Effects of FC on PR gene expression. A, PR gene
expression is induced by FC, as shown by RNA gel blots showing
expression of PR1 (accession no. M69248), acidic PR
glucanase (PR2A, accession no. M80604), acidic PR
chitinase (PR3A, accession no. Z15141), basic PR
chitinase (PR3B, accession no. Z15140), and ACC oxidase
(ACO, accession no. A35021) in tomato leaves pretreated
with either 1 μm FC or water for 30 min. Hybridization to
a 28S rRNA probe is shown as a loading control. The data are
representative of at least three independent experiments. B,
Synergistic effects of FC and avirulence elicitor on PR gene
expression, as shown by RNA gel blots showing expression of acidic PR
chitinase (PR3A), basic PR chitinase
(PR3B), and ACO in tomato cotyledons
24 h after injection with combinations of 1 μm FC
and intercellular fluid extracts containing (Avr9+) or lacking (Avr9−)
the Avr9 elicitor.