Genome-wide identification of TCP gene family and functional analysis of PcTCP8 gene related to trichome development...

Trichomes are key sites for synthesis and storage of plant secondary metabolites. The TCP transcription factor family is essential for trichomes cell fate determination. In Pogostemon cablin, trichome density significantly affects the accumulation of terpenoid metabolites, but the role of TCP gene family in this process is unclear. This study characterized TCP proteins in P. cablin and explored the impact of PcTCP8 on trichome development and volatile compound biosynthesis. It identified 44 PcTCP proteins and used transcriptome data for expression profiling, providing functional insights. Over-expression of PcTCP8 decreased patchoulol content, virus-induced gene silencing (VIGS) of PcTCP8 resulted in increased trichome density, elevated patchoulol levels, and upregulated expression of PcFFPS. These findings demonstrate that PcTCP8 acts as a negative regulator of both glandular trichome development and essential oil biosynthesis in P. cablin. The study provides novel insights into the genetic regulation of glandular trichomes in medicinal plants, offering valuable information for future research in this field.