Identification of Key Genes in the Synthesis Pathway of Volatile Terpenoids in Fruit of <i>Zanthoxylum bungeanum</i> Maxim

• Main Authors: Jingwei Shi, Xitong Fei, Yang Hu, Yulin Liu, Anzhi Wei
• Format: Article
• Language: English
• Published: MDPI AG 2019-04-01
• Series: Forests
• Subjects: <i>Zanthoxylum bungeanum</i> Maxim.; aroma; terpenoid; bioinformatics analysis; developmental stages
• Online Access: https://www.mdpi.com/1999-4907/10/4/328

<i>Zanthoxylum bungeanum</i> Maxim. (<i>Z. bungeanum</i>), a plant that belongs to the Rutaceae family, is widely planted in China. Its outstanding feature is its rich aroma. The main component that creates this aroma is the volatile terpenoids. In this study, we aimed to understand the molecular mechanism related to aroma synthesis in <i>Z. bungeanum</i> and provide new ideas for breeding. Headspace solid phase micro extraction-gas chromatography mass spectrometry (HS-SPME-GC-MS), RT-qPCR and bioinformatics were used to study the changes in volatile terpenoids and identify key genes in the pathway of terpenoids in fruits of <i>Z. bungeanum</i>. The results show that the trend of volatile terpenoids is consistent among the two varieties. As the fruit matures, the terpenoids gradually accumulate and peak in the third period (mid-development) before gradually decreasing. Among these terpenoids, there is the highest content of &#945;-pinene. In <i>Z. bungeanum</i> cv. &#8216;Hanchengdahongpao&#8217; (Hanchengdahongpao) and <i>Z. bungeanum</i> cv. &#8216;Fuguhuajiao&#8217; (Fuguhuajiao), this reached 24.74% and 20.78% respectively. In general, for the content of volatile terpenoids, Hanchengdahongpao is 62% and Fuguhuajiao is 41%. The results of RT-qPCR showed that most gene expression in this study was upregulated. Among them, <i>ZbDXS</i> has the highest relative level of expression in itself, which is the key rate-limiting enzymein the MEP pathway. These results explore the synthetic route of terpenoids during the ripening process of <i>Z. bungeanum</i>, which provides a reference for cultivar and improving good traits.