Flavonoids are small molecular secondary metabolites, which have a variety of biological functions. Transcriptional regulations of key enzyme genes play critical roles in the flavonoid biosynthesis. In this study, an R2R3-MYB transcription factor gene, SlMYB14, was isolated from tomato and characterized. The nucleus-localized SlMYB14 functions as a transcriptional activator in yeast. The expression of SlMYB14 could be induced by methyl jasmonic acid, wounding and ABA. SlMYB14 works downstream of SlMYC2 in the jasmonate signaling pathway. Overexpression of SlMYB14 under the control of CaMV35S promoter in tomato led to increased accumulation of flavonoids. RNA-sequencing analysis revealed that the transcript levels of several structural genes associated with flavonoid biosynthesis were up-regulated in transgenic tomato plants. Gel-shift assays confirmed that SlMYB14 protein could bind to the promoter regions of SlPAL genes. It was also found that overexpression of SlMYB14 improved the tolerance of transgenic plants to 2,4,6-trichlorophenol (2,4,6-TCP), an environmental organic pollutant which could cause serious oxidative damage to plant. These results suggest that SlMYB14 participates in the regulation of flavonoid biosynthesis and might play a role in maintaining reactive oxygen species homeostasis in plant. SlMYB14 gene also has the potential to contribute to the phytoremediation of 2,4,6-TCP-contaminated soils.

中文翻译：

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SlMYB14 促进类黄酮积累并赋予番茄对 2,4,6-三氯苯酚更高的耐受性

黄酮类化合物是小分子次生代谢产物，具有多种生物学功能。关键酶基因的转录调控在类黄酮生物合成中起关键作用。在这项研究中，从番茄中分离并表征了 R2R3-MYB 转录因子基因 SlMYB14。细胞核定位的 SlMYB14 在酵母中充当转录激活剂。SlMYB14的表达可以被甲基茉莉酸、创伤和ABA诱导。SlMYB14 在茉莉酸信号通路中 SlMYC2 的下游起作用。SlMYB14 在番茄中 CaMV35S 启动子控制下的过表达导致类黄酮积累增加。RNA 测序分析表明，与类黄酮生物合成相关的几种结构基因的转录水平在转基因番茄植物中上调。凝胶迁移试验证实 SlMYB14 蛋白可以与 SlPAL 基因的启动子区域结合。还发现 SlMYB14 的过表达提高了转基因植物对 2,4,6-三氯苯酚 (2,4,6-TCP) 的耐受性，2,4,6-TCP 是一种可能对植物造成严重氧化损伤的环境有机污染物。这些结果表明 SlMYB14 参与了类黄酮生物合成的调节，并可能在维持植物活性氧稳态中发挥作用。SlMYB14 基因也有可能有助于 2,4,6-TCP 污染土壤的植物修复。一种环境有机污染物，会对植物造成严重的氧化损伤。这些结果表明 SlMYB14 参与了类黄酮生物合成的调节，并可能在维持植物活性氧稳态中发挥作用。SlMYB14 基因也有可能有助于 2,4,6-TCP 污染土壤的植物修复。一种环境有机污染物，会对植物造成严重的氧化损伤。这些结果表明 SlMYB14 参与了类黄酮生物合成的调节，并可能在维持植物活性氧稳态中发挥作用。SlMYB14 基因也有可能有助于 2,4,6-TCP 污染土壤的植物修复。