Zhang Mei, Hu Jixun, Hu Tao, Li Chunjie
State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosytems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China.
BMC Genomics. 2025 Sep 24;26(1):808. doi: 10.1186/s12864-025-11912-3.
Perennial ryegrass (Lolium perenne L.) is a widely cultivated turfgrass and forage species. AP2/ERF transcription factors play indispensable roles in plant growth and development, particularly in responses to biotic and abiotic stresses. However, comprehensive knowledge of this family in perennial ryegrass remains underexplored.
In this study, a total of 172 LpAP2/ERF genes were identified in the perennial ryegrass genome and renamed according to their chromosomal distribution. Phylogenetic and synteny analyses were performed using rice to investigate the evolution of the AP2/ERF genes in perennial ryegrass. These 172 LpAP2/ERF genes were categorized into four distinct subfamilies: the AP2 subfamily (25), the ERF subfamily (84), the DREB subfamily (59), and the RAV subfamily (4). Within each subfamily, gene structure and motif compositions were conserved. The analysis of cis-acting elements in LpAP2/ERF gene promoters suggests that these genes may play crucial roles in plant growth, development, and stress responses. Analysis of the expression patterns of AP2/ERF family genes in endophyte-infected perennial ryegrass under low nitrogen induction showed that a total of 44 LpAP2/ERF genes had significantly different expression levels. 39 genes responded strongly to nitrogen starvation in both endophyte-infected and endophyte-free perennial ryegrass, while 21 genes were expressed in response to infection by endophytic fungi under normal and low nitrogen conditions. Importantly, through GO, KEGG enrichment pathway analysis and protein interaction network prediction, two key core genes (LpAP2/ERF64 and LpAP2/ERF164) were finally identified, which play an important role in enhancing perennial ryegrass's response to nitrogen starvation by endophytic fungi.
This study is the first to identify the characteristics of the AP2/ERF family in perennial ryegrass, providing invaluable information for further evolutionary and functional studies of AP2/ERF. It also contributes to a better understanding of the molecular basis of development and stress tolerance in this species and others.
多年生黑麦草（Lolium perenne L.）是一种广泛种植的草坪草和饲料作物。AP2/ERF转录因子在植物生长发育中发挥着不可或缺的作用，尤其是在应对生物和非生物胁迫方面。然而，多年生黑麦草中该家族的全面知识仍未得到充分探索。
在本研究中，在多年生黑麦草基因组中总共鉴定出172个LpAP2/ERF基因，并根据它们的染色体分布重新命名。使用水稻进行了系统发育和共线性分析，以研究多年生黑麦草中AP2/ERF基因的进化。这172个LpAP2/ERF基因被分为四个不同的亚家族：AP2亚家族（25个）、ERF亚家族（84个）、DREB亚家族（59个）和RAV亚家族（4个）。在每个亚家族中，基因结构和基序组成是保守的。对LpAP2/ERF基因启动子中的顺式作用元件分析表明，这些基因可能在植物生长、发育和胁迫反应中发挥关键作用。对低氮诱导下内生真菌感染的多年生黑麦草中AP2/ERF家族基因表达模式的分析表明，共有44个LpAP2/ERF基因的表达水平存在显著差异。39个基因在内生真菌感染和未感染的多年生黑麦草中对氮饥饿均有强烈反应，而21个基因在正常和低氮条件下对内生真菌感染有表达响应。重要的是，通过GO、KEGG富集途径分析和蛋白质相互作用网络预测，最终鉴定出两个关键核心基因（LpAP2/ERF64和LpAP2/ERF164），它们在增强多年生黑麦草对内生真菌引起的氮饥饿反应中起重要作用。
本研究首次鉴定了多年生黑麦草中AP2/ERF家族的特征，为AP2/ERF的进一步进化和功能研究提供了宝贵信息。它也有助于更好地理解该物种及其他物种发育和胁迫耐受性的分子基础。
