Genome-Wide Analysis of Peanut DOG1 Family Identifies AhDOG1-2 as a Genetic Target for Improving Seed Dormancy and...

Seed dormancy is a vital adaptive trait that ensures germination occurs under favorable environmental conditions, significantly affecting crop yield and quality. However, the genetic regulation of dormancy remains poorly understood in peanut, limiting efforts to improve preharvest sprouting (PHS) resistance. In this study, we carried-out a genome-wide analysis of the DELAY OF GERMINATION 1 (DOG1)-domain-containing gene family in peanut and identified 35 members, comprising 12 DOG1-like and 23 TGA-related genes. Phylogenetic and structural analyses revealed clade-specific divergence, with AhDOG1-2 showing strong seed-preferential expression and responsiveness to abscisic acid (ABA). Subcellular localization assays showed that AhDOG1-2 localizes to both the nucleus and cytoplasm, and yeast transactivation assays confirmed its transcriptional activity. Functional validation showed that AhDOG1-2 overexpression in Arabidopsis enhances seed dormancy and increases ABA sensitivity. Furthermore, transgenic rice expressing AhDOG1-2 exhibited reduced PHS without significant agronomic penalties. Expression analysis revealed that these phenotypic changes were accompanied by reprogramming of genes involved in ABA and gibberellin (GA) pathways. These findings identify AhDOG1-2 as a conserved dormancy regulator with cross-species potential, providing the first functional characterization of DOG1 homologs in peanut and highlighting AhDOG1-2 as a promising molecular target for genetic improvement of dormancy and PHS resistance in crops.