A Malus domestica MdMYB10 transcription factor gene was previously used as visible marker for successful plant transformation. We combined the MdMYB10 transcription factor gene with a GFP gene to test its viability as a non-destructive, visual, double reporter system for functional promoter studies in transgenic strawberry plants. The GFP gene was fused to MdMYB10 to provide evidence for promoter activity in red colored cells of transformed plant tissue and to exclude artefacts resulting from stress response or due to other environmental cues. To test this system in a first approach, we evaluated the MdMYB10-GFP43 construct in transgenic strawberries in combination with two constitutive promoters of varying strength, the strong CaMV 35S promoter and a weak flavonoid 3'-hydroxylase (F3'H) promoter isolated from the ornamental plant Cosmos sulphureus. Agrobacterium tumefaciens mediated transformation of Fragaria vesca with the MdMYB10-GFP43 construct combined with the CaMV 35S or F3'H promoter sequences resulted in the regeneration of 6 and 4 transgenic lines, respectively. A complete red coloration of all plant organs was found in four out of six transgenic lines harboring the 35S-MdMYB10-GFP43 construct. Less red coloration of plant organs was found for lines transformed with the F3'H-MdMYB10-GFP43 construct. The MdMYB10 gene shows only limited suitability as a reporter gene for promoter studies in strawberries because weak promoter activity is difficult to distinguish, particularly in tissues showing a strongly colored background such as green leaves. GFP specific fluorescence signals were detectable neither in tissue strongly expressing MdMYB10 nor in green tissue of any transgenic line. The reason for this remained unclear but it can be excluded that it was due to incorrect splicing.

中文翻译：

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评估MdMYB10 / GFP43融合基因是否适合用作草莓（Ruggen）的启动子研究中的报告基因。

以前将家蝇（Malus domestica）MdMYB10转录因子基因用作成功植物转化的可见标记。我们将MdMYB10转录因子基因与GFP基因结合起来，以测试其作为转基因草莓植物中功能启动子研究的非破坏性，可视化，双重报告系统的可行性。GFP基因与MdMYB10融合在一起，为转化植物组织的红色细胞中启动子活性提供证据，并排除了因胁迫反应或其他环境因素而导致的假象。为了以第一种方法测试该系统，我们评估了转基因草莓中MdMYB10-GFP43构建体与两个强度不同的组成型启动子，强CaMV 35S启动子和弱类黄酮3'-羟化酶（F3' H）从观赏植物波斯菊硫脲分离的启动子。用MdMYB10-GFP43构建体与CaMV 35S或F3'H启动子序列结合的根癌农杆菌介导的草莓转化，分别导致6和4个转基因系的再生。在具有35S-MdMYB10-GFP43构建体的6个转基因品系中，有4个中的所有植物器官都被完全染成红色。对于用F3'H-MdMYB10-GFP43构建体转化的品系，发现植物器官的红色较少。MdMYB10基因在草莓中作为启动子研究的报告基因仅显示出有限的适用性，因为难以区分弱的启动子活性，特别是在背景色强烈的组织（例如绿叶）中。在强烈表达MdMYB10的组织或任何转基因系的绿色组织中均未检测到GFP特异性荧光信号。其原因尚不清楚，但可以排除由于错误的拼接造成的原因。