背景:大冶3号是苜蓿(MedicagosativaL.)的新品种,由于其高产和显着的抗寒性,非常适合在青藏高原等高海拔地区种植。然而,转录组信息的有限可用性阻碍了我们对该品种耐冷性潜在机制的研究。因此,我们进行了从头转录组组装以克服这一限制。随后,我们比较了大冶号的基因表达模式。3在不同时间点的冷适应和暴露于冷胁迫期间。
结果:共有15个苜蓿样品包含在转录组组装中,产生141.97Gb的清洁底座。冷驯化共诱导441个DEGs,在12小时时识别出4525、5016和8056个DEG,24h,在4°C下长时间冷应激后36小时,分别。RT-qPCR和转录组数据之间的一致性证实了转录组数据的准确性和可靠性。KEGG富集分析表明,许多与光合作用相关的基因在冷胁迫下被富集。STEM分析表明,在冷胁迫下,参与氮代谢和TCA循环的基因始终上调。而与光合作用相关的基因,特别是触角蛋白基因,被下调。PPI网络分析显示,泛素化相关的核糖体蛋白在响应冷应激时充当枢纽基因。此外,植物激素信号通路在寒冷胁迫下被激活,表明其在苜蓿冷应激反应中的重要作用。
结论:冷适应诱导的泛素化相关核糖体蛋白在早期冷信号转导中起关键作用。作为枢纽基因,这些泛素化相关的核糖体蛋白调节许多下游基因以响应冷应激。与氮代谢和TCA循环相关的基因的上调以及植物激素信号通路的激活有助于紫花苜蓿的耐寒性增强。
BACKGROUND: Daye No.3 is a novel cultivar of alfalfa (Medicago sativa L.) that is well suited for cultivation in high-altitude regions such as the Qinghai‒Tibet Plateau owing to its high yield and notable cold resistance. However, the limited availability of transcriptomic information has hindered our investigation into the potential mechanisms of cold tolerance in this cultivar. Consequently, we conducted de novo transcriptome assembly to overcome this limitation. Subsequently, we compared the patterns of gene expression in Daye No. 3 during cold
acclimatization and exposure to cold stress at various time points.
RESULTS: A total of 15 alfalfa samples were included in the transcriptome assembly, resulting in 141.97 Gb of clean bases. A total of 441 DEGs were induced by cold acclimation, while 4525, 5016, and 8056 DEGs were identified at 12 h, 24 h, and 36 h after prolonged cold stress at 4 °C, respectively. The consistency between the RT‒qPCR and transcriptome data confirmed the accuracy and reliability of the transcriptomic data. KEGG enrichment analysis revealed that many genes related to photosynthesis were enriched under cold stress. STEM analysis demonstrated that genes involved in nitrogen metabolism and the TCA cycle were consistently upregulated under cold stress, while genes associated with photosynthesis, particularly antenna protein genes, were downregulated. PPI network analysis revealed that ubiquitination-related ribosomal proteins act as hub genes in response to cold stress. Additionally, the plant hormone signaling pathway was activated under cold stress, suggesting its vital role in the cold stress response of alfalfa.
CONCLUSIONS: Ubiquitination-related ribosomal proteins induced by cold acclimation play a crucial role in early cold signal transduction. As hub genes, these ubiquitination-related ribosomal proteins regulate a multitude of downstream genes in response to cold stress. The upregulation of genes related to nitrogen metabolism and the TCA cycle and the activation of the plant hormone signaling pathway contribute to the enhanced cold tolerance of alfalfa.