Intragenic control of expression of a rice MADS box gene OsMADS1.
OsMADS1 is a rice MADS box gene necessary for floral development. To identify the key cis-regulatory regions for its expression, we utilized transgenic rice plants expressing GUS fusion constructs. Histochemical analysis revealed that the 5.7-kb OsMADS1 intragenic sequences, encompassing exon 1, intron 1, and a part of exon 2, together with the 1.9-kb 5' upstream promoter region, are required for the GUS expression pattern that coincides with flower-preferential expression of OsMADS1. In contrast, the 5' upstream promoter sequence lacking this intragenic region caused ectopic expression of the reporter gene in both vegetative and reproductive tissues. Notably, incorporation of the intragenic region into the CaMV35S promoter directed the GUS expression pattern similar to that of the endogenous spatial expression of OsMADS1 in flowers. In addition, our transient gene expression assay revealed that the large first intron following the CaMV35S minimal promoter enhances flower-preferential expression of GUS. These results suggest that the OsMADS1 intragenic sequence, largely intron 1, contains a key regulatory region(s) essential for expression.
Jeon
Jong-Seong
JS
Plant Metabolism Research Center and Graduate School of Biotechnology, Kyung Hee University, Yongin 446-701, Korea.
Lee
Sichul
S
An
Gynheung
G
D035264:Flowers / Q000166:cytology / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005822:Genetic Vectors / Q000235:genetics; D005966:Glucuronidase / Q000378:metabolism; D007438:Introns / Q000235:genetics; D026161:MADS Domain Proteins / Q000235:genetics* / Q000378:metabolism; D009928:Organ Specificity; D012275:Oryza / Q000166:cytology / Q000235:genetics*; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011993:Recombinant Fusion Proteins / Q000378:metabolism
D026161:MADS Domain Proteins; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D005966:Glucuronidase