Zinc finger protein 5 of Platanus × acerifolia promotes trichome initiation by targeting PaGL2 directly

Platanus × acerifolia is a widely used street tree. From spring to autumn, continuous leaf growth and development prolongs the shedding period of leaf trichomes, posing potential health risks due to airborne trichomes. However, research on leaf trichome development in P. × acerifolia remains scarce. In this study, we revealed that the transcription factor PaZFP5 is highly expressed in the high trichome density germplasm 'Huanong Lifeng', controlling the initiation and development of glandular and non-glandular trichomes by directly targeting PaGL2. Overexpression of PaZFP5 in Arabidopsis thaliana and tobacco increased the number of non-glandular and glandular trichomes and significantly elongated glandular trichomes. The Arabidopsis thaliana mutant zfp5 led to a significant reduction in the number of leaf trichomes, while overexpression of PaZFP5 in the zfp5 background significantly increased the number of leaf trichomes in Arabidopsis thaliana. In vitro and in vivo experiments showed that PaZFP5 can activate downstream PaGL2 expression, and there is a protein interaction between PaZFP5 and PaZFP8. This study elucidates the regulatory pathways involved in trichome development in P. × acerifolia, providing valuable genetic resources and theoretical foundations for the breeding of glabrous P. × acerifolia varieties.