The number of plant species with genomic and transcriptomic data has been increasing rapidly. The grasses—Poaceae—have been well represented among species with published reference genomes. However, as a result the genomes of wild grasses are less frequently targeted by sequencing efforts. Sequence data from wild relatives of crop species in the grasses can aid the study of domestication, gene discovery for breeding and crop improvement, and improve our understanding of the evolution of C₄ photosynthesis. Here, we used long‐read sequencing technology to characterize the transcriptomes of three C₃ panicoid grass species: Dichanthelium oligosanthes, Chasmanthium laxum, and Hymenachne amplexicaulis. Based on alignments to the sorghum genome, we estimate that assembled consensus transcripts from each species capture between 54.2% and 65.7% of the conserved syntenic gene space in grasses. Genes co‐opted into C₄ were also well represented in this dataset, despite concerns that because these genes might play roles unrelated to photosynthesis in the target species, they would be expressed at low levels and missed by transcript‐based sequencing. A combined analysis using syntenic orthologous genes from grasses with published reference genomes and consensus long‐read sequences from these wild species was consistent with previously published phylogenies. It is hoped that these data, targeting underrepresented classes of species within the PACMAD grasses—wild species and species utilizing C₃ photosynthesis—will aid in future studies of domestication and C₄ evolution by decreasing the evolutionary distance between C₄ and C₃ species within this clade, enabling more accurate comparisons associated with evolution of the C₄ pathway.

中文翻译：

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C3 Panicoid草的IsoSeq转录组组装提供了研究Panicoideae中进化变化的工具。

具有基因组和转录组数据的植物种类的数量正在迅速增加。禾本科中的禾本科植物已经很好地代表了已发表参考基因组的物种。但是，结果是野生草的基因组很少被测序工作所靶向。来自草类作物野生近缘种的序列数据可以帮助驯化研究，基因育种和作物改良的研究，并有助于我们了解C ₄光合作用的演变。在这里，我们使用了长测序技术来表征三种C ₃圆锥花科草的转录组：低碳双歧杆菌（Dichanthelium oligosanthes），赤霞木（Chasmanthium laxum）和菊苣（Hymenachne amplexicaulis）。基于与高粱基因组的比对，我们估计每个物种的组装共有转录本在草丛中捕获的保守同位基因空间占54.2％至65.7％。尽管担心由于这些基因可能在目标物种中发挥与光合作用无关的作用，所以被选入C _4的基因在该数据集中也能很好地表示，因此它们会以低水平表达，并被基于转录的测序所错过。使用来自草的同系直系同源基因与已发布的参考基因组以及来自这些野生物种的共有的长读序列进行的组合分析与先前已发表的系统发育一致。希望这些数据针对PACMAD草中代表性不足的物种类别-野生物种和利用C _3的物种光合作用-通过减小此进化枝中C ₄和C ₃物种之间的进化距离，有助于与C ₄途径进化相关的更准确比较，从而有助于对驯化和C ₄进化的未来研究。