Flower Research Laboratory, College of Forestry, Shandong Agricultural University, Taian 271018, China.
Int J Mol Sci. 2018 Dec 14;19(12):4057. doi: 10.3390/ijms19124057.
In this study, a gene with a full-length cDNA of 1422 bp encoding 473 amino acids, designated , was isolated from R. rugosa 'Zizhi' and then functionally characterized. RrGT2 transcripts were detected in various tissues and were proved that their expression patterns corresponded with anthocyanins accumulation. Functional verification of in R. rugosa was performed via VIGS. When was silenced, the Rosa plants displayed a pale petal color phenotype. The detection results showed that the expression of was significantly downregulated, which was consistent with the decrease of all anthocyanins; while the expression of six key upstream structural genes was normal. Additionally, the in vivo function of RrGT2 was investigated via its overexpression in tobacco. In transgenic tobacco plants expressing RrGT2, anthocyanin accumulation was induced in the flowers, indicating that RrGT2 could encode a functional GT protein for anthocyanin biosynthesis and could function in other species. The application of VIGS in transgenic tobacco resulted in the treated tobacco plants presenting flowers whose phenotypes were lighter in color than those of normal plants. These results also validated and affirmed previous conclusions. Therefore, we speculated that glycosylation of plays a crucial role in anthocyanin biosynthesis in R. rugosa.
在这项研究中，从 R. rugosa 'Zizhi' 中分离出一个全长为 1422bp、编码 473 个氨基酸的基因 ，并对其进行了功能表征。RrGT2 转录本在各种组织中均有检测到，并证明其表达模式与花色苷积累相对应。通过 VIGS 对 R. rugosa 中的 进行功能验证。当 沉默时，玫瑰植株表现出花瓣颜色变淡的表型。检测结果表明， 的表达显著下调，这与所有花色苷的减少一致；而六个关键上游结构基因的表达正常。此外，通过在烟草中过表达 RrGT2 研究了 RrGT2 的体内功能。在表达 RrGT2 的转基因烟草植物中，花色苷在花朵中积累，表明 RrGT2 可以编码一个功能性的 GT 蛋白，用于花色苷的生物合成，并可以在其他物种中发挥作用。VIGS 在转基因烟草中的应用导致处理过的烟草植物的花朵颜色比正常植物的花朵颜色更浅。这些结果也验证和肯定了之前的结论。因此，我们推测 糖基化在 R. rugosa 花色苷生物合成中起着关键作用。
