Biotechnology Bulletin ›› 2024, Vol. 40 ›› Issue (5): 191-202.doi: 10.13560/j.cnki.biotech.bull.1985.2023-1161

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Identification and Expression Analysis of the NRAMP Family in Seabuckthorn Under Lead Stress

LI Jia-xin(), LI Hong-yan, LIU Li-e, ZHANG Tian, ZHOU Wu()   

  1. College of Eco-Environmental Engineering, Qinghai University, Xining 810016
  • Received:2023-12-10 Online:2024-05-26 Published:2024-06-13
  • Contact: ZHOU Wu E-mail:2544313591@qq.com;zhouwu870624@163.com

Abstract:

Objective】The NRAMP(natural resistance-associated macrophage protein)gene family plays a pivotal role in the transport of divalent metal ions at the cellular level. To identify the key NRAMP family genes in seabuckthorn (Hippophae rhamnoides) that confer resistance to heavy metal lead stress and to elucidate the associated molecular mechanisms.【Method】Using bioinformatics techniques, we identified seabuckthorn's NRAMP gene family members and comprehensively analyzed their physicochemical properties, phylogenetic relationships, gene structures, conserved motifs, cis-acting elements, expression profiles under varying Pb stress concentrations, intraspecific and interspecific variability, and protein interaction networks. 【Result】The 11 NRAMP gene family members were distributed across seven chromosomes and categorized into Groups 1-Group 3. Promoters of the NRAMP genes contained numerous hormonal, meristematic, and environmental stress response elements. Transcriptome analysis indicated differential expressions of NRAMP genes in seabuckthorn under varying lead ion concentrations, with eight genes significantly down-regulated at 1 000 mg/kg and seven up-regulated at 5 000 mg/kg lead levels. RT-qPCR validated the expression patterns of six chosen NRAMP genes in seabuckthorn. The seabuckthorn NRAMP genes showed greater interspecific co-linkage with monocotyledonous wheat than with the dicot Arabidopsis thaliana. Protein network analysis suggested that HrLNRAMP8 potentially regulates heavy metal uptake and translocation primarily via the ethylene pathway. 【Conclusion】A systematic identification of 11 HrLNRAMP family members from seabuckthorn was achieved at the whole-genome level. Members of the Group2 subfamily have the most complex gene structures and lower consistency. All seabuckthorn NRAMP members contain the unique transport domain motif1 of the NRAMP family. The study demonstrates preferential expression of different gene family members under lead stress conditions. This gene family regulates gene expression levels in response to heavy metal lead ion stress, thereby mitigating damage caused by heavy metal stress.

Key words: seabuckthorn(Hippophae rhamnoides), NRAMP gene family, bioinformatics analysis, heavy metal stress, expression analysis