Figure 1.

Properties of transgenic chrysanthemum. (A) Expression of transcripts for caffeine biosynthetic genes. Total RNA was isolated from leaves of 1-month transgenic lines indicated and subjected to RT-PCR using the gene specific primers for CaXMT, CaMXMT1 and CaDXMT1. Since the cassette contains NPTII and HPT genes, their expression was also shown. As the internal standard, 18s rRNA was used. (B) Quantification of caffeine content. One g of fresh leaf tissue of indicated lines was processed and subjected to HPLC analysis. Caffeine amount is expressed in mg per g of fresh weight (FW). Three independent samples were measured and the standard deviation is shown by the error bar. (C) Pathogen symptom. Detached healthy mature leaf of indicated lines was inoculated with B. cinerea at the concentration of 1 × 10⁵ spores ml⁻¹, incubated at 20°C for 15 days and photographed. (D) Quantification of lesion. Diameter of the necrotic lesion was measured 15 days after inoculation. More than 12 independent samples were assayed, and values were treated by the t test to show the significance of probability (p < 0.05).