A, Construction of transgenic plants overexpressing CSase. 35S-P, Cauliflower mosaic virus 35S RNA promoter; CSase, CSase transgene from spinach; TP, the chloroplast-targeting transit peptide of pea RUBISCO. B, Northern-blot analysis of total RNA of transgenic plants. SR1, Non-transformed tobacco (cv SR1); 35S-β-glucuronidase (GUS), tobacco plants transformed with a bacterial UidA gene encoding GUS using as a negative control.