Lei Yuyang, Harris A J, Wang Aihua, Zhao Liyun, Luo Ming, Li Ji, Chen Hongfeng
Key Laboratory of Plant Resources Conservation and Sustainable Utilization South China Botanical Garden Chinese Academy of Sciences Guangzhou China.
Wuhan Guishan Mountain Scenic Management Office Wuhan China.
Ecol Evol. 2022 May 19;12(5):e8920. doi: 10.1002/ece3.8920. eCollection 2022 May.
(Primulaceae) is highly valued in traditional medicine due to its production of the pharmacologically active secondary metabolites, especially triterpenoid saponins in its roots. Although . is very important in traditional medicine, the genetic basis for its production of triterpenoid saponins remains largely unknown. Therefore, we sequenced transcriptomes of . to identify putative genes involved in production of triterpenoid saponins in both leaves and roots, and we used the transcriptomes to compare expression levels of these genes between the two organ systems. The production of triterpenoid saponins in plants is usually induced through hormonal signaling on account of the presence of pests. Thus, we treated plants with the hormones salicylic acid (SA) and methyl jasmonate (MeJA) and used quantitative real-time PCR (qRT-PCR) to investigate expression levels of genes involved in triterpenoid saponin biosynthesis. In total, we obtained transcriptomes for leaf and root tissues representing 52,454 unigenes. Compared with the leaf transcriptome, we found that 6092 unigenes were upregulated in the root, especially enzymes involved in the direct synthesis of triterpenoid saponins, while 6001 genes appeared downregulated, including those involved in precursory steps in the triterpenoid saponin biosynthesis pathway. Our results from qRT-PCR indicate that genes within the upstream parts of the triterpenoid saponin biosynthesis pathway may be upregulated under exposure to the applied hormones, but downstream genes are downregulated. This suggests possible conflicting effects of SA and MeJA in promoting the production of secondary metabolites on the one hand, and, on the other, limiting plant growth processes to devote energy to combating pests. We also performed an analysis of transcription factors (TFs) and found 997 unique transcripts belonging to 16 TF families. Our data may help to facilitate future work on triterpene saponins biosynthesis in . with potential pharmacological and molecular breeding applications.
报春花科植物因其根中产生具有药理活性的次生代谢产物，尤其是三萜皂苷，而在传统医学中具有很高的价值。尽管报春花科植物在传统医学中非常重要，但其产生三萜皂苷的遗传基础仍 largely 未知。因此，我们对报春花科植物的转录组进行了测序，以鉴定参与叶片和根中三萜皂苷产生的假定基因，并利用转录组比较这两个器官系统中这些基因的表达水平。由于害虫的存在，植物中三萜皂苷的产生通常通过激素信号诱导。因此，我们用激素水杨酸（SA）和茉莉酸甲酯（MeJA）处理植物，并使用定量实时 PCR（qRT-PCR）来研究参与三萜皂苷生物合成的基因的表达水平。我们总共获得了代表 52454 个单基因的叶和根组织的转录组。与叶转录组相比，我们发现根中有 6092 个单基因上调，特别是参与三萜皂苷直接合成的酶，而 6001 个基因下调，包括那些参与三萜皂苷生物合成途径前期步骤的基因。我们的 qRT-PCR 结果表明，三萜皂苷生物合成途径上游部分的基因在暴露于所施加的激素时可能上调，但下游基因下调。这表明 SA 和 MeJA 一方面在促进次生代谢产物产生方面可能存在相互矛盾的影响，另一方面在限制植物生长过程以投入能量对抗害虫方面也可能存在相互矛盾的影响。我们还对转录因子（TFs）进行了分析，发现了属于 16 个 TF 家族的 997 个独特转录本。我们的数据可能有助于促进未来对报春花科植物三萜皂苷生物合成的研究，具有潜在的药理学和分子育种应用。
