Abstract
Rice (Oryza sativa L.) plants possess three homologous but distinct genes for cytosolic glutamine synthetase (GS1): these are OsGS1;1, OsGS1;2 and OsGS1;3. To understand an individual role of three GS1 isoenzymes during germination, expression profiles of these genes were analyzed using real-time PCR. Localization of these gene products in situ were also performed.
GS1 protein and its activity were detected following the germination for 3 days. In contrast, GS2 was not detected. Transgenic rice expressing GUS under the control of corresponding GS1 promoter showed that OsGS1;1 genes was active in the shoots. OsGS1;2 and OsGS1;3 genes were also active in the scutellum and the aleurone layers, respectively. Individual function of each GS1 isoenzyme during gerimination will be discussed.
