基于表观遗传学的甘草酸高效合成“记忆”机制解析研究

How to improve the content of glycyrrhizic acid in cultivated licorice is a matter of concern in the field of traditional Chinese medicine resources. The results showed that the content of glycyrrhizic acid in the licorice produced by the rhizome breeding of the wild licorice was significantly higher than that produced by the seed breeding of the wild licorice ,under the genetic background and the cultivation conditions. In order to reveal its mechanism, combined with the growth environment of the wild licorice rhizomes, we present the "memory" hypothesis about the high efficient synthesis of glycyrrhizic acid. Based on the phenomenon of "memory" of licorice synthesis in field cultivation and artificial simulation of adversity stress, the key memory genes were determined by two aspects: field cultivation and artificial simulation, gene expression and product analysis.The apparent genetic mechanism of the "memory" hypothesis of glycyrrhizic acid was analyzed by methylation analysis of the promoter region and the transcriptional region of the key memory gene under different stress conditions, and methylation and acetylation of key memory genomic proteins ,so as to identify the memory factor of the key memory gene. The study aimed to provide the basis for regulating the synthesis efficiency of glycyrrhizic acid and improving the content of the glycyrrhizic acid in the cultivated licorice, and to provide reference for improving the quality of other cultivated medicinal materials.

如何提高栽培甘草甘草酸含量是当前中药资源领域备受关注的问题。前期研究表明在遗传背景及栽培条件栽相同时，野生甘草根状茎作为繁殖材料产生的药材的甘草酸含量显著高于种子作为繁殖材料产生的药材的甘草酸含量。为了揭示其机制，结合野生甘草根状茎的生长环境，我们提出了甘草酸高效合成“记忆”假说。本研究在大田栽培及人工模拟逆境胁迫证明甘草酸高效合成存在“记忆”现象的基础上，通过大田栽培及人工模拟两种条件，基因表达及产物分析两个方面，确定关键记忆基因；通过对关键记忆基因在不同逆境条件下启动子区域、转录区域的甲基化分析及关键记忆基因组蛋白的甲基化与乙酰化分析，解析甘草酸高效合成“记忆”假说的表观遗传机制，确定关键记忆基因的记忆因子。为调控栽培甘草甘草酸的合成效率，提高栽培甘草的甘草酸含量提供科学依据，并为其他栽培药材质量提高的研究提供借鉴意义。