2017年4月21日，植物學國際期刊《Frontiers in plantscience》雜誌在線發表了中國農業科學院蔬菜花卉研究所百合課題組明軍研究員的一篇研究論文，研究揭示了雙色百合花形成的關鍵分子機理，將為花色的人工調控及分子改良提供理論依據。博士研究生徐雷鋒為第一作者，明軍研究員為通訊作者。
雙色百合花是指在同一片花被片上顯現兩種不同的花色，與單色花相比具有更豐富的花色及其奇特的色彩變化，觀賞價值更高，有可能在吸引昆蟲方面也更具效率。百合品種小飛碟 (Tiny Padhye) 雙色花被片發育的過程中，花被片下部逐漸由綠色變為紫紅色，而上部由綠色變為白色。這類百合雙色花形成的分子機理在花色研究領域鮮見報道。
該研究運用代謝組學、比較轉錄組學和分子生物學相結合的手段對雙色百合花形成的分子機理進行了研究。雙色百合花的紫色部位的成色物質主要成分為矢車菊素-3-芸香糖苷。表達譜分析表明，花青素苷合成基因在花被片下部特異協同表達導致花青素苷特異地積累於花被片下部，而在花被片上部不表達。百合花被片中葉綠素含量逐漸下降的原因是，隨著花被片的發育，葉綠素合成相關結構基因在花被片上下部的表達量均逐漸下降，而葉綠素降解相關結構基因的表達量迅速上升。通過WGCNA分析，參與調控百合花被片中花青素苷合成通路以及葉綠素代謝通路的候選轉錄因子也得以鑑定。
原文鏈接：
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 expressionlevel 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：明軍 點擊：次