Genome-Wide Identification and Characterization of the Phytochrome Gene Family in Peanut.

To investigate the potential role of phytochrome (PHY) in peanut growth and its response to environmental fluctuations, eight candidate genes were identified via genome-wide analysis of cultivated peanut. These AhPHY polypeptides were determined to possess acidic and hydrophilic physiochemical properties and exhibit subcellular localization patterns consistent with residence in the nucleus and cytoplasm. Phylogenetic analysis revealed that the gene family members were classified into three subgroups homologous to the progenitors of . genes within the same clade largely displayed analogous gene structure, conserved motifs, and phosphorylation sites. exhibited symmetrical distribution across peanut chromosomes, with 7 intraspecific syntenic gene pairs in peanut, as well as 4 and 20 interspecific syntenic gene pairs in and soybean, respectively. A total of 42 -elements were predicted in promoters, including elements implicated in phytohormone regulation, stress induction, physiology, and photoresponse, suggesting putative fundamental roles across diverse biological processes. Moreover, spatiotemporal transcript profiling of genes in various peanut tissues revealed distinct expression patterns for each member, alluding to putative functional specialization. This study contributes novel insights into the classification, structure, molecular evolution, and expression profiles of the peanut phytochrome gene family, and also provides phototransduction gene resources for further mechanistic characterization.