Wu Yanyan, Wu Sihui, Shi Yan, Jiang Libo, Yang Juxiang, Wang Xueqin, Zhu Kaijie, Zhang Hongyan, Zhang Jie
Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
College of Life Sciences and Medicine, Shandong University of Technology, Zibo 255000, Shandong, China.
Genomics. 2022 Nov;114(6):110513. doi: 10.1016/j.ygeno.2022.110513. Epub 2022 Oct 26.
As a worldwide major ornamental flower and a edible plant, lotus (Nelumbo nucifera) is also used as medicine and tea beverage. Here, transcriptome and metabolites of yellow (MLQS) and white (YGB) lotus cultivars during five key flower coloration stages were profiled. 2014 differentially expressed genes were detected with 11 carotenoids in lotus were identified for the first time. Then, regulatory networks between and within functional modules was reconstructed, and the correlation between module-metabolites and gene-metabolites was conducted within 3 core modules. 18 candidate genes related to the formation of yellow flower were screened out and a gene regulatory model for the flower color difference between MLQS and YGB were speculated as follows: The substrate competition between F3'H and F3'5'H and substrate specificity of FLS, together with differential expression of CCD4a and CCD4b were contribute to the differences in flavonoids and carotenoids. Besides, UGT73C2, UGT91C1-2 and SGTase, and regulation of UGTs by transcription factors PLATZ, MADS, NAC031, and MYB308 may also play a role in the upstream regulation. The following verification results indicated that functional differences existed in the coding sequences of NnCCD4b and promoters of NnCCD4a of MLQS and YGB. In all, this study preliminarily reveals the mechanism of yellow flower coloration in lotus and provides new ideas for the study of complex ornamental characters of other plants.
作为一种全球主要的观赏花卉和食用植物，莲花（Nelumbo nucifera）还被用作药物和茶饮料。在此，对黄色（MLQS）和白色（YGB）莲花品种在五个关键花色形成阶段的转录组和代谢产物进行了分析。首次检测到2014个差异表达基因，并鉴定出莲花中的11种类胡萝卜素。然后，重建了功能模块之间和内部的调控网络，并在3个核心模块内进行了模块-代谢产物和基因-代谢产物之间的相关性分析。筛选出18个与黄花形成相关的候选基因，并推测MLQS和YGB之间花色差异的基因调控模型如下：F3'H和F3'5'H之间的底物竞争以及FLS的底物特异性，以及CCD4a和CCD4b的差异表达导致了黄酮类化合物和类胡萝卜素的差异。此外，UGT73C2、UGT91C1-2和SGTase，以及转录因子PLATZ、MADS、NAC031和MYB308对UGTs的调控也可能在上游调控中发挥作用。以下验证结果表明，MLQS和YGB的NnCCD4b编码序列和NnCCD4a启动子存在功能差异。总之，本研究初步揭示了莲花黄花色形成的机制，并为其他植物复杂观赏性状的研究提供了新思路。
