Development of transgenic rice plants overexpressing the Arabidopsis H ⁺/Ca²⁺ antiporter CAX1 gene

The gene of the Arabidopsis thaliana H⁺/Ca²⁺ transporter, CAX1 (cation exchanger 1) was introduced into Japonica cultivars of rice (Ilpumbyeo) by Agrobacterium-mediated transformation, and a large number of transgenic plants were produced. The neomycin phosphotransferase II (NPTII) gene was used as a selectable marker. The activity of neomycin phosphotransferase could be successfully detected in transgenic rice callus. The introduction of the CAX1 gene was also proven by PCR using CAX1-specific oligonucleotide primers in regenerated plants. Stable integration and expression of the CAX1 gene in T₀ plants and T₁ progeny were confirmed by DNA hybridization, Northern blot analysis, and luminescent analysis.