State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430026, China; Research Center of Buckwheat Industry Technology, Guizhou Normal University, Guiyang, 550001, China.
State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430026, China.
Plant Physiol Biochem. 2023 May;198:107675. doi: 10.1016/j.plaphy.2023.107675. Epub 2023 Mar 31.
Bicolor flower lotus is rare with high ornamental value. During the long history of breeding and artificial selection, a very famous lotus cultivar 'Da Sajin' with red and white picotee bicolor petals were obtained. In order to reveal the mechanism underlying the formation of its picotee bicolor pattern in the petal, an integrative metabolomics and proteomics analyses were conducted between red and white parts of its petals. The results showed that the defect of anthocyanidin 3-O-glucosyltransferases (UFGTs) accumulation resulted in the failure of the glycosylation of anthocyanidin, the last step of anthocyanin biosynthesis in white part of the petals. And proteomic data and biochemical analysis showed that the defect of UFGTs accumulation is not related to their transcription, but because of their degradation. Function of one differentially accumulated NnUFGT were proven being involved in anthocyanin biosynthesis through both in-vitro enzyme assay and in-vivo transgenic analyses. This regulation on the protein accumulation of structural genes in anthocyanin biosynthesis was not explored in any other plants, and hence supposed to be a novel mechanism for the formation of picotee bicolor pattern flower. The results not only provide some new insights into the understanding of lotus flower coloration, but also might assist the breeding of flower lotus.
双色莲花稀少，具有很高的观赏价值。在长期的培育和人工选择过程中，培育出了一种非常著名的荷花品种“大洒锦”，它具有红白双色的镶边花瓣。为了揭示其花瓣镶边双色图案形成的机制，对其花瓣的红色和白色部分进行了综合代谢组学和蛋白质组学分析。结果表明，由于类黄酮 3-O-葡萄糖基转移酶（UFGTs）的积累缺陷，导致了花瓣白色部分中类黄酮生物合成的最后一步——花青素的糖基化失败。蛋白质组学数据和生化分析表明，UFGTs 积累的缺陷与其转录无关，而是由于它们的降解。通过体外酶活性测定和体内转基因分析，证明一个差异积累的 NnUFGT 的功能参与了花青素的生物合成。在其他任何植物中都没有探索过这种对花青素生物合成结构基因蛋白积累的调控，因此推测这是形成双色镶边图案花朵的一种新机制。该研究结果不仅为理解莲花的花色提供了一些新的见解，而且可能有助于荷花的培育。
