He Yan, Wang Yu, Zhang Mengzhuo, Liu Guangsen, Tian Cong, Xu Xiangbin, Pan Yonggui, Shi Xuequn, Zhang Zhengke, Meng Lanhuan
School of Food Science and Engineering, Hainan University, Haikou, China.
Key Laboratory of Food Nutrition and Functional Food of Hainan Province, Haikou, China.
Front Nutr. 2022 Dec 22;9:1062006. doi: 10.3389/fnut.2022.1062006. eCollection 2022.
Extensive data have demonstrated that carotenoid accumulation in tomato fruit is influenced by environmental cues and hormonal signals. However, there is insufficient information on the mechanism of its transcriptional regulation, as many molecular roles of carotenoid biosynthetic pathways remain unknown. In this work, we found that the silence of the BEL1-like family transcription factor (TF) BEL1-LIKE HOMEODOMAIN 11 (SlBEL11) enhanced carotenoid accumulation in virus induced gene silencing (VIGS) analysis. In its RNA interference (RNAi) transgenic lines, a significant increase in the transcription level for the lycopene beta cyclase 2 () gene was detected, which encoded a key enzyme located at the downstream branch of the carotenoid biosynthetic pathway. In Electrophoretic mobility shift assay (EMSA), SlBEL11 protein was confirmed to bind to the promoter of gene. In addition, the dual-luciferase reporter assay showed its intrinsic transcriptional repression activity. Collectively, our findings added a new member to the carotenoid transcriptional regulatory network and expanded the functions of the SlBEL11 transcription factor.
大量数据表明，番茄果实中类胡萝卜素的积累受环境线索和激素信号的影响。然而，关于其转录调控机制的信息不足，因为类胡萝卜素生物合成途径的许多分子作用仍不清楚。在这项研究中，我们发现，在病毒诱导基因沉默（VIGS）分析中，BEL1样家族转录因子（TF）BEL1-LIKE HOMEODOMAIN 11（SlBEL11）的沉默增强了类胡萝卜素的积累。在其RNA干扰（RNAi）转基因系中，检测到番茄红素β环化酶2（）基因的转录水平显著增加，该基因编码一种位于类胡萝卜素生物合成途径下游分支的关键酶。在电泳迁移率变动分析（EMSA）中，证实SlBEL11蛋白与基因的启动子结合。此外，双荧光素酶报告基因分析显示了其内在的转录抑制活性。总的来说，我们的研究结果为类胡萝卜素转录调控网络增加了一个新成员，并扩展了SlBEL11转录因子的功能。
