Young tomato psyllids induce salicylic acid regulated transcripts.

Transcript abundance (mean ± SE) for PAL5 and PR1 in fully expanded leaves exposed to 4 different developmental stages of tomato psyllid (1^st–2^nd, 3^rd, 5^th, and adult) after 24 hr of insect feeding: (A) PAL5. (B) PR1. Significantly different regulation from undamaged controls (dashed lines = control transcript abundance) is indicated by an asterisk and significant differences between insect developmental stages are indicated by letters (P<0.05).