PDF(Pubmed)
Abstract：
Zephyranthes candida is a frequently cultivated ornamental plant containing several secondary metabolites, including alkaloids, flavonoids, and volatile organic compounds (VOCs). However, extensive research has been conducted only on non-VOCs found in the plant, whereas the production of VOCs and the molecular mechanisms underlying the biosynthesis of terpenes remain poorly understood. In this study, 17 volatile compounds were identified from Z. candida flowers using gas chromatography-mass spectrometry (GC-MS), with 16 of them being terpenoids. Transcriptome sequencing resulted in the identification of 17 terpene synthase (TPS) genes; two TPS genes, ZcTPS01 and ZcTPS02, had high expression levels. Biochemical characterization of two enzymes encoded by both genes revealed that ZcTPS02 can catalyze geranyl diphosphate (GPP) into diverse products, among which is β-ocimene, which is the second most abundant compound found in Z. candida flowers. These results suggest that ZcTPS02 plays a vital role in β-ocimene biosynthesis, providing valuable insights into terpene biosynthesis pathways in Z. candida. Furthermore, the expression of ZcTPS02 was upregulated after 2 h of methyl jasmonate (MeJA) treatment and downregulated after 4 h of the same treatment.
摘要：
假丝酵母是一种经常栽培的观赏植物，含有几种次生代谢产物，包括生物碱,黄酮类化合物，和挥发性有机化合物(VOCs)。然而,仅对工厂中发现的非挥发性有机化合物进行了广泛的研究，而挥发性有机化合物的产生和萜烯生物合成的分子机制仍然知之甚少。在这项研究中,使用气相色谱-质谱（GC-MS）从Z.念珠菌花中鉴定出17种挥发性化合物。其中16种是萜类化合物。转录组测序结果鉴定了17个萜烯合酶（TPS）基因；两个TPS基因，ZcTPS01和ZcTPS02具有高表达水平。两个基因编码的两种酶的生化特征表明，ZcTPS02可以催化香叶基二磷酸（3GPP）成不同的产物，其中有β-新烯,这是Z.念珠菌花中发现的第二丰富的化合物。这些结果表明，ZcTPS02在β-辛烯生物合成中起着至关重要的作用，为Z.念珠菌中萜烯生物合成途径提供有价值的见解。此外，茉莉酸甲酯（MeJA）处理2小时后，ZcTPS02的表达上调，而相同处理4小时后，ZcTPS02的表达下调。
