Identification of HMA gene family and response to cadmium stress in <i>Ophiopogon japonicas</i>.

Zhihui WANG; Erli NIU; Yuanliang GAO; Qian ZHU; Zihong YE; Xiaoping YU; Qian ZHAO; Jun HUANG

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Identification of HMA gene family and response to cadmium stress in Ophiopogon japonicas.

Author: Zhihui WANG ¹ ; Erli NIU ² ; Yuanliang GAO ¹ ; Qian ZHU ¹ ; Zihong YE ³ ; Xiaoping YU ³ ; Qian ZHAO ¹ ; Jun HUANG ¹
Author Information

1. School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou 310023, Zhejiang, China.
2. Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, Zhejiang, China.
3. College of Life Sciences, China Jiliang University, Hangzhou 310018, Zhejiang, China.
Publication Type:Journal Article
Keywords: HMA family; Ophiopogon japonicas; cadmium (Cd) stress; enrichment factor (EF); molecular docking
MeSH: Cadmium/metabolism*; Adenosine Triphosphatases/metabolism*; Ophiopogon/drug effects*; Soil Pollutants/toxicity*; Plant Proteins/metabolism*; Stress, Physiological; Multigene Family; Gene Expression Regulation, Plant
From: Chinese Journal of Biotechnology 2025;41(2):771-790
CountryChina
Language:Chinese
Abstract: Soil cadmium (Cd) pollution is one of the major environmental problems globally. Ophiopogon japonicus, a multifunctional plant extensively used in traditional Chinese medicine, has demonstrated potential in environmental remediation. This study investigated the Cd accumulation pattern of O. japonicus under cadmium stress and identified the heavy metal ATPase (HMA) family members in this plant. Our results demonstrated that O. japonicus exhibited a Cd enrichment factor (EF) of 2.75, demonstrating strong potential for soil Cd pollution remediation. Nine heavy metal ATPase (HMA) members of P1B-ATPases were successfully identified from the transcriptome data of O. japonicus, with OjHMA1-OjHMA6 classified as the Zn/Co/Cd/Pb-ATPases and OjHMA7-OjHMA9 as the Cu/Ag-ATPases. The expression levels of OjHMA1, OjHMA2, OjHMA3, and OjHMA7 were significantly up-regulated under Cd stress, highlighting their crucial roles in cadmium ion absorption and transport. The topological analysis revealed that these proteins possessed characteristic transmembrane (TM) segments of the family, along with functional A, P, and N domains involved in regulating ion absorption and release. Metal ion-binding sites (M4, M5, and M6) existed on the TM segments. Based on the number of transmembrane domains and the residues at metal ion-binding sites, the plant HMA family members were categorized into three subgroups: P1B-1 ATPases, P1B-2 ATPases, and P1B-4 ATPases. Specifically, the P1B-1 ATPase subgroup included the motifs TM4(CPC), TM5(YN[X]₄P), and TM6(M[XX]SS); the P1B-2 ATPase subgroup featured the motifs TM4(CPC), TM5(K), and TM6(DKTGT); the P1B-4 ATPase subgroup contained the motifs TM4(SPC) and TM6(HE[X]GT), all of which were critical for protein functions. Molecular docking results revealed the importance of conserved sequences such as CPC/SPC, DKTGT, and HE[X]GT in metal ion coordination and stabilization. These findings provide potential molecular targets for enhancing Cd uptake and tolerance of O. japonicus by genetic engineering and lay a theoretical foundation for developing new cultivars with high Cd accumulation capacity.