Background Jatropha curcas L., a perennial oilseed plant, is considered as a promising feedstock for biodiesel production. Genetic modification of flowering characteristics is critical for Jatropha breeding. However, analysis of floral-specific promoters in Jatropha is limited. Methods In this study, we isolated the Jatropha ortholog of TM6 (JcTM6) gene from Jatropha flower cDNA library and detected the expression pattern of JcTM6 gene by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). We isolated a 1.8-kb fragment from the 5’ region of the JcTM6 gene and evaluated its spatiotemporal expression pattern in Arabidopsis using the β-glucuronidase (GUS) reporter gene and Arabidopsis ATP/ADP isopentenyltransferase 4 (AtIPT4) gene, respectively. Results JcTM6 was identified as a flower-specific gene in Jatropha. As expected, JcTM6 promoter was only active in transgenic Arabidopsis flowers with the strongest activity in stamens. Moreover, JcTM6:AtIPT4 transgenic Arabidopsis showed a phenotype of large flowers without any alterations in other organs. Furthermore, deletion of the region from –1,717 to –876 bp resulted in the disappearance of promoter activity in stamens but an increase in promoter activity in young leaves, sepals, and petals. Deletion analysis suggests that the –1,717- to –876-bp promoter fragment contains regulatory elements that confer promoter activity in stamens and inhibit activity in young leaves, sepals, and petals.

中文翻译：

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番茄 MADS-box 基因 6 (JcTM6) 启动子的麻风树直系同源物在拟南芥中表现出花特异性活性

背景 麻风树是一种多年生油籽植物，被认为是一种很有前途的生物柴油生产原料。开花特性的基因改造对麻风树育种至关重要。然而，对麻风树花特异性启动子的分析是有限的。方法在本研究中，我们从麻风树花cDNA文库中分离出麻风树TM6（JcTM6）基因的直系同源物，并通过定量逆转录聚合酶链反应（qRT-PCR）检测JcTM6基因的表达模式。我们从 JcTM6 基因的 5' 区域分离了一个 1.8-kb 片段，并分别使用 β-葡萄糖醛酸酶 (GUS) 报告基因和拟南芥 ATP/ADP 异戊烯基转移酶 4 (AtIPT4) 基因评估了其在拟南芥中的时空表达模式。结果 JcTM6被鉴定为麻风树花特异性基因。正如预期的那样，JcTM6 启动子仅在转基因拟南芥花中具有活性，在雄蕊中活性最强。此外，JcTM6:AtIPT4转基因拟南芥显示出大花的表型，其他器官没有任何改变。此外，该区域从–1,717 到–876 bp 的缺失导致雄蕊中的启动子活性消失，但幼叶、萼片和花瓣中的启动子活性增加。缺失分析表明，–1,717 至 –876-bp 启动子片段包含调节元件，这些元件赋予雄蕊中的启动子活性并抑制幼叶、萼片和花瓣中的活性。将该区域从–1,717 bp 删除到–876 bp 导致雄蕊中的启动子活性消失，但幼叶、萼片和花瓣中的启动子活性增加。缺失分析表明，–1,717 至 –876-bp 启动子片段包含调节元件，这些元件赋予雄蕊中的启动子活性并抑制幼叶、萼片和花瓣中的活性。将该区域从–1,717 bp 删除到–876 bp 导致雄蕊中的启动子活性消失，但幼叶、萼片和花瓣中的启动子活性增加。缺失分析表明，–1,717 至 –876-bp 启动子片段包含调节元件，这些元件赋予雄蕊中的启动子活性并抑制幼叶、萼片和花瓣中的活性。