Genome-Wide Identification of the Ferric Chelate Reductase () Gene Family in Peanut and Its Diploid Progenitors: Structure, Evolution, and Expression Profiles.

The ferric chelate reductase () family plays a vital role in metal ion homeostasis in a variety of locations in the plants. However, little is known about this family in peanut (). This study aimed to identify genes from the genomes of peanut and the two diploid progenitors ( and ) and to analyze their gene/protein structures and evolution. In addition, transcriptional responses of genes to Fe deficiency and/or Cu exposure were investigated in two peanut cultivars with different Fe deficiency tolerance (Silihong and Fenghua 1). A total of nine, four, and three genes were identified in peanut, , and , respectively, which were divided into three groups. Most genes underwent WGD/segmental duplication, leading to the expansion of the gene family. In general, clustered members share similar gene/protein structures. However, significant divergences occurred in genes. Three out of five genes were lowly expressed in all tissues under normal conditions, which may be beneficial for avoiding gene loss. Transcription analysis revealed that and genes might be involved in the reduction of Fe/Cu in plasma membranes and plastids, respectively. genes appear to confer Fe reduction in the mitochondria. Moreover, Fe deficiency induced an increase of Cu accumulation in peanut plants in which and might be involved. Our findings provided new clues for further understanding the roles of genes in the Fe/Cu interaction in peanut.