[Inheritance, expression and armyworm resistance of protease inhibitor II gene (Pin II) driven by different promoters in transgenic rice].

The inheritance of rice lines transformed by protease inhibitor II gene under control of different promoters was investigated by analysis of hygromycin resistance, PCR and Southern blot. For segregation patterns of foreign gene, 68.4% of the transgenic rice plants were conformed to a Mendelian ratio and in which the rate of transgenic plants with single copy was 63.6%. Quantitative analysis of Pin II protein expressed in transgenic rice plants showed that Pin II protein in fresh leaves was 160 microg/g for Act-Pin II-2x, 176 microg/g for Ubi-Pin II-2x, and 104 microg/g for PIN5'-Pin II-4x separately while in control rice plants was only 20 microg/g. The inhibitory activity against tryspin of Pin II gene driven by Actl and Ubi promoter reached 37.7% and 43.1%, much higher than that driven by PIN5' (29.2%). Bioassay for insect resistance to armyworm (Pseudaletia separata Walker) revealed that transgenic plants had increased their resistance to the pest but there was not significantly different from controls, and also there was no correlation between insect resistance to armyworm and quantity of Pin II protein as well as promoters in transgenic rice.