Genome-Wide Identification and Characterization of NRAMP family members in <i>Miscanthus sinensis</i>

Miscanthus is extensively cultivated as a pioneer plant, demonstrates excellent performance in coping with heavy metal stress. However, existing research on Miscanthus and its mechanisms for heavy metal transport is limited, particularly regarding the genetic mechanisms underlying of its tolerance to heavy metals. This study aimed to fill the knowledge gap concerning the role of NRAMP (natural resistance associated macrophage protein) genes in Miscanthus, as NRAMP has been widely reported to facilitate the transport of heavy metal ions in other plants. A total of seventeen MsNRAMP genes were identifed in Miscanthus sinensis, which can be classified into two major groups and are characterized by a high degree of conservation in their secondary structure, the presence of ion-binding sites characteristic of the Leu-T domain, and an average of 9-12 transmembrane domains. Our findings significantly enhance the understanding of metal ion balance and stress response mechanisms in Miscanthus sinensis. Specifically, we discovered that only MsNRAMP3 and MsNRAMP7 are expressed under normal conditions, while the remaining MsNRAMP genes exhibit low or no expression. Additionally, MsNRAMP14 and MsNRAMP8 were found to have numerous ABA and MeJA response elements in their promoter regions, suggesting a potential role in stress response.