Molecular Dissection of TaLTP1 Promoter Reveals Functional Cis-Elements Regulating Epidermis-Specific Expression

oleh: Guiping Wang, Guanghui Yu, Yongchao Hao, Xinxin Cheng, Jinxiao Zhao, Silong Sun, Hongwei Wang

Format: Article
Diterbitkan: MDPI AG 2020-03-01

Deskripsi

Plant epidermis serves important functions in shoot growth, plant defense and lipid metabolism, though mechanisms of related transcriptional regulation are largely unknown. Here, we identified <i>cis-</i>elements specific to shoot epidermis expression by dissecting the promoter of Triticum<i> </i>aestivum lipid transfer protein 1 (<i>TaLTP1</i>). A preliminary promoter deletion analysis revealed that a truncated fragment within 400 bp upstream from the translation start site was sufficient to confer conserved epidermis-specific expression in transgenic <i>Brachypodium distachyon</i> and <i>Arabidopsis thaliana</i>. Further, deletion or mutation of a GC(N4)GGCC motif at position &#8722;380 bp caused a loss of expression in pavement cells. With an electrophoretic mobility shift assay (EMSA) and transgenic reporter assay, we found that a light-responsive CcATC motif at position &#8722;268 bp was also involved in regulating pavement cell-specific expression that is evolutionary conserved. Moreover, expression specific to leaf trichome cells was found to be independently regulated by a CCaacAt motif at position -303 bp.