Total RNA was prepared from the tomato tissues using
TRIzol reagent (Invitrogen, Life Technologies, California,
US) following the manufacturer’s instructions.
First-strand cDNA was synthesised from 5 μg of total
RNA using Moloney Murine Leukemia Virus reverse
transcriptase (Promega Biotech Ibérica, Madrid, Spain)
and an oligo(dT)18 primer. The reverse transcriptase
reaction mix (5 μL) was subject to PCR using a
Perkin-Elmer (Madrid, Spain) thermocycler: 94 °C denaturation
for 30 s, followed by 25 (for RPL2) or 30 cycles
of 94 °C for 30 s, 50 °C for 1 min, 72 °C for 1 min,
and a final extension of 72 °C for 15 min. The primer
sequences used for tomato for amplification of PR1
were 5´-CACTAAACCTAAAGAAAAATGG-3´ (forward
primer) and 5´-GTGGAATTATTCATATTAGC-
3´ (reverse primer) (Tornero et al. 1997). The primer