCR) and bioinformatics analysis of T-DNA insertion sites, which reduces concerns about the specificity of TAIL-PCR. In PSORA, only two primers are required, a degenerate primer and a T-DNA specific primer. A 6-nt Barcode was designed at the 5 'end of the specific primers for labeling different transgenic events. All five transgenic events (L1, L6, L9, L15 and L19) of tobacco used in this study were produced via Agrobacterium mediated transformation with plasmids pBI121. In addition, the results of PSORA are confirmed by standard PCR. 【Result】The T-DNA insertion sites of five transgenic events were analyzed by PSORA. The results showed that L6 contained two insertion sites (36 316 bp on NW_015801367 and 42 202 bp on NW_015950898), the lines of L9, L15 and L19 each contained one insertion site (The insertion site of L9 was located at 235 969 bp on NW_015943682. The insertion site of L15 was located at 60 529 bp on NW_015802951 and the insertion site of L19 was located at 12 188 bp on NW_015863435.), but the insertion site of L1 could not be detected. PCR was performed to validate the results from bioinformatics analysis, transgenic events with different insertion sites were used as negative controls for each other, and the wild type (WT) was used as a blank control. The results showed that specific amplification consistent with expectations was obtained in each transgenic event. The effectiveness of PSORA was successfully confirmed. 【Conclusion】PSORA is an effective strategy to analyze T-DNA insertion sites. PSORA can parse the comprehensive molecular characteristics of all T-DNA insertion events simultaneously, making it simpler and faster than the traditional methods of genome walking.

Key words: genome walking, T-DNA insertion sites, transgenic plant, high-throughput sequencing, TAIL-PCR