中药是国际竞争优势产业，中药材作为根本之源，需求与日俱增，但其重金属超标严重制约国际化进程，I类致癌物Cd是其面临最主要风险因素。申请人提出以典型Cd富集大宗药材黄连为研究对象，揭示核心转运体NRAMP特性及功能，阐释Cd富集分子机制，解决无公害精准种植科学问题。本项目将重点研究：①利用基因组深度测序技术，结合纳米孔测序及染色体图谱构建技术，获得黄连全基因组精细图谱；挖掘金属转运体家族基因，阐述结构特性与Cd富集相关性。②深度解析Cd胁迫黄连转录谱，揭示其基因调控网络协同表达规律；构建酵母表达及毛状根转化体系，探究NRAMP亚细胞定位及Cd吸收转运能力，阐释Cd富集分子机制。③外源施加必需元素并揭示黄连Cd吸收调控关系，探索低Cd精准种植技术体系；识别黄连自然群体NRAMP基因多态性，建立指征黄连低Cd品种分子标记。本研究将为中药材重金属富集机制研究提供借鉴，为无公害精准种植提供科学依据。

Medicinal herbs are the material basis of traditional Chinese medicine, one of the internationally competitive industries in China. In recent years, the demand of the herbs is soaring, while their internationalization process was severely constrained for serious problems, such as heavy metals in excess of standards, and Cd, IARC Type I carcinogen, is the most important risk factor. In order to resolve the scientific problem of pollution-free precision plant, we intent to take the typical Cd enriched herb Coptis chinensis as research material to elucidate its enrichment mechanism based on characteristics and functions investigating of the NRAMP family genes. Three aspects following will be studied in this project: 1) Firstly, assembling the whole detailed genome map of C. chinensis at chromosome level from the data sequenced using Illumina, PacBio and Nanopore platform, and the chromosome conformation information obtained using Hi-C technology. mining the metal transporter family genes and describing the correlation between their structural characteristics and the Cd enrichment of C. chinensis. 2) Then, the transcription spectra of exogenous Cd treated C. chinensis roots were analyzed to reveal the regulatory rule of the gene synergistic expression network about the Cd enrichment. The subcellular localization and Cd transport capacity of NRAMPs are revealed based on the constructed yeast expression and hairy root transformation systems, the Cd enrichment molecular mechanism was then elucidated based on the NRAMPs functions. 3) Finally, revealing the regulatory relationship of Cd absorption in C. chinensis by exogenous application of essential elements, and then to explore its low Cd precise planting technology system. The NRAMP gene polymorphisms are identified in natural populations to establish variety screening molecular markers for low Cd C. chinensis. The results of this research can provide a technical support and theoretical basis for the heavy metal enrichment mechanism on Chinese medicinal materials, and for the precise pollution-free planting of medicinal herbs.