Front Plant SCI:农科院蔬菜所明军研究组揭示双色百合花形成的分子
2017年4月21日，植物学国际期刊《Frontiers in plant science》杂志在线发表了中国农业科学院蔬菜花卉研究所百合课题组明军研究员的一篇研究论文，研究揭示了双色百合花形成的关键分子机理，将为花色的人工调控及分子改良提供理论依据。博士研究生徐雷锋为第一作者，明军研究员为通讯作者。
双色百合花是指在同一片花被片上显现两种不同的花色，与单色花相比具有更丰富的花色及其奇特的色彩变化，观赏价值更高，有可能在吸引昆虫方面也更具效率。百合品种小飞碟 (Tiny Padhye) 双色花被片发育的过程中，花被片下部逐渐由绿色变为紫红色，而上部由绿色变为白色。这类百合双色花形成的分子机理在花色研究领域鲜见报道。
该研究运用代谢组学、比较转录组学和分子生物学相结合的手段对双色百合花形成的分子机理进行了研究。双色百合花的紫色部位的成色物质主要成分为矢车菊素-3-芸香糖苷。表达谱分析表明，花青素苷合成基因在花被片下部特异协同表达导致花青素苷特异地积累于花被片下部，而在花被片上部不表达。百合花被片中叶绿素含量逐渐下降的原因是，随着花被片的发育，叶绿素合成相关结构基因在花被片上下部的表达量均逐渐下降，而叶绿素降解相关结构基因的表达量迅速上升。通过WGCNA分析，参与调控百合花被片中花青素苷合成通路以及叶绿素代谢通路的候选转录因子也得以鉴定。
原文链接：
Spatiotemporal Transcriptome Analysis Provides Insights into Bicolor Tepal Development in Lilium “Tiny Padhye”
原文摘要：
The bicolor Asiatic hybrid lily cultivar “Tiny Padhye” is an attractive variety because of its unique color pattern. During its bicolor tepal development, the upper tepals undergo a rapid color change from green to white, while the tepal bases change from green to purple. However, the molecular mechanisms underlying these changes remain largely uncharacterized. To systematically investigate the dynamics of the lily bicolor tepal transcriptome during development, we generated 15 RNA-seq libraries from the upper tepals (S2-U) and basal tepals (S1-D, S2-D, S3-D, and S4-D) of Lilium “Tiny Padhye.” Utilizing the Illumina platform, a total of 295,787 unigenes were obtained from 713.12 million high-quality paired-end reads. A total of 16,182 unigenes were identified as differentially expressed genes during tepal development. Using Kyoto Encyclopedia of Genes and Genomes pathway analysis, candidate genes involved in the anthocyanin biosynthetic pathway (61 unigenes), and chlorophyll metabolic pathway (106 unigenes) were identified. Further analyses showed that most anthocyanin biosynthesis genes were transcribed coordinately in the tepal bases, but not in the upper tepals, suggesting that the bicolor trait of “Tiny Padhye” tepals is caused by the transcriptional regulation of anthocyanin biosynthetic genes. Meanwhile, the high expression level of chlorophyll degradation genes and low expression level of chlorophyll biosynthetic genes resulted in the absence of chlorophylls from “Tiny Padhye” tepals after flowering. Transcription factors putatively involved in the anthocyanin biosynthetic pathway and chlorophyll metabolism in lilies were identified using a weighted gene co-expression network analysis and their possible roles in lily bicolor tepal development were discussed. In conclusion, these extensive transcriptome data provide a platform for elucidating the molecular mechanisms of bicolor tepals in lilies and provide a basis for similar research in other closely related species.
作者：明军
