The AP2/ERF transcription factor (TF) family is of great importance in developmental regulation and responses to stress and pathogenic stimuli. Orchardgrass (Dactylis glomerata), a perennial cold-season forage of high quality in the world’s temperate zones, contributes to grazing land through mixed sowing with alfalfa (Medicago sativa) and white clover (Trifolium repens). However, little is known about AP2/ERF TFs in orchardgrass. In this study, 193 AP2/ERF genes were classified into five subfamilies and 13 subgroups through phylogenetic analysis. Chromosome structure analysis showed that AP2/ERF family genes in orchardgrass were distributed on seven chromosomes and specific conservative sequences were found in each subgroup. Exon–intron structure and motifs in the same subgroup were almost identical, and the unique motifs contributed to the classification and functional annotation of DgERFs. Expression analysis showed tissue-specific expression of DgERFs in roots and flowers, with most DgERFs widely expressed in roots. The expression levels of each subgroup (subgroups Vc, VIIa, VIIIb, IXa, and XIa) were high at the before-heading and heading stages (BH_DON and H_DON). In addition, 12 DgERFs in various tissues and five DgERFs associated with abiotic stresses were selected for qRT-PCR analysis showed that four dehydration-responsive element binding (DREB) genes and one ERF subfamily gene in orchardgrass were regulated with PEG, heat and salt stresses. DgERF056 belonged to ERF subfamily was involved in the processes of flowering and development stage. This study systematic explored the DgERFs at the genome level for the first time, which lays a foundation for a better understanding of AP2/ERF gene function in Dactylis glomerata and other types of forage.

AP2 / ERF转录因子（TF）家族在发育调节以及对压力和病原刺激的反应中非常重要。Orchardgrass（Dactylis glomerata）是世界温带地区多年生冷季优质牧草，通过与紫花苜蓿（苜蓿）和白三叶草（Trifolium repens）混合播种，有助于放牧土地）。但是，人们对果园中的AP2 / ERF TF知之甚少。在这项研究中，通过系统进化分析，将193个AP2 / ERF基因分为5个亚家族和13个亚组。染色体结构分析表明，果园中的AP2 / ERF家族基因分布在七个染色体上，并且在每个亚组中都发现了特定的保守序列。外显子-内含子的结构和基序在同一亚组中几乎相同，并且独特的基序有助于DgERF的分类和功能注释。表达分析表明，DgERF在根和花中具有组织特异性表达，其中大多数DgERF在根中广泛表达。在抽穗前和抽穗前阶段（BH_DON和H_DON），每个亚组（Vc，VIIa，VIIIb，IXa和XIa子组）的表达水平较高。此外，选择了12种DgERF和5种与非生物胁迫相关的DgERF进行qRT-PCR分析，结果表明，PEG，热和热调节了果园中的四个脱水反应元件结合（DREB）基因和一个ERF亚家族基因。盐胁迫。属于ERF亚科的DgERF056参与了开花和发育阶段的过程。本研究首次在基因组水平上对DgERF进行了系统的探索，为进一步了解AP2 / ERF基因功能奠定了基础。Dactylis glomerata和其他类型的草料。