January 13, 2025 | BMC Plant Biology |
Researchers from South China Agricultural University, China, conducted a study to investigate the role of gibberellin-3 (GA3) in regulating flower bud development in pitaya (Hylocereus polyrhizus). While flowering is known to be a complex process involving multiple phytohormones and transcription factors, limited information is available on the regulation of flowering in pitaya. This study aimed to address this gap by examining the effects of GA3 application on flower bud formation.
The results showed that GA3 treatment during the peak flowering period induced bud dormancy and suppressed flower bud formation. Hormone analysis revealed that GA3 application reduced the levels of auxin (AUX), active cytokinins such as dihydrozeatin riboside (dhZR), zeatin riboside (ZR), N6-isopentenyladenosine (iPA), and brassinosteroids (BR). In contrast, levels of jasmonic acid (JA), GA3, and gibberellin-4 (GA4) increased, while abscisic acid (ABA) remained unchanged. Flower bud formation was associated with higher levels of AUX, cytokinins, ABA, and JA, along with reduced GA3 and GA4 levels.
Transcriptomic analysis identified differentially expressed genes related to phytohormone signaling pathways. GA3 treatment inhibited genes involved in floral development, including those from the ABC model and floral identity genes such as LFY and FT. The findings suggest GA3 plays a key role in regulating flowering and promoting bud dormancy in pitaya.
