Figure 1.

A, Structure of the chimeric gene possessing an antisense DNA of NDP kinase. The heat shock promoter HSP81-1 was fused to the full-length NDP kinase cDNA and the termination sequences of the nopaline synthase gene. The cassette was then cloned into XbaI and HindIII restriction sites of the vector pHTS6.1. The original 5′ to 3′ direction of NDP kinase cDNA is indicated by the arrow. B, Southern-blot analysis of T₃ transgenic rice plants. Genomic DNA was digested with XbaI and then subjected to electrophoresis followed by hybridization with the DIG-labeled NDP kinase cDNA probe. C, Northern-blot analysis of transgenic rice plants. Total RNA (10 μg) extracted from plant shoots (2-month-old) was loaded in each lane, and then hybridized with a DIG-labeled NDP kinase antisense probe. Arrow points to a position corresponding to approximately 700 nt. D, NDP kinase activity comparison of 12 different transgenic rice lines. Shoots of 12-d-old seedlings of each line (at 25°C) were assayed for NDP kinase enzyme activity. Data for individual lines represent the means ± se of three preparations.