Abstract
The CONSTANS-like (COL) gene family plays critical roles in plant growth, development, stress responses, and light signal transduction. However, its functions in peanut (Arachis hypogaea) remain poorly understood. In this study, we identified 18 AhCOL genes in the peanut genome, all localized in the nucleus. Phylogenetic analysis classified these genes into three subfamilies, with Group I containing eight members and Groups II and III each comprising five. Conserved domain analysis revealed that all AhCOL proteins possess at least one B-box and one CCT domain. Most of the AhCOL members in peanuts contain a large number of ABA and MeJA elements. Additionally, some members have low-temperature response elements, anaerobic induction, circadian control, and defense stress elements. Expression profiling indicated that most AhCOL genes are abundantly expressed in leaves, flowers, and fruit needles. Notably, genes such as AhCOL4, AhCOL8, AhCOL13, and AhCOL14 were upregulated under light induction and mechanical stress, highlighting their involvement in pod development. AhCOL1 interacts with AhNF-YC1, while AhCOL3 interacts with both AhNF-YC1 and AhCOP1 proteins. This study identifies key AhCOL genes implicated in light and mechanical stress responses, offering insights into their potential roles in peanut flowering and abiotic stress tolerance.