Orchardgrass (Dactylis glomerata L.) is an economically important perennial forage grass with a high biomass, abundant carbohydrates, shade tolerance, and broad adaptability. The time of flowering is a crucial agronomic trait that is strongly relevant to the quality and yield of orchardgrass. However, there has been little information provided about the genes expressed during the critical flower development stages. In this study, we performed a comparative transcriptome analysis at different stages in which we compared the early- and late-flowering phenotypes of orchardgrass to identify the regulators and pathways that are involved in timing of flowering. Based on our results, 2561 and 3885 differentially expressed genes (DEGs) were identified between the late- and early-flowering phenotypes of orchardgrass in vernalization stage (VE) and before heading (BH) stages, respectively. Gene ontology analysis indicated that the DEGs in VE stage were primarily related to plant hormones, development processes, and environmental stimulation in response to vernalization induction. At the BH stage, DEGs were related to plant development processes and organ formation and differentiation. A large number of heat shock factors (HSFs) were detected in cooperation with plant hormone regulators in the heading (HT) stage. Ultimately, 50 flowering genes discovered were studied as DEGs between different phenotypes in flowering time, and 25 of those flowering DEGs were involved in the photoperiod pathway. These 50 DEGs revealed gene transcripts that corresponded to flowering-associated differences, and they provide novel insights into the molecular mechanisms that underlie regulation of flowering in early-flowering and late-flowering phenotypes of orchardgrass.

中文翻译：

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比较转录分析表明牧草 Dactylis glomerata L 早花和晚花表型的不同开花反应

果园草（Dactylis glomerata L.）是一种经济上重要的多年生牧草，具有高生物量、丰富的碳水化合物、耐荫性和广泛的适应性。开花时间是一个关键的农艺性状，与果园的质量和产量密切相关。然而，关于在关键的花发育阶段表达的基因的信息很少。在这项研究中，我们在不同阶段进行了转录组比较分析，比较了果园草的早花和晚花表型，以确定与开花时间相关的调节因子和途径。根据我们的结果，分别在春化阶段（VE）和抽穗前（BH）阶段的果园晚花和早花表型之间鉴定了2561和3885个差异表达基因（DEG）。基因本体分析表明，VE阶段的DEGs主要与植物激素、发育过程和响应春化诱导的环境刺激有关。在 BH 阶段，DEGs 与植物发育过程和器官形成和分化有关。在抽穗（HT）阶段与植物激素调节剂协同检测到大量热休克因子（HSFs）。最终，发现的50个开花基因作为开花时间不同表型之间的DEGs进行了研究，其中25个开花DEGs参与了光周期途径。