State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China.
Int J Mol Sci. 2018 Mar 12;19(3):822. doi: 10.3390/ijms19030822.
ZmbZIP25 ( bZIP (basic leucine zipper) transcription factor 25) is a function-unknown protein that belongs to the D group of the bZIP transcription factor family. RNA-seq data showed that the expression of was tissue-specific in maize silks, and this specificity was confirmed by RT-PCR (reverse transcription-polymerase chain reaction). In situ RNA hybridization showed that was expressed exclusively in the xylem of maize silks. A 5' RACE (rapid amplification of cDNA ends) assay identified an adenine residue as the transcription start site of the gene. To characterize this silk-specific promoter, we isolated and analyzed a 2450 bp (from -2083 to +367) and a 2600 bp sequence of (from -2083 to +517, the transcription start site was denoted +1). Stable expression assays in showed that the expression of the reporter gene driven by the 2450 bp 5'-flanking fragment occurred exclusively in the papillae of stigmas. Furthermore, transient expression assays in maize indicated that and expression driven by the 2450 bp 5'-flanking sequences occurred only in maize silks and not in other tissues. However, no or expression was driven by the 2600 bp 5'-flanking sequences in either stable or transient expression assays. A series of deletion analyses of the 2450 bp 5'-flanking sequence was performed in transgenic plants, and probable elements prediction analysis revealed the possible presence of negative regulatory elements within the 161 bp region from -1117 to -957 that were responsible for the specificity of the 5'-flanking sequence.
Zm bZIP25（bZIP（碱性亮氨酸拉链）转录因子 25）是一种功能未知的蛋白质，属于 bZIP 转录因子家族的 D 组。RNA-seq 数据显示，在玉米花丝中， 的表达具有组织特异性，这一特异性通过 RT-PCR（逆转录-聚合酶链反应）得到了证实。原位 RNA 杂交显示， 在玉米花丝的木质部中特异性表达。5'RACE（cDNA 末端快速扩增）实验确定了腺嘌呤残基是 基因的转录起始位点。为了表征这种丝特异启动子，我们分离并分析了一个 2450bp（-2083 到+367）和一个 2600bp 序列的 （-2083 到+517，转录起始位点记为+1）。在 中稳定表达实验表明，由 2450bp 5'侧翼片段驱动的报告基因 的表达仅发生在柱头的乳突中。此外，在玉米中的瞬时表达实验表明，由 2450bp 5'侧翼序列驱动的 和 表达仅发生在玉米花丝中，而不在其他组织中发生。然而，在稳定或瞬时表达实验中，由 2600bp 5'侧翼序列驱动的 或 表达都没有发生。对 2450bp 5'侧翼序列进行了一系列缺失分析，在转基因 植物中进行了实验，可能的元件预测分析表明，在-1117 到-957 的 161bp 区域内可能存在负调控元件，这些元件负责 5'侧翼序列的特异性。
