Data from: De novo assembly and characterization of leaf and floral transcriptomes of the hybridizing bromeliad species (Pitcairnia spp.) adapted to Neotropical Inselbergs

We present the leaf and floral transcriptomes of two hybridizing bromeliad species that differ in their major pollinator systems. Here we identified candidate genes responsible for pollinator attraction and reproductive isolation in these two species. We searched for candidate genes involved in floral traits, such as color. Approximately 34 Gbp of cDNA sequence data were produced from both tissues and species, resulting in a total of 424,506,914 raw reads. The de novo-assembled transcriptomes consisted of a total of 263,955 contigs, further clustered into 110,977 unigenes. Over 58% of the unigenes were functionally annotated and assigned to one or more Gene Ontology terms. The transcriptomes revealed 144 unique transcripts that encode key enzymes in the flavonoid and anthocyanin biosynthesis pathways. The domain/family annotation and phylogenetic analysis allowed us to infer, by homology, potential functions of the genes encoding MYB, HD-ZIP, and bZIP-HY5 transcription factors, as well as WD40 protein, which may be involved in anthocyanin and flavonoid regulation in these species. These candidate genes are associated with natural regulation in flower color in other plant species and will facilitate future studies aimed at elucidating the molecular basis of adaptive differentiation and the evolution of mechanisms of pollinator-mediated reproductive isolation in these two bromeliads. In addition, we identified a total of 49,439 microsatellite loci. These resources will assist future research into adaptation and speciation events in bromeliad species, thus providing a starting point for investigation of the molecular mechanisms of the traits responsible for their reproductive isolation.

本研究报道了两个具有不同主要传粉系统的杂交凤梨（bromeliad）物种的叶片与花转录组（transcriptome）。我们鉴定了这两个物种中参与传粉者吸引与生殖隔离的候选基因，并针对花色等花部性状相关的候选基因开展了筛选。从两个物种的两类组织中共获得约34 Gbp的cDNA序列数据，总计得到424,506,914条原始读段（raw reads）。从头组装的转录组共包含263,955个重叠群（contigs），进一步聚类得到110,977个单基因簇（unigenes）。超过58%的单基因簇获得了功能注释，并被归类至一个或多个基因本体（Gene Ontology, GO）条目。转录组分析共发现144个编码类黄酮与花青素生物合成通路关键酶的独特转录本（transcripts）。通过结构域/家族注释与系统发育分析，我们可基于同源性推断MYB、HD-ZIP、bZIP-HY5转录因子以及WD40蛋白编码基因的潜在功能，这类基因可能参与上述物种的花青素与类黄酮调控过程。上述候选基因在其他植物物种中与花色的自然调控机制相关，将为后续阐明这两个凤梨物种适应性分化的分子基础，以及传粉者介导的生殖隔离机制的演化过程提供助力。此外，我们共鉴定得到49,439个微卫星位点（microsatellite loci）。这些组学资源将为后续凤梨物种的适应性演化与物种形成研究提供支持，并为解析其生殖隔离相关性状的分子机制奠定研究基础。