Eggplant is rich in anthocyanins. R2R3-MYB transcription factors play a key role in the anthocyanin pathway. Low temperature is vital abiotic stress that affects the anthocyanin biosynthesis in plants. CBFs (C-repeat binding factors) act as central regulators in cold response. In this study, we found that SmCBF1, SmCBF2 and SmCBF3, via their C-terminal, physically interacted with SmMYB113, a key regulator of anthocyanin biosynthesis in eggplant. SmCBF2 and SmCBF3 upregulated the expression of SmCHS and SmDFR via a SmMYB113-dependent pathway. In addition, the transient expression assays demonstrated that co-infiltrating SmCBFs and SmMYB113 significantly improved the contents of anthocyanin and the expression levels of anthocyanin structural genes in tobacco. When SmTT8, a bHLH partner of SmMYB113, coexpressed with SmCBFs and SmMYB113, the anthocyanin contents were significantly enhanced compared with SmCBFs and SmMYB113. Furthermore, overexpression of SmCBF2 and SmCBF3 could facilitate the anthocyanin accumulation under cold conditions in Arabidopsis. Taken together, these results shed light on the functions of SmCBFs and potential mechanisms of low-temperature-induced anthocyanin biosynthesis in eggplant.

中文翻译：

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CBF通过与茄子（Solanum melongena L.）中的MYB113相互作用在花色苷生物合成中发挥作用。

茄子富含花青素。R2R3-MYB转录因子在花色苷途径中起关键作用。低温是至关重要的非生物胁迫，会影响植物中的花色苷生物合成。CBF（C重复结合因子）在寒冷反应中起中央调节器的作用。在这项研究中，我们发现SmCBF1，SmCBF2和SmCBF3通过它们的C末端与茄子花青素生物合成的关键调节剂SmMYB113物理相互作用。SmCBF2和SmCBF3通过SmMYB113依赖性途径上调SmCHS和SmDFR的表达。另外，瞬时表达分析表明，共渗入的SmCBFs和SmMYB113显着提高了烟草中花色苷的含量和花色苷结构基因的表达水平。当SmMYB113的bHLH伙伴SmTT8与SmCBF和SmMYB113共表达时，与SmCBFs和SmMYB113相比，花青素含量显着增加。此外，SmCBF2和SmCBF3的过表达可以促进拟南芥在寒冷条件下花色苷的积累。综上所述，这些结果揭示了SmCBF的功能以及低温诱导茄子花色苷生物合成的潜在机制。