Abstract: The isolation of and methods of using a sub-genomic transcript (Sgt) promoter from Mirabilis mosaic virus (MMV) are described. A 333 bp MMV Sgt promoter fragment (sequence?306 to +27 from the transcription start site, TSS) was found to be sufficient for strongest promoter activity. This MMV Sgt promoter fragment shows comparable promoter activity to the MMV FLt promoter both in transgenic plants and in protoplasts. The MMV Sgt promoter also demonstrates much greater activity compared to Cauliflower mosaic virus (CaMV) 19S promoter and 35S promoter. The MMV Sgt promoter fragment and any chimeric gene to which it may be linked are usefull for plant geneic engineering to obtain transgenic plants, plant cells and seeds.

Abstract: A full-length transcript promoter from mirabilis mosaic caulimovirus (MMV) is identified and its DNA sequence given. The promoter functions as a strong and uniform promoter for chimeric genes inserted into plant cells. This strong promoter function is exhibited by histochemical assay in seeds and floral organs and by reproductive scores of transgenic plants including the promoter. The promoter preferably includes a 3′ untranslated region that may be from the MMV itself or from a heterologous source with respect to the promoter. The promoter is used in a chimeric gene and in methods for transforming plant cells to obtain transgenic plants, plant tissues, plant cells and seeds incorporating the MMV promoter. The MMV FLT promoter shows greater activity (14 to 24 fold) than the CaMV 35S promoter. A modified MMV FLt promoter with duplicated enhancer domains shows greater activity (3 fold) than with a single enhancer domain.

Abstract: Use of wild type and modified viral FLt promoters of FMV in the expression of chimeric genes in plant cells. The FLt promoter from FMV is modified with duplicated enhancer domains. The FLt promoter with its single or double enhancer domains is linked to heterologous coding sequences to form chimeric gene constructs. These genes have been shown to be expressed well in plant cells.

Abstract: The isolation, modification and use of wild-type and modified viral FLt promoters of peanut chlorotic streak caulimovirus (PClSV) in the expression of chimeric genes in plant cells. The FLt promoter from PClSV has been modified to have duplicated enhancer domains.