Analysis of a promoter for the NADH–glutamate synthase gene in rice (Oryza sativa): cell type-specific expression in developing organs of transgenic rice plants

The entire 3.7 kbp 5´-upstream region (-2840 to +886) from the translational start codon of NADH- glutamate synthase (NADH-GOGAT, EC 1.4.1.14) gene from rice (Oryza sativa L.) or the region sequentially deleted from the 5´-end was fused with the β-glucuronidase (GUS) reporter gene. The chimeric gene was introduced into calli derived from rice scutellum via Agrobacterium tumefaciens-mediated transformation and tissue-specific GUS activity determined in T0 generations. When the entire region was fused, GUS activity was detected in vascular bundles of the developing leaf blade and in dorsal and lateral vascular bundles of developing grains. This corresponds with our previous immunodetection of NADH-GOGAT protein (Hayakawa et al., Planta 193, 455-460, 1994). A series of deletion experiments showed that a 149-nucleotide region between -142 and +7 was essential for promoter activity in the NADH-GOGAT gene.