State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Tai'an 271018, China.
Int J Mol Sci. 2020 Mar 25;21(7):2261. doi: 10.3390/ijms21072261.
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 elements specific to shoot epidermis expression by dissecting the promoter of Triticum aestivum lipid transfer protein 1 (). 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 and . Further, deletion or mutation of a GC(N4)GGCC motif at position -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 -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.
植物表皮在芽生长、植物防御和脂质代谢中具有重要功能，但相关转录调控的机制在很大程度上尚不清楚。在这里，我们通过剖析小麦脂质转移蛋白 1 () 的启动子，鉴定出了芽表皮表达特异性元件。初步的启动子缺失分析表明，翻译起始位点上游 400bp 内的截断片段足以在转基因 和 中赋予保守的表皮特异性表达。此外，在位置-380bp 处缺失或突变 GC（N4）GGCC 基序会导致 pavement 细胞表达丧失。通过电泳迁移率变动分析 (EMSA) 和转基因报告基因分析，我们发现位置-268bp 的光响应 CcATC 基序也参与调节进化保守的 pavement 细胞特异性表达。此外，位置-303bp 的 CCaacAt 基序被发现可独立调节叶片毛状体细胞的表达特异性。
