Plant Biotechnology Laboratory, Centre of Excellence in Molecular Biology (CEMB), University of the Punjab, Lahore 53700, Pakistan.
Viruses. 2014 Jan 14;6(1):223-42. doi: 10.3390/v6010223.
The C1 promoter expressing the AC1 gene, and V1 promoter expressing the AV1 gene are located in opposite orientations in the large intergenic region of the Cotton leaf curl Burewala virus (CLCuBuV) genome. Agro-infiltration was used to transiently express putative promoter constructs in Nicotiana tabacum and Gossypium hirsutum leaves, which was monitored by a GUS reporter gene, and revealed that the bidirectional promoter of CLCuBuV transcriptionally regulates both the AC1 and AV1 genes. The CLCuBuV C1 gene promoter showed a strong, consistent transient expression of the reporter gene (GUS) in N. tabacum and G. hirsutum leaves and exhibited GUS activity two- to three-fold higher than the CaMV 35S promoter. The CLCuBuV bidirectional gene promoter is a nearly constitutive promoter that contains basic conserved elements. Many cis-regulatory elements (CREs) were also analyzed within the bidirectional plant promoters of CLCuBuV and closely related geminiviruses, which may be helpful in understanding the transcriptional regulation of both the virus and host plant.
C1 启动子表达 AC1 基因，V1 启动子表达 AV1 基因，位于棉花曲叶病毒（CLCuBuV）基因组大基因间区的相反方向。农杆菌浸润法用于瞬时表达拟南芥和棉花叶片中的推定启动子构建体，通过 GUS 报告基因进行监测，结果表明 CLCuBuV 的双向启动子转录调控 AC1 和 AV1 基因。CLCuBuV 的 C1 基因启动子在烟草和棉花叶片中强烈、一致地瞬时表达报告基因（GUS），并表现出比 CaMV 35S 启动子高 2-3 倍的 GUS 活性。CLCuBuV 的双向基因启动子是一个近乎组成型的启动子，包含基本的保守元件。还分析了 CLCuBuV 和密切相关的双生病毒的双向植物启动子内的许多顺式调控元件（CREs），这可能有助于理解病毒和宿主植物的转录调控。
