Genome-Wide Identification and Transcript Analysis Reveal Potential Roles of Oligopeptide Transporter Genes in Iron Deficiency Induced Cadmium Accumulation in Peanut.

The oligopeptide transporter (OPT) family is a group of proton-coupled symporters that play diverse roles, including metal homeostasis. However, little is known about this family of peanuts. To reveal the potential roles of genes in Fe/Cd interactions, peanut genes were genome-widely identified, and the relationships between gene expression and Cd accumulation were detected in two contrasting peanut cultivars (Fenghua 1 and Silihong) under Fe-sufficient or Fe-deficient conditions. A total of 40 genes were identified in peanuts, which were divided into two subfamilies (PT and YS). Most genes underwent gene duplication events predominated by whole-genome duplication. Clustered members generally have similar protein structures. However, gene structural divergences occurred in most of the duplicated genes. Transcription analysis revealed that / and / might be responsible for Fe deficiency tolerance, while //, and be involved in Fe/Cd interactions. These genes might be regulated by transcription factors, including , and . Reduced expressions of / and higher expressions of might contribute to higher Fe-deficiency tolerance in Silihong. Higher expression of and might be responsible for low Cd accumulation in Fenghua 1. Our results confirmed that // and / might be involved in the transport of Fe and/or Cd in peanuts and provided new clues to understanding potential mechanisms of Fe/Cd interactions.