Background

Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao is a traditional medicinal herb of Leguminosae since it contains bioactive compounds such as flavonoids, which have significant pharmacological effects on immunity and antioxidant. However, the scanty genomic and transcriptome resources of Astragalus membranaceus have hindered further exploration of its biosynthesis and accumulation mechanism.

Objective

This project aim to further improve our understanding of the relationship between transcriptional behavior and flavonoids content of A. mongholicus.

Methods

The accumulation of flavonoids and related gene expression in five different developmental stages (A: vegetative, B: florescence, C: fruiting, D: fruit ripening and E: defoliating stages) of A. mongholicus root were studied by combining UV spectrophotometry and transcriptomic techniques. The de novo assembly, annotation and functional evaluation of the contigs were performed with bioinformatics tools.

Results

After screening and assembling the raw data, there were a total of 158,123 unigenes with an average length of 644.89 bp were finally obtained, which has 8362 unigenes could be jointly annotated by NR, SwissProt, eggNOG, GO, KEGG and Pfam databases. KEGG enrichment analysis was performed on differentially expressed genes(DEGs)in the four groups (A vs. B, B vs. C, C vs. D, D vs. E). The results showed that many DEGs in each group were significantly enriched to flavonoids biosynthesis related pathways. Among them, a number of 86 were involved in the biosynthesis of isoflavonoid (12), flavonoid (5) and phenylpropanoid (69). Further analysis of these DEGs revealed that the expression levels of key genes such as PAL, 4CL, CCR, COMT, DFR, etc. were all down-regulated at the fruiting stage, and then raised at the fruit ripening stage. This expression pattern was similar to the accumulation trend of total flavonoids content.

Conclusions

In summary, this comprehensive transcriptome dataset allowed the identification of genes associated with flavonoids metabolic pathways. The results laid a foundation for the biosynthesis and regulation of flavonoids. It also provided a scientific basis for the most suitable harvest time and resource utilization of A. mongholicus.

中文翻译：

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黄芪变种的转录组测序和鉴定。蒙古根揭示了参与类黄酮生物合成的关键基因。

背景

黄芪（Fisch。）Bge。变种 Mongholicus（Bge。）Hsiao是豆科的传统药用植物，因为它含有生物活性化合物，例如黄酮类化合物，对免疫力和抗氧化剂具有重要的药理作用。然而，黄芪的基因组和转录组资源贫乏阻碍了其生物合成和积累机制的进一步探索。

目的

该项目旨在进一步增进我们对蒙古沙枣转录行为与黄酮含量之间关系的理解。

方法

结合紫外分光光度法和转录组学技术研究了黄gh根在五个不同发育阶段（A：营养，B：开花，C：出果，D：果实成熟和E：脱叶）的黄酮积累及相关基因表达。。该从头重叠群的组装，注释和功能评估，用生物信息学工具进行。

结果

经过筛选和汇总原始数据，最终获得了158,123个单基因，平均长度为644.89 bp，其中NR，SwissProt，eggNOG，GO，KEGG和Pfam数据库可以共同注释8362个单基因。对四个组中的差异表达基因（DEG）进行了KEGG富集分析（A对B，B对C，C对D，D对E）。结果表明，每组中的许多DEG均明显富集了类黄酮的生物合成相关途径。其中，有86个参与了异黄酮（12），黄酮（5）和苯丙烷（69）的生物合成。对这些DEGs的进一步分析显示，关键基因如PAL，4CL，CCR，COMT，DFR等在结果期都下调，然后在果实成熟期提高。这种表达模式类似于总黄酮含量的积累趋势。

结论

总而言之，这个全面的转录组数据集允许鉴定与类黄酮代谢途径相关的基因。该结果为黄酮类化合物的生物合成和调控奠定了基础。这也为蒙古蘑菇最适的收获时间和资源利用提供了科学依据。