Isolation and expression of terminal flower1 (TFL1) gene in clove (Syzygium aromaticum L.)

Syzygium aromaticum L. is a tropical tree valued for aromatic buds that occur at the branch tips directly affecting yield. The molecular mechanisms of flowering regulation in clove, especially as the role of the TERMINAL FLOWER 1 (TFL1) gene, are poorly understood. Most research has emphasized morphology and environmental factors cues, leaving a significant gap in knowledge for improving productivity through breeding. This study aimed to isolate and characterize the S. aromaticum TFL1 (SaTFL1) gene and analyze its expression across different developmental stages. DNA and RNA were extracted from first young leaves of both vegetative (VG) and generative (GG) phase plants, successfully amplifying and sequencing the gene. Gene expression using Reverse Transcriptase PCR on cDNAs derived from both tissue types through comprehensive analysis, including BLAST and phylogenetic studies. Our results revealed that the deduced amino acid sequence of the partial SaTFL1 has high identity (86.70% to 98.11%) and similarity (96.22% to 100%) with TFL1/CEN2 proteins from 15 other plant species. SaTFL1 expression was only found in vegetative tissues but not in generative tissues. The absence of SaTFL1 expression in generative tissues suggests its key role in promoting vegetative growth and regulating phase transitions. This study is the first to isolate and analyze TFL1 expression in clove, highlighting its potential function in flowering regulation and improving clove productivity.