江汉大学学报（自然科学版）

为探究氮肥对不同氮敏感型小麦抗倒伏能力形成以及转录组差异基因表达的影响，以氮敏感型小麦YM19和氮不敏感型小麦NM9两个小麦品种为材料，设置施纯氮180 kg/hm²(N1)、240 kg/hm²(N2)两个氮素水平，对开花后7 d小麦茎秆倒二节间进行RNA-seq转录组测序，结合KOG、GO和KEGG数据库进行差异表达基因的功能注释与通路分析。结果表明，氮敏感型品种YM19在N2与N1处理下的差异表达基因数量(2 444个)显著多于对氮不敏感型品种NM9(470个)，表明两个品种对氮水平变化的响应存在显著的品种特异性，YM19对氮素更敏感。功能注释与通路分析显示，YM19的差异表达基因涉及17个KOG功能类别，在生物过程、细胞组分、分子功能三大GO分类维度均有大量差异基因富集，且能注释到细胞过程、环境信息处理等4大类共9个KEGG通路，涵盖基因表达调控、碳水化合物运输与代谢、信号转导、能量代谢等关键过程；而NM9的差异表达基因仅涉及4个KOG功能类别，GO分类中差异基因数量远少于YM19，且未注释到任何KEGG通路。研究证实，品种间差异表达基因的数量、功能类别及参与的代谢通路不同，是导致其抗倒性能对氮水平响应存在特异性的核心分子机制，这些差异基因通过调控小麦茎秆的物质代谢、细胞结构和信号转导等过程，参与抗倒性能的形成与维持。本研究为小麦抗倒伏品种的分子育种及田间氮肥精准施用提供了理论依据。

To explore the effects of nitrogen fertilizer on the formation of lodging resistance and the expression of transcriptomic differentially expressed genes(DEGs) in wheat varieties with different nitrogen sensitivities,two wheat varieties,nitrogen-sensitive YM19 and nitrogen-insensitive NM9, were used as experimental materials. Two nitrogen application levels were set,namely 180 kg/hm²(N1) and 240 kg/hm²(N2) of pure nitrogen. RNA-seq transcriptome sequencing was performed on the second internode from the top of wheat stems at 7 days after flowering. Functional annotation and pathway analysis of DEGs were conducted using KOG,GO,and KEGG databases. The results showed that the number of DEGs in the nitrogen-sensitive variety YM19 under N2 compared with N1(2 444)was significantly higher than that in the nitrogen-insensitive variety NM9(470),indicating a significant varietal specificity in the response of the two varieties to changes in nitrogen levels,with YM19 being more sensitive to nitrogen. Functional annotation and pathway analysis revealed that the DEGs of YM19 were involved in 17 KOG functional categories,with a large number of DEGs enriched in the three GO classification dimensions(biological process,cellular component,and molecular function),and could be annotated to nine KEGG pathways belonging to four major categories(cellular processes,environmental information processing,etc.),covering key processes such as gene expression regulation,carbohydrate transport and metabolism,signal transduction,and energy metabolism. In contrast,the DEGs of NM9 were only involved in only four KOG functional categories,the number of DEGs in GO classifications was much lower than that in YM19,and no KEGG pathways were annotated. This study confirmed that differences in the number,functional categories, and involved metabolic pathways of DEGs between varieties are the core molecular mechanisms underlying the specific response of lodging resistance to nitrogen levels. These DEGs participate in the formation and maintenance of lodging resistance by regulating processes such as substance metabolism,cell structure,and signal transduction in wheat stems. This study provides a theoretical basis for the molecular breeding of lodgingresistant wheat varieties and the precise application of nitrogen fertilizer in the field.