Fig 7.

Detection of internalized TV RNA in romaine lettuce treated with RNase. Amounts of 100 μl of processed lettuce samples from the experiment whose results are shown in Fig. 6 were treated with 5 μg of RNase at 37°C for 1 h. The RNA was extracted using an RNeasy kit (Qiagen), followed by real-time RT-PCR. Results are reported as RNA copies/g. Data points are the averages of three replicates. Error bars represent ±1 standard deviation. Statistical differences (P < 0.05) are indicated by an asterisk.