Abstract: To explore the molecular mechanisms and metabolic pathways of genes related to the symbiotic relationship between ‘Mengnong Clover No.1’ (T. ambiguum Bieb. ‘Mengnong No.1’) and rhizobia,this study selected ‘Mengnong Clover No.1’ inoculated with rhizobia and an uninoculated control group as research subjects. Through transcriptomic sequencing,we compared the transcriptome differences between symbiotic and non-symbiotic states. The results showed that,compared with the uninoculated group,a total of 1105 differentially expressed genes (DEGs) were identified with significant changes of expression levels in all symbiotic samples. Among them,677 genes were upregulated and 428 genes were downregulated. The reliability of the transcriptomic sequencing was confirmed by real-time quantitative PCR (qRT-PCR) for some of these genes. Further analysis revealed that these DEGs were involved in multiple metabolic pathways and biological processes,including biosynthesis of phenylpropanoids,metabolism of amino sugars and nucleotide sugars,as well as cysteine and methionine metabolism. This study reveals the transcriptomic characteristics of ‘Mengnong Clover No.1’ under symbiotic conditions with rhizobia,and provides important references for a deeper understanding of the symbiotic mechanisms between plants and rhizobia.

Key words: ‘Mengnong Clover No. 1’, Rhizobium inoculation, Differentially expressed genes (DEGs), Transcriptomics

摘要： 为探究‘蒙农三叶草1号’(Trifolium ambiguum Bieb. ‘Mengnong No.1’)与根瘤菌共生过程中相关基因的分子机制及代谢通路，本研究选取了接种根瘤菌的‘蒙农三叶草1号’以及未接种的对照组为研究对象，通过转录组测序，比较了共生与非共生状态下的转录组差异。结果表明，与未接种组相比，接种组共筛选出1105个差异表达基因(Differentially expressed genes，DEGs)。进一步分析发现，这些DEGs涉及多个代谢通路和生物学过程，包括苯丙烷生物合成、氨基糖和核苷酸糖代谢、半胱氨酸和甲硫氨酸代谢等。其中，677个基因上调，428个基因下调。通过实时荧光定量PCR(qRT-PCR)对部分基因进行验证，证实了转录组测序的可靠性。本研究揭示了‘蒙农三叶草1号’在根瘤菌共生状态下的转录组特征，为深入理解植物与根瘤菌共生机制提供了重要参考。

关键词: ‘蒙农三叶草1号’, 接种根瘤菌, 差异表达基因, 转录组学