PaMYB82 from Platanus acerifolia regulates trichome development in transgenic Arabidopsis

The control of epidermal cell fate is an elaborate molecular process mediated by the TTG1-bHLH-MYB regulatory complex. In this study, we isolated PaMYB82 from London plane. PaMYB82 was revealed to be a nuclear-localized transcription activator and was found to be expressed ubiquitously in the tissues of roots, stems, leaves, cotyledons and hypocotyls. Expression of the PaMYB82 gene under the control of the viral CaMV35S promoter caused a nearly glabrous phenotype in wild type Arabidopsis and can partially rescue the gl1 mutant phenotype. Protein interaction analysis revealed that PaMYB82 physically interacts with PaGL3 and itself, in addition, PaMYB82 could interact with trichome related bHLH transcription factors AtGL3, AtEGL3 and AtMYC1. Expression levels of AtGL2, AtTTG2 and several R3 MYB genes were greatly increased in 35S::PaMYB82 lines. The expression of AtMYB23 was reduced in 35S::PaMYB82 transgenic lines, whereas, expression levels of AtGL1 remained unchanged indicating that differences in the transcriptional regulation of AtMYB23 and AtGL1 during trichome development. Together, the data presented here indicate that PaMYB82 encodes a functional R2R3 MYB transcription factor which can control the initiation of Arabidopsis trichome development.