Chloroplastic pyruvate phosphate dikinase (PPDK) (chlPPDK) is a key enzyme in the photosynthesis of C4 plants. PPDK is expressed in high abundance in C4 plants but only in trace amounts in C3 plants. The existing research reveals a higher expression of MechlPPDK in cultivated cassava varieties than that in wild cassava W14. However, knowledge about the transcriptional regulation of the MechlPPDK gene in cassava (Manihot esculenta Crantz) is insufficient. Therefore, we aim to identify the transcription profile of MechlPPDK and the core promoter region of MechlPPDK. We cloned the MechlPPDK coding sequence and its 5′-flanking sequence from the cassava variety Ku50. A series of deletion constructions fused to a uidA reporter gene were performed in the 5′-flanking sequence and stably transformed into tobacco. We found that P1 (from −590 bp to +114 bp) had the highest promoter activity among P1 to P3. The 5′-flanking sequence of MechlPPDK responded differently to varied abiotic stresses. Our results will further the understanding of the regulation of MechlPPDK expression.

中文翻译：

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MechlPPDK启动子在转基因烟草中的分子功能表征

叶绿体丙酮酸磷酸二激酶（chDKPPDK）是C4植物光合作用的关键酶。PPDK在C4植物中高丰度表达，但在C3植物中仅微量表达。现有研究表明，MechlPPDK在木薯栽培品种中的表达高于野生木薯W14。然而，关于木薯中的MechlPPDK基因的转录调控的知识是不够的（Manihot esculenta Crantz）。因此，我们的目标是确定的转录概况MechlPPDK和核心启动子区MechlPPDK。我们克隆了MechlPPDK木薯品种Ku50的编码序列及其5'侧翼序列。在5'侧翼序列中进行了与uidA报告基因融合的一系列缺失构建，并稳定地转化为烟草。我们发现，P1（从-590 bp到+114 bp）在P1到P3中具有最高的启动子活性。MechlPPDK的5'侧翼序列对各种非生物胁迫的反应不同。我们的结果将进一步了解MechlPPDK表达的调控。