Qian Ting, Wang Xiaoshan, Liu Jingjing, Shi Mengyun, Zhao Jing, Sun Peipei, Zheng Guanghui, Fang Congbing, Xie Xingbin
School of Horticulture, Anhui Agricultural University, Hefei, 230036, China.
School of Horticulture, Anhui Agricultural University, Hefei, 230036, China.
Plant Physiol Biochem. 2023 Oct;203:108037. doi: 10.1016/j.plaphy.2023.108037. Epub 2023 Sep 14.
Anthocyanins are important health-promoting flavonoid compounds that substantially contribute to fruit quality. Anthocyanin biosynthesis and most regulatory mechanisms are relatively well understood. However, the functions of anthocyanin transport genes in strawberry fruit remain unclear. In this study, a gene encoding an ATP-binding cassette (ABC) protein of type C, ABCC8, was isolated from strawberry fruits. qRT-PCR analysis demonstrated that the transcript levels of FvABCC8 were the highest and were strongly correlated with anthocyanin accumulation during strawberry fruit ripening. Transient overexpression and RNAi of FvABCC8 led to an increase and decrease in anthocyanin content in strawberry fruits, respectively. Moreover, the ABCC8 promoter was activated by MYB and bHLH transcription factors MYB10, bHLH33, and MYC1. Sucrose enhanced anthocyanin accumulation in FvABCC8-overexpressing Arabidopsis, particularly at higher concentrations. FvABCC8-overexpressing lines were less sensitive to ABA during seed germination and seedling development. These results suggest that strawberry vacuolar anthocyanin transport may be mediated by the ABCC transporter ABCC8, the expression of which may be regulated by transcription factors MYB10, bHLH33, and MYC1.
花青素是重要的具有促进健康作用的类黄酮化合物，对果实品质有重要贡献。花青素生物合成及其大多数调控机制已得到较好理解。然而，花青素转运基因在草莓果实中的功能仍不清楚。在本研究中，从草莓果实中分离出一个编码C型ATP结合盒（ABC）蛋白的基因ABCC8。qRT-PCR分析表明，FvABCC8的转录水平在草莓果实成熟过程中最高，且与花青素积累密切相关。FvABCC8的瞬时过表达和RNA干扰分别导致草莓果实中花青素含量增加和减少。此外，ABCC8启动子被MYB和bHLH转录因子MYB10、bHLH33和MYC1激活。蔗糖增强了过表达FvABCC8的拟南芥中的花青素积累，尤其是在较高浓度下。过表达FvABCC8的株系在种子萌发和幼苗发育过程中对ABA的敏感性较低。这些结果表明，草莓液泡花青素转运可能由ABCC转运蛋白ABCC8介导，其表达可能受转录因子MYB10、bHLH33和MYC1调控。
