Shanghai Key Laboratory of Agricultural Genetics and Breeding, Agro-Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, 2901 Beidi Rd, Shanghai 201106, PR China.
Shanghai Key Laboratory of Agricultural Genetics and Breeding, Agro-Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, 2901 Beidi Rd, Shanghai 201106, PR China.
Plant Sci. 2021 Feb;303:110796. doi: 10.1016/j.plantsci.2020.110796. Epub 2020 Dec 10.
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.
类黄酮是小分子次生代谢物，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着关键作用。本研究从番茄中分离到一个 R2R3-MYB 转录因子基因 SlMYB14，并对其进行了特征分析。SlMYB14 定位于细胞核，作为酵母中的转录激活因子。SlMYB14 的表达可被茉莉酸甲酯、创伤和 ABA 诱导。SlMYB14 在茉莉酸信号通路中位于 SlMYC2 下游。在番茄中，SlMYB14 受 CaMV35S 启动子的控制过表达，导致类黄酮的积累增加。RNA-seq 分析显示，转 SlMYB14 基因番茄植株中与类黄酮生物合成相关的几个结构基因的转录水平上调。凝胶迁移实验证实 SlMYB14 蛋白可结合 SlPAL 基因的启动子区域。研究还发现，过表达 SlMYB14 可提高转基因植物对 2,4,6-三氯苯酚（2,4,6-TCP）的耐受性，2,4,6-TCP 是一种环境有机污染物，可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控，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。
