Liu Jiawei, Hao Xinyan, Guo Yue, Wang Mingjiu, Huang Fan
Institute of Plant Protection, Inner Mongolia Academy of Agricultural and Animal Husbandry Sciences, Hohhot, China.
Institute of Grassland Research, Chinese Academy of Agricultural Science, Hohhot, China.
Front Genet. 2025 Jul 24;16:1600377. doi: 10.3389/fgene.2025.1600377. eCollection 2025.
Caucasian clover ( Bieb.), a perennial legume forage grass, exhibits strong adaptability and resistance to adverse conditions. Owing to its rhizome specificity, it cannot nodulate or fix nitrogen outside of its original location, which limits its promotion and cultivation. The phenomenon of spontaneous nodulation of Caucasian clover was observed for the first time in Inner Mongolia, and investigation of its nodulation and nitrogen fixation mechanisms assists in the subsequent promotion of Caucasian clover cultivation from a theoretical perspective.
In this study, rhizobia extracted from Caucasian clover were inoculated into the field, and the nodulation part of the root system was investigated during the regreening stage of the second year using transcriptomics and proteomics techniques.
The study identified 70,280 differentially expressed genes (DEGs) and 770 differentially expressed proteins (DEPs) in total, among which carbonic anhydrase, cyanate lyase, phenylalanine, caffeate/5-hydroxyferulate 3-O-methyltransferase, caffeoyl CoA 3-O methyltransferase, chalcone synthase, and chalcone isomerase may have been the main factors affecting the nodulation and nitrogen fixation of Caucasian clover. This study theoretically contributes to the future genetic validation and selection of Caucasian clover varieties with a strong ability to nodulate and fix nitrogen.
白三叶草（Trifolium repens L.）是一种多年生豆科牧草，具有较强的适应性和抗逆性。由于其根瘤的特异性，它在原生地以外无法结瘤固氮，这限制了其推广种植。在内蒙古首次观察到白三叶草自发结瘤现象，对其结瘤和固氮机制的研究有助于从理论层面推动白三叶草种植的后续推广。
本研究将从白三叶草中提取的根瘤菌接种到田间，在第二年返青期利用转录组学和蛋白质组学技术研究根系结瘤部位。
该研究共鉴定出70280个差异表达基因（DEGs）和770个差异表达蛋白（DEPs），其中碳酸酐酶、氰酸裂解酶、苯丙氨酸、咖啡酸/5-羟基阿魏酸3-O-甲基转移酶、咖啡酰辅酶A 3-O甲基转移酶、查尔酮合酶和查尔酮异构酶可能是影响白三叶草结瘤和固氮的主要因素。本研究在理论上有助于未来对白三叶草结瘤固氮能力强的品种进行遗传验证和选育。
