A One-time Inducible Transposon for Terminating Selectable Markers in Transgenic Plants

單次轉位之可誘導轉位子終止轉基因篩選標記

戴宏光(Hung-Kuang Tai) ； 李冠德(Kuan-Te Li) ； 常玉強(Yuh-Chyang Charng)

《Botanical Studies》 52卷4期 (2011/10) Pp. 375-381

摘要

使用篩選標記基因(selectable marker genes) 可以快速、有效篩選轉殖株，然而在獲得轉殖株後，篩選標記基因就無特殊用途，並有生物安全疑慮，本研究建構單次可誘導轉位子以終止篩選標記之功能。將轉位酶基因上游建構可誘導啟動子，且轉位子之5 端構築於轉位酶顯子 (exon) C 和D 間，而將轉位子之3 端建構於抗嘉磷賽之epsps ( 5-enolpyruvylshikimate-3-phosphate synthase；篩選標記基因 ) 顯子1和2 之間，完成之構築命名為COKC。透過誘導劑水楊酸處理，企圖使轉位子轉位 (transposition) 將兩端及其內部分轉位酶基因和部分epsps 基因片段切離，達到終止轉位酶基因和修飾之epsps 基因之功能。

關鍵字

轉位酶 ； epsps ； 可誘導轉位子 ； 篩選標記基因 ； 轉基因植物

並列摘要

Since the maize transposon Ac can relocate to a new location within the genome, it has beenused in removing selectable markers in transgenic plants. We previously developed an inducible transposon system to truncate a selectable marker in transgenic plants by locating one end of the transposon in the intron of the marker gene (glyphosate tolerant epsps gene). We have now improved upon this system by locating the other end of the transposon in the intron of the transposase gene, which is controlled by the inducible promoter (PR-1a). Treatment with salicylic acid induced transposition of this transposon, COKC, which led to both marker gene and transposase gene breakages in exons. The behavior of COKC was analyzed in singlecopy transgenic rice plants. We determined the expression of the modified transposase and epsps genes and the transposition events in transgenic plants. The COKC element thus exhibits potential as a tool to create ”marker-off” transgenic plants for woody or vegetatively propagated plants species.

並列關鍵字

Ac transposase ； epsps ； Inducible transposon ； Selectable marker ； Transgenic plants