OsGL6, a conserved AP2 domain protein, promotes leaf trichome initiation in rice

Trichomes are specialized epidermal cells that play crucial roles in resisting environmental stress and enhancing plant development. In Arabidopsis thaliana, the main genes controlling trichome formation have been consecutively identified. However, few genes like this were reported in rice. In this study, we identified the hairy phenotype of indica variety 75-1-127. This was used to construct a segregation population with a cross of hairless variety Minghui63 (MH63) to fine map the trichome formation genes. Genetic analysis indicated that hairy phenotype was controlled by a pair of dominant genes on chromosome 6, which was designated as GLABRA6 (OsGL6). OsGL6 was an allele of HL6 gene whose sequences containing rich variations in genomes. Compared to wild type, the overexpressing transgenic lines revealed that OsGL6 promoted trichome initiation. We found that OsGL6 interacted with serine/threonine protein kinase OSK3 (OSK3) or COP9 signalosome complex subunit 5a (CSN5) in yeast. These results provide potential information for understanding the molecular mechanism of trichome formation in rice.