Jia Haotian, Geng Xiaoyun, Fan Lina, Li Xin, Wang Jiao, Hao Ruijie
College of Horticulture, Shanxi Agricultural University, Jinzhong 030600, China.
Plants (Basel). 2024 Mar 1;13(5):703. doi: 10.3390/plants13050703.
The species consists of uniquely aromatic woody perennials with large amounts of free aromatic substances in the flower cells. Uridine diphosphate glycosyltransferase (UGT) modifies these free aromatic substances into water-soluble glycoside-bound volatiles (GBVs) which play an important role in regulating the use of volatiles by plants for information exchange, defense, and stress tolerance. To investigate the changes in the glycosidic state of aromatic substances during the flowering period of and discern the location and expression of glycoside synthesis genes, we extracted and enzymatically hydrolyzed GBVs of and then utilized gas chromatography-mass spectrometry (GC-MS) to characterize and analyze the types and contents of GBV glycosides. Further, we identified and classified the members of the UGT gene family of using the bioinformatic method and analyzed the correlation between the expression of the UGT family genes in and the changes in glycosidic content. The results showed that the benzenoids were the main aromatic substance that was glycosylated during flowering in and that glycosidic benzaldehyde was the most prevalent compound in different flower parts and at different flowering stages. The titer of glycoside benzaldehyde gradually increased during the bud stage and reached the highest level at the big bud stage (999.6 μg·g). Significantly, titers of glycoside benzaldehyde significantly decreased and stabilized after flowering while the level of free benzaldehyde, in contrast, significantly increased and then reached a plateau after the flowering process was completed. A total of 155 UGT family genes were identified in the genome, which were divided into 13 subfamilies (A-E, G-N); according to the classification of UGT gene subfamilies, the L subfamily contains 17 genes. The transcriptome analysis showed that and were highly expressed in the bud stage and were strongly correlated with the content of the glycosidic form of benzaldehyde at all stages of flowering. This study provides a theoretical basis to elucidate the function of UGT family genes in during flower development, to explore the mechanism of the storage and transportation of aromatic compounds in flower tissues, and to exploit industrial applications of aromatic products from .
该物种由独特芳香的多年生木本植物组成，其花细胞中含有大量游离芳香物质。尿苷二磷酸糖基转移酶（UGT）将这些游离芳香物质转化为水溶性糖苷结合挥发物（GBV），GBV在调节植物利用挥发物进行信息交换、防御和胁迫耐受方面发挥着重要作用。为了研究该植物花期芳香物质糖苷化状态的变化，并识别糖苷合成基因的位置和表达情况，我们提取并酶解了该植物的GBV，然后利用气相色谱-质谱联用（GC-MS）对GBV糖苷的类型和含量进行表征和分析。此外，我们采用生物信息学方法对该植物UGT基因家族成员进行了鉴定和分类，并分析了该植物UGT家族基因的表达与糖苷含量变化之间的相关性。结果表明，苯丙烷类化合物是该植物花期糖苷化的主要芳香物质，糖苷化苯甲醛是不同花部和不同花期最普遍的化合物。糖苷化苯甲醛的含量在花蕾期逐渐增加，在大花蕾期达到最高水平（999.6 μg·g）。值得注意的是，开花后糖苷化苯甲醛的含量显著下降并趋于稳定，而游离苯甲醛的含量则相反，在开花过程完成后显著增加，然后达到平稳状态。在该植物基因组中总共鉴定出155个UGT家族基因，它们被分为13个亚家族（A-E、G-N）；根据该植物UGT基因亚家族的分类，L亚家族包含17个基因。转录组分析表明，该植物和在花蕾期高表达，并且在开花的各个阶段都与苯甲醛糖苷形式的含量密切相关。本研究为阐明UGT家族基因在该植物花发育过程中的功能提供了理论依据，有助于探索花组织中芳香化合物的储存和运输机制，并开发该植物芳香产品的工业应用。
