Identification of r mutations conferring white flowers in the Japanese morning glory (Ipomoea nil)
Identification of r mutations conferring white flowers in the Japanese morning glory (Ipomoea nil)
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DOI：
10.1007/s10265-008-0202-8
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发表时间：
2009-03-01
影响因子：
2.8
通讯作者：
Iida, Shigeru
中科院分区：
文献类型：
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作者：
Hoshino, Atsushi;Park, Kyeung-Il;Iida, Shigeru
野生型日本牵牛花[iomoea nil (L.)]罗斯。]的花是蓝色的，茎是红色的，而自发突变体的花是白色的，茎是绿色的。我们已经确定了两个r突变r1-1和r1-2，它们是由tpn1相关的DNA转座元件Tpn3 （5.6 kb）和Tpn6 （4.7 kb）分别插入到负责花和茎色素沉着的CHS-D基因的一个独特内含子中引起的。Tpn3和Tpn6都属于En/Spm或CACTA超家族，是缺乏转座酶基因的非自主元件，但包含不相关的细胞DNA片段，包括外显子和内含子。有趣的是，r1-2在r1-1的Tpn3整合位点上有一个额外的4 bp插入，可能是Tpn3切除引起的足迹。这一结果加强了之前的观点，即Tpn1及其近缘基因是水稻各种重要花学性状产生的主要自发诱变剂。由于I. nil具有广泛的遗传研究历史，经典自发突变的分子鉴定也将有助于重新解释丰富的经典遗传数据。
The wild-type Japanese morning glory [Ipomoea nil (L.) Roth.] exhibits blue flowers with red stems, and spontaneous r mutants display white flowers with green stems. We have identified two r mutations, r1-1 and r1-2, that are caused by insertions of Tpn1-related DNA transposable elements, Tpn3 (5.6 kb) and Tpn6 (4.7 kb), respectively, into a unique intron of the CHS-D gene, which is responsible for flower and stem pigmentation. Both Tpn3 and Tpn6, which belong to the En/Spm or CACTA superfamily, are nonautonomous elements lacking transposase genes but containing unrelated cellular DNA segments including exons and introns. Interestingly, r1-2 contains an additional 4-bp insertion at the Tpn3 integration site in r1-1, presumably a footprint caused by the excision of Tpn3. The results strengthen the previous notion that Tpn1 and its relatives are major spontaneous mutagens for generating various floriculturally important traits in I. nil. Since I. nil has an extensive history of genetic studies, molecular identification of classical spontaneous mutations would also facilitate reinterpretation of the abundant classical genetic data available.