Verdaguer B, de Kochko A, Beachy R N, Fauquet C
International Laboratory for Tropical Agricultural Biotechnology (ILTAB/ORSTOM-TSRI), Scripps Research Institute, La Jolla, CA 92037, USA.
Plant Mol Biol. 1996 Sep;31(6):1129-39. doi: 10.1007/BF00040830.
The cassava vein mosaic virus (CVMV) is a double stranded DNA virus which infects cassava plants (Manihot esculenta Crantz) and has been characterized as a plant pararetrovirus belonging to the caulimovirus subgroup. Two DNA fragments, CVP1 of 388 nucleotides from position -368 to +20 and CVP2 of 511 nucleotides from position -443 to +72, were isolated from the viral genome and fused to the uidA reporter gene to test promoter expression. The transcription start site of the viral promoter was determined using RNA isolated from transgenic plants containing the CVMV promoter:uidA fusion gene. Both promoter fragments were able to cause high levels of gene expression in protoplasts isolated from cassava and tobacco cell suspensions. The expression pattern of the CVMV promoters was analyzed in transgenic tobacco and rice plants, and revealed that the GUS staining pattern was similar for each construct and in both plants. The two promoter fragments were active in all plant organs tested and in a variety of cell types, suggesting a near constitutive pattern of expression. In both tobacco and rice plants, GUS activity was highest in vascular elements, in leaf mesophyll cells, and in root tips.
木薯脉花叶病毒（CVMV）是一种双链DNA病毒，可感染木薯植株（木薯），并已被鉴定为属于花椰菜花叶病毒亚组的植物类逆转录病毒。从病毒基因组中分离出两个DNA片段，即位置从-368至+20的388个核苷酸的CVP1和位置从-443至+72的511个核苷酸的CVP2，并将它们与uidA报告基因融合以测试启动子表达。使用从含有CVMV启动子：uidA融合基因的转基因植物中分离的RNA来确定病毒启动子的转录起始位点。两个启动子片段都能够在从木薯和烟草细胞悬浮液中分离的原生质体中引起高水平的基因表达。在转基因烟草和水稻植株中分析了CVMV启动子的表达模式，结果显示每个构建体在两种植物中的GUS染色模式相似。这两个启动子片段在所有测试的植物器官和多种细胞类型中均具有活性，表明其表达模式近乎组成型。在烟草和水稻植株中，GUS活性在维管束、叶肉细胞和根尖中最高。
