《植物生理学报》 2021, 57(3): 569-578

苗期乌拉尔甘草GuHMGR基因表达特性与甘草酸合成和
积累关系的研究

毕权¹，姚华¹，何大俊²，李国治¹，沈海涛^1,2,*

¹河子大学生命科学学院, 新疆石河子832000；²新疆植物药资源教育部重点实验室, 新疆石河子832000

通信作者：沈海涛；E-mail: 281128603@qq.com

摘　要：

甘草酸是药用甘草(Glycyrrhiza uralensis)最主要的活性成分之一, 其含量也是评价甘草品质的主要指标。通过分析苗期乌拉尔甘草不同部位的甘草酸含量及其合成途径中关键基因GuHMGR表达特性和结构信息, 了解其在甘草酸合成和积累作用。结果显示, 甘草酸主要在苗期乌拉尔甘草地下部分中积累, 而甘草酸合成前体甘草次酸并不会大量积累, 说明乌拉尔甘草中甘草次酸合成后迅速转化为甘草酸。GuHMGR启动子调控元件分析显示GuHMGR1、GuHMGR3、 GuHMGR4基因主要受逆境胁迫和光诱导
调控, 而GuHMGR2基因的启动子可能因缺少光响应调控元件导致其主要在地下部分表达。 GuHMGR基因家族中GuHMGR1在地下部分中的表达量显著高于其他三个基因, GuHMGR1基因可能是甘草酸地下部分中合成的主效基因; 而且, 不同的GuHMGR基因在地上和地下部分中表达量差异较大, 其蛋白结构、启动子的调控元件也并不相同, 故推测不同GuHMGR基因在乌拉尔甘草中承担不同的功能。

关键词：乌拉尔甘草; 甘草酸; GuHMGR; 启动子

收稿：2020-11-08   修定：2021-03-01

资助：国家自然科学基金(31460376)、兵团科技计划项目(2018AB012、 2020AA005)和石河子大学科研项目(ZZZC201931B)

Relationship between expression characteristics of GuHMGR gene and glycyrrhizic acid synthesis and accumulation in seedlings of Glycyrrhiza uralensis

BI Quan¹, YAO Hua¹, HE Dajun², LI Guozhi¹, SHEN Haitao^1,2,*

¹College of Life Sciences, Shihezi University, Shihezi, Xinjiang 832000, China; ²Key Laboratory of Xinjiang Phytomedicine Resource and Utilization of Ministry of Education, Shihezi, Xinjiang 832000, China

Corresponding author: SHEN Haitao; E-mail: 281128603@qq.com

Abstract:

Glycyrrhizic acid is one of the most important components of medicinal licorice, and its content
is also the main index to evaluate the quality of Glycyrrhiza uralensis. In this study, we analyzed the glycyrrhizic acid content in different parts of G. uralensis seedlings and the expression characteristics and structural information of GuHMGRs, in order to understand the role of GuHMGRs in glycyrrhizic acid biosynthesis and accumulation. The results showed that glycyrrhizic acid accumulated mainly in the underground part of G. uralensis seedlings. Its precursor, glycyrrhetinic acid, did not accumulate in large amount, indicating that it was rapidly converted into glycyrrhizic acid after synthesis. Analysis of GuHMGR promoter regulatory elements showed that GuHMGR1, GuHMGR3 and GuHMGR4 were mainly regulated by stress and light, while GuHMGR2 was mainly expressed in underground part due to the lack of light responsive regulatory elements within its promoter. The expression level of GuHMGR1 in the underground part is signifcantly higher than that of the other three genes of GuHMGR gene family. Therefore, GuHMGR1 could be the main gene responsible for the synthesis of glycyrrhizic acid in the underground part. Moreover, the expression levels of different GuHMGR genes in the aerial and underground parts were quite different, and their protein structure and promoter regulatory elements are also quite different. Therefore, it is speculated that different GuHMGR genes have different roles in G. uralensis.

Key words: Glycyrrhiza uralensis; glycyrrhizic acid; GuHMGR; promoter