College of Agronomy, Jiangxi Agricultural University, Nanchang 330045, China.
National Engineering Laboratory of Crop Stress Resistance Breeding, School of Life Sciences, Anhui Agricultural University, Hefei 230036, China.
Plant Physiol. 2024 Jun 28;195(3):2256-2273. doi: 10.1093/plphys/kiae195.
Fruit ripening is a complex process involving dynamic changes to metabolites and is controlled by multiple factors, including transcription factors (TFs). Several TFs are reportedly essential regulators of tomato (Solanum lycopersicum) fruit ripening. To evaluate the effects of specific TFs on metabolite accumulation during fruit ripening, we combined CRISPR/Cas9-mediated mutagenesis with metabolome and transcriptome analyses to explore regulatory mechanisms. Specifically, we generated various genetically engineered tomato lines that differed regarding metabolite contents and fruit colors. The metabolite and transcript profiles indicated that the selected TFs have distinct functions that control fruit metabolite contents, especially carotenoids and sugars. Moreover, a mutation to ELONGATED HYPOCOTYL5 (HY5) increased tomato fruit fructose and glucose contents by approximately 20% (relative to the wild-type levels). Our in vitro assay showed that HY5 can bind directly to the G-box cis-element in the Sugars Will Eventually be Exported Transporter (SWEET12c) promoter to activate expression, thereby modulating sugar transport. Our findings provide insights into the mechanisms regulating tomato fruit ripening and metabolic networks, providing the theoretical basis for breeding horticultural crops that produce fruit with diverse flavors and colors.
果实成熟是一个涉及代谢物动态变化的复杂过程,受多种因素控制,包括转录因子(TFs)。据报道,有几个 TFs 是番茄(Solanum lycopersicum)果实成熟的重要调节因子。为了评估特定 TFs 在果实成熟过程中对代谢物积累的影响,我们结合 CRISPR/Cas9 介导的诱变与代谢组学和转录组学分析来探索调控机制。具体来说,我们生成了各种具有不同代谢物含量和果实颜色的基因工程番茄系。代谢物和转录谱表明,所选 TFs 具有不同的功能,可控制果实代谢物含量,特别是类胡萝卜素和糖。此外,ELONGATED HYPOCOTYL5 (HY5) 的突变使番茄果实的果糖和葡萄糖含量增加了约 20%(相对于野生型水平)。我们的体外实验表明,HY5 可以直接结合 Sugars Will Eventually be Exported Transporter (SWEET12c) 启动子中的 G-box 顺式元件来激活表达,从而调节糖的运输。我们的研究结果为调控番茄果实成熟和代谢网络的机制提供了新的见解,为培育具有不同风味和颜色的园艺作物提供了理论基础。