Genome-Wide Analysis and Expression Profiles of AhLOG Gene Family in Peanut (Arachis hypogaea L.)

Peanut (Arachis hypogaea L.) is a globally vital oilseed and cash crop. The LONELY GUY (LOG) gene family acts as a core regulator of cytokinin activation, governing plant meristem maintenance, growth, development, and stress responses. However, the genome-wide characteristics, evolutionary dynamics, and biological functions remain largely uncharacterized in peanut. In this study, 24 AhLOG genes were identified from the cultivated peanut Tifrunner. Phylogenetic analysis, gene structure characterization, and conserved motifs validated the high evolutionary conservation of the AhLOG gene family, and subcellular localization prediction indicated most AhLOG proteins were distributed in the cytoplasm. Promoter cis-element analysis revealed abundant hormone-responsive and stress-responsive cis-elements in the promoter regions of the AhLOG genes. Synteny analysis uncovered highly conserved collinear relationships between cultivated peanut and its diploid progenitors (A. duranensis, A. ipaensis) as well as the wild tetraploid relative (A. monticola), while numerous conserved orthologous syntenic pairs were detected between peanut and the model plant Arabidopsis thaliana. Tissue expression profiles revealed remarkable functional divergence among members: AhLOG3 and AhLOG16 were widely involved in both vegetative and reproductive development, while several other AhLOG genes exhibited strict tissue-specific expression. Furthermore, qRT-PCR analysis demonstrated that AhLOG genes were significantly induced by abscisic acid (ABA), gibberellin (GA), indole-3-acetic acid (IAA), methyl jasmonate (MeJA), drought and salt treatments, with distinct expression patterns under these abiotic stress conditions. Collectively, this work provides a systematic understanding of the AhLOG gene family and offers key candidate genes along with theoretical support for further functional investigation and molecular breeding of stress-resistant peanut.