Table 1.

Concentrations (µg·g·FW⁻¹) of volatile compounds released from tomato plants treated or not treated (control) with salicyclic acid (SA) ^a.

Volatile Compound	Control Plants b	SA-Treated Plants c
3-Hexenal	0.422 ± 0.112 A	0.561 ± 0.098 A
3-Hexen-1-ol	0.130 ± 0.012 A	0.376 ± 0.070 A
α-Pinene	0.029 ± 0.007 A	0.245 ± 0.027 B
β-Myrcene	0.819 ± 0.197 A	1.826 ± 0.864 A
β-Phellandrene	0.089 ± 0.037 A	0.513 ± 0.099 B
β-Caryophyllene	0.939 ± 0.303 A	1.612 ± 0.072 A
ρ-Cymene	0.325 ± 0.069 A	1.188 ± 0.092 B
α-Phellandrene	2.935 ± 0.096 A	2.485 ± 0.151 A
α-Humulene	0.073 ± 0.020 A	0.307 ± 0.037 B
Methyl salicylate	n.d.	3.428 ± 0.141
δ-Limonene	n.d.	2.420 ± 0.146

^a Values are means ± SE. Volatiles were compared by horizontal not vertical direction. For each compound, different uppercase letters (A and B) indicate significant differences between SA-treated plants and control plants (LSD test at p < 0.05). n.d.: not detected; ^b Plants were sprayed with water (containing 1 mL ethanol and 10% Tween 20) 24 h before volatiles were trapped; ^c Plants were sprayed with 1 mM SA 24 h before volatiles were trapped.