Transcriptomic Analysis of Paeonia delavayi Wild Population Flowers to Identify Differentially Expressed Genes Involved in Purple-Red and Yellow Petal Pigmentation.
Transcriptomic Analysis of Paeonia delavayi Wild Population Flowers to Identify Differentially Expressed Genes Involved in Purple-Red and Yellow Petal Pigmentation.
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DOI：
10.1371/journal.pone.0135038
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Miao K
中科院分区：
文献类型：
--
作者：
Shi Q;Zhou L;Wang Y;Li K;Zheng B;Miao K
牡丹是我国著名的传统观赏植物。滇牡丹是我国西南地区特有的花色品种，是花色育种的宝贵遗传资源，引起了研究者的极大兴趣。然而，目前对牡丹花色素形成的分子机制的了解有限，阻碍了牡丹新花色基因工程的开展。在这项研究中，我们进行了一个大规模的转录组分析的基础上Illumina HiSeq测序的cDNA文库产生的黄色和紫红色的P. delavayi花瓣。通过从头组装共获得90，202个unigenes，平均长度为721 nt。使用Blastx，发现44，811个单基因（49.68%）与NR，NT和Swiss-Prot数据库中的加入物具有显著相似性。我们还检查了COG，GO和KEGG注释，以更好地理解这些unigenes的功能。对两个数字转录组的进一步分析显示，6，855个unigenes在黄色和紫红色花瓣之间差异表达，其中3，430个上调，3，425个下调。根据RNA-Seq数据和qRT-PCR分析，我们推测F3 H、DFR、ANS和3GT等4个上调的关键结构基因可能在紫红色花瓣色素形成中起重要作用，而THC 2 'GT、CHI和FNS II的高共表达则保证了色素的积累，从而促进了黄色的形成。我们还发现了50个可能参与类黄酮生物合成的差异表达转录因子。该研究首次报道了P. delavayi的遗传信息。大量的基因序列产生的转录组测序和候选基因的识别，使用路径映射和表达谱将提供一个宝贵的资源，为未来的关联研究，旨在更好地了解牡丹花色素沉着的分子机制。
Tree peony (Paeonia suffruticosa Andrews) is a very famous traditional ornamental plant in China. P. delavayi is a species endemic to Southwest China that has aroused great interest from researchers as a precious genetic resource for flower color breeding. However, the current understanding of the molecular mechanisms of flower pigmentation in this plant is limited, hindering the genetic engineering of novel flower color in tree peonies. In this study, we conducted a large-scale transcriptome analysis based on Illumina HiSeq sequencing of cDNA libraries generated from yellow and purple-red P. delavayi petals. A total of 90,202 unigenes were obtained by de novo assembly, with an average length of 721 nt. Using Blastx, 44,811 unigenes (49.68%) were found to have significant similarity to accessions in the NR, NT, and Swiss-Prot databases. We also examined COG, GO and KEGG annotations to better understand the functions of these unigenes. Further analysis of the two digital transcriptomes revealed that 6,855 unigenes were differentially expressed between yellow and purple-red flower petals, with 3,430 up-regulated and 3,425 down-regulated. According to the RNA-Seq data and qRT-PCR analysis, we proposed that four up-regulated key structural genes, including F3H, DFR, ANS and 3GT, might play an important role in purple-red petal pigmentation, while high co-expression of THC2'GT, CHI and FNS II ensures the accumulation of pigments contributing to the yellow color. We also found 50 differentially expressed transcription factors that might be involved in flavonoid biosynthesis. This study is the first to report genetic information for P. delavayi. The large number of gene sequences produced by transcriptome sequencing and the candidate genes identified using pathway mapping and expression profiles will provide a valuable resource for future association studies aimed at better understanding the molecular mechanisms underlying flower pigmentation in tree peonies.