Identification and characterization of PaGL1-like genes from Platanus acerifolia related to the regulation of trichomes.

Abstract

Two PaGL1-like genes were identified in London plane and functional in Arabidopsis, moreover, may play an important role in the regulation of trichome development in London plane. Trichome development is governed by a complex regulatory network. In Arabidopsis, subgroup 15 of the R2R3 MYB transcription factor family, which includes GLABRA1 (GL1), is involved in trichome development. In this study, we isolated and characterized two PaGL1-like genes from London plane (Platanus acerifolia). Sequence alignment and phylogenetic analysis indicated that these PaGL1-like genes are homologous to AtGL1. Quantitative real-time PCR (qRT-PCR) analysis showed that PaGL1-like1 was expressed in all of the tested organs taken from adult London plane trees, including trichomes, petioles after trichome removal, stems after trichome removal, and leaves after trichome removal, and also in the roots, cotyledons, hypocotyls and true leaves of seedlings. By contrast, the PaGL1-like2 was expressed only in the trichomes and leaves after trichome removal from adult trees, and in the cotyledons and true leaves of seedlings. Overexpression of PaGL1-like genes caused trichome abortion when transferred into wild type Arabidopsis and promoted trichome formation in the gl1 mutant. The expression profiles of some trichome-related genes were changed in transgenic Arabidopsis lines, and yeast two-hybrid analysis indicated that PaGL1-like proteins can directly interact with trichome-related bHLH proteins from both P. acerifolia and Arabidopsis. These results suggest that PaGL1-like genes are functional in Arabidopsis and may play an important role in the regulation of trichome development in London plane.