Dissecting the roles of EgHd3a genes in flower induction and development of oil palm (Elaeis guineensis).

The regulation of flowering is crucial for optimizing palm oil yield and ensuring adaptation to environmental conditions. This study investigates two FLOWERING LOCUS T (FT) homologs in oil palm (Elaeis guineensis), EgHd3a-1 and EgHd3a-2, to elucidate their roles in flowering induction and developmental processes. Quantitative PCR and GUS reporter assays in Arabidopsis thaliana revealed that EgHd3a-1 is predominantly expressed in reproductive tissues and vascular structures, functioning analogously to FT as a floral inducer. In contrast, EgHd3a-2 displayed broader expressions across both vegetative and reproductive tissues, particularly during early growth stages, suggesting a role in organ development rather than direct floral induction. Overexpression of EgHd3a-1 and EgHd3a-2 in A. thaliana resulted in distinct flowering phenotypes, with EgHd3a-1 mutants exhibiting accelerated flowering under long-day conditions. Promoter analysis of pEgHd3a-1 and pEgHd3a-2 identified unique cis-acting regulatory elements associated with tissue specificity and environmental responsiveness, reinforcing their complementary functions. These findings provide a molecular basis for targeted genetic modification of flowering time in oil palm, offering significant potential for accelerating breeding cycles, improving yields optimization, and enhancing resilience to environmental changes.