Sidorenko L, Li X, Tagliani L, Bowen B, Peterson T
Department of Zoology and Genetics, Iowa State University, Ames 50011, USA.
Plant Mol Biol. 1999 Jan;39(1):11-9. doi: 10.1023/a:1006172815663.
The maize P-rr gene conditions floral-specific flavonoid pigmentation, especially in the kernel pericarp and cob. We analyzed the P-rr promoter by transient expression assays, in which segments of the P-rr promoter were fused to the GUS reporter gene and introduced into maize cells by particle bombardment. A basal P-rr promoter fragment (-235 to +326) gave low, but significant, levels of GUS reporter gene expression. Interestingly, two widely spaced segments containing enhancer-like activity were found. When tested individually, both the proximal (-1252 to -236) and distal (-6110 to -4842) segments boosted expression of the basal P-rr promoter::GUS construct about five-fold. A 1.6 kb segment of the P-rr promoter (-1252 to +326) containing the proximal enhancer and the 5'-untranslated leader driving the GUS reporter gene showed preferential expression in BMS and embryogenic suspension cell cultures vs. endosperm-derived suspension cell cultures. These results demonstrate the application of transient assay techniques for the identification of regulatory elements responsible for floral-specific regulation of the complex P-rr gene promoter in maize.
玉米P-rr基因决定花特异性黄酮类色素沉着，特别是在籽粒果皮和穗轴中。我们通过瞬时表达分析对P-rr启动子进行了分析，即将P-rr启动子片段与GUS报告基因融合，并通过粒子轰击导入玉米细胞。一个基础P-rr启动子片段（-235至+326）产生了低水平但显著的GUS报告基因表达。有趣的是，发现了两个间隔较远但具有增强子样活性的片段。单独测试时，近端片段（-1252至-236）和远端片段（-6110至-4842）都使基础P-rr启动子::GUS构建体的表达提高了约五倍。包含近端增强子和驱动GUS报告基因的5'非翻译前导序列的1.6 kb P-rr启动子片段（-1252至+326）在BMS和胚性悬浮细胞培养物中相对于胚乳来源的悬浮细胞培养物表现出优先表达。这些结果证明了瞬时分析技术在鉴定负责玉米复杂P-rr基因启动子花特异性调控的调控元件方面的应用。
