Abstract
We inserted a T-DNA containing a tetramer of the CaMV 35S enhancer coupled with the CaMV 35S minimum promoter into Nipponbare and generated 13,000 activation-tagged rice lines. We selected a Short grain 1 (Sg1) mutant that also showed a semi-dwarf phenotype. Sg1 phenotype was linked to the T-DNA insertion. A full-length cDNA, about 1.4 kb downstream of the inserted T-DNA, was highly expressed in the leaf blades of Sg1 but it was not detected in those of wild-type (WT) plants. In WT plants, this cDNA was expressed mainly in young panicles with developing lemma and palea primordia. The deduced protein shows no homology with other known proteins. These results strongly suggest that transcriptional activation of this novel gene caused the Sg1 phenotype. Transgenic rice lines overexpressing the cDNA are being generated for further characterization.
