High-efficiency improvement of transgenic torenia flowers by ion beam irradiation
High-efficiency improvement of transgenic torenia flowers by ion beam irradiation
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DOI：
10.5511/plantbiotechnology.25.81
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发表时间：
2008-03
影响因子：
1.6
通讯作者：
K. Sasaki;R. Aida;T. Niki;H. Yamaguchi;T. Narumi;T. Nishijima;Y. Hayashi;H. Ryuto;N. Fukunishi;T. Abe;N. Ohtsubo
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文献类型：
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作者：
K. Sasaki;R. Aida;T. Niki;H. Yamaguchi;T. Narumi;T. Nishijima;Y. Hayashi;H. Ryuto;N. Fukunishi;T. Abe;N. Ohtsubo
为了缩短培育转基因观赏植物所需的时间，优化转基因观赏植物的风险-成本/收益比，我们对野生型和转基因的Torenia ournieri Lind进行了重离子束辐照。简历通过控制编码查尔酮合成酶(CHS)和二氢黄酮醇-4-还原酶(DFR)的两个花青素生物合成相关基因来改变花瓣颜色和花纹的‘冠紫’植物。用12C6�和20Ne 10�的离子束照射来自野生型和5个转基因品系的11,500个叶盘，然后对3,200多个再生植株进行了可见表型的研究。全程照射后突变率平均为10.4%，初筛最高突变率为44.2%(20Ne、30Gy)。突变表型主要在花中观察到，并且在颜色和形状上表现出很大的变异。转基因植株在花瓣颜色和着色模式上的突变率高于野生型植株，而在花瓣形状和花冠发散方面的突变率在两种植物群体中几乎相同。转化子突变体的花瓣颜色突变谱明显比野生型植株宽。在这些突变体中，1个B类基因缺失突变体被作为进一步研究花表型控制的模式案例。TfGLO基因在该品系中的表达受到抑制，可能是由于上游信号转导功能障碍所致。我们认为，基因工程和离子束辐照的结合在短时间内极大地促进了农业生物学性状和商业性状的改良。我们还讨论了观察到的高频特征变化和基于突变的有用基因鉴定方法。
To shorten the time required for breeding and optimize the risk-cost/benefit ratio of genetically modified ornamental plants, we applied heavy-ion beam irradiation to wild-type and genetically modified torenia (Torenia fournieri Lind. CV. 'Crown Violet' plants in which petal color and pattern had been modified by controlling two anthocyanin biosynthesis-related genes encoding chalcone synthase (CHS ) and dihydroflavonol-4-reductase (DFR). Ion beams of 12 C 6� and 20 Ne 10� were applied to 11,500 leaf disks from wild type and five transgenic lines, and over 3,200 regenerated flowering plants were then investigated for visible phenotypes. The mutation rate after whole irradiation averaged 10.4%, and the maximum rate in the initial screening was 44.2% ( 20 Ne, 30 Gy). Mutant phenotypes were observed mainly in flowers and showed wide variation in color and shape. Mutation efficiencies for petal color and coloration pattern were higher in transgenic plants than in wild-type plants, while those for petal shape and corolla divergence were almost equivalent in the two plant groups. Mutation spectrums in petal color in transformant-based mutants were obviously wider than those in wild- type plants. Among these mutants, a class B gene-deficient mutant was investigated as a model case for further study to facilitate the control of flower phenotype. Expression of the TfGLO gene was found to be repressed in this line, probably due to dysfunctioning of the upstream signaling. We propose that the combination of genetic engineering and ion beam irradiation greatly facilitates improvement of agrobiological and commercial traits within a short period. We also discuss characteristic changes observed at high frequency in torenia flowers and the mutant-based approach to the identification of useful genes.