Production of red-flowered plants by genetic engineering of multiple flavonoid biosynthetic genes
Production of red-flowered plants by genetic engineering of multiple flavonoid biosynthetic genes
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DOI：
10.1007/s00299-007-0401-0
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发表时间：
2007-11-01
影响因子：
6.2
通讯作者：
Nishihara, Masahiro
中科院分区：
文献类型：
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作者：
Nakatsuka, Takashi;Abe, Yoshiko;Nishihara, Masahiro
在一些花卉植物中，橘色到红色的花很难用常规育种技术培育出来。这是由于在花中缺乏使橙色变为红色的天竺葵苷的形成。此前已有研究报道，在矮牵牛中引入具有不同底物特异性的外源二氢黄酮醇4-还原酶（DFR）可以产生砖红色的花，而矮牵牛的色素不会自然积累。然而，由于这些实验使用了双氢山奈酚（DHK）积累突变体作为转化宿主，因此该策略不能直接应用于其他花艺植物。因此，本研究试图以烟草为模式植物，通过抑制两个内源基因和表达一个外源基因来培育红花植株。我们利用嵌合RNAi构建抑制黄酮醇合成酶（FLS）和类黄酮3′-羟化酶（f3′-h）两个基因和非洲菊DFR基因的表达，以促进烟草花中天竺苷色素的积累。经高效液相色谱分析证实，我们成功地生产出了含有大量额外的天竺葵苷的红花烟草植株。在转基因植株中，黄酮醇含量如预期的那样降低，但未达到完全抑制。表达分析还表明，两个靶基因的减少与外源基因的表达同时发生。这些结果表明，如果载体结构设计得当，可以通过多基因调控而不使用突变体实现花色修饰。
Orange- to red-colored flowers are difficult to produce by conventional breeding techniques in some floricultural plants. This is due to the deficiency in the formation of pelargonidin, which confers orange to red colors, in their flowers. Previous researchers have reported that brick-red colored flowers can be produced by introducing a foreign dihydroflavonol 4-reductase (DFR) with different substrate specificity in Petunia hybrida, which does not accumulate pelargonidin pigments naturally. However, because these experiments used dihydrokaempferol (DHK)-accumulated mutants as transformation hosts, this strategy cannot be applied directly to other floricultural plants. Thus in this study, we attempted to produce red-flowered plants by suppressing two endogenous genes and expressing one foreign gene using tobacco as a model plant. We used a chimeric RNAi construct for suppression of two genes (flavonol synthase [FLS] and flavonoid 3'-hydroxylase [F3'H]) and expression of the gerbera DFR gene in order to accumulate pelargonidin pigments in tobacco flowers. We successfully produced red-flowered tobacco plants containing high amounts of additional pelargonidin as confirmed by HPLC analysis. The flavonol content was reduced in the transgenic plants as expected, although complete inhibition was not achieved. Expression analysis also showed that reduction of the two-targeted genes and expression of the foreign gene occurred simultaneously. These results demonstrate that flower color modification can be achieved by multiple gene regulation without use of mutants if the vector constructs are designed resourcefully.