Bottom-up effects of fertilization and jasmonate-induced resistance independently affect the interactions between tomato plants and an insect herbivore

Figures & data

Figure 1. Number of eggs laid by Tuta absoluta females (mean ± SE) on tomato plants exposed to four fertilizer regimes (L = low, M = medium, O = optimal, and H = high) with and without induction by methyl jasmonate (MeJA) in two-choice (a), four-choice (b), and multiple-choice tests (c). An asterisk (*) indicates significant differences between treatments. Different letters indicate significant differences among treatments (two-way analysis of variance, P < 0.05). n = 8; n.s, not significant.

Figure 2. Larval survival (percent ± SE) (a), developmental time from egg to pupa (mean days ± SE) (b), and pupal weights (mean mg ± SE) (c) of Tuta absoluta feeding on tomato plants exposed to different fertilizer regimes (L = low, M = medium, O = optimal, and H = high) with and without induction by methyl jasmonate (MeJA). Uppercase letters indicate significant differences between induced and non-induced plants, while lowercase letters indicate significant difference among fertilizer regimes (two-way analysis of variance, P < 0.05). n = 13.

Figure 3. Dry weight (mean g ± SE) (a) and height (mean cm ± SE) (b) of tomato plants exposed to four fertilizer regimens (L = low, M = medium, O = optimal, and H = high) with and without induction by methyl jasmonate (MeJA). Different letters indicate significant differences among treatments (two-way analysis of variance, P < 0.05). n = 8.

Figure 4. Percentage of nitrogen in the soil (mean percent ± SE) exposed to four fertilizer regimens (L = low, M = medium, O = optimal, and H = high) with and without induction by methyl jasmonate (MeJA). Different letters indicate significant differences between treatments (two-way analysis of variance, P < 0.05). n = 5.

Figure 5. Concentrations of nitrogen (a), phosphorus (b), potassium (c), calcium (d), magnesium (e), and sulfur (f) in the leaves of tomato plants (mean g/kg ± SE) exposed to four fertilizer regimens (L = low, M = medium, O = optimal, and H = high) with and without induction by methyl jasmonate (MeJA). Different letters indicate significant differences among treatments (two-way multivariate analysis of variance, P < 0.05). n = 5.

Table 1. Results of two-way analysis of variance (ANOVA) for the effects of fertilizer rates (‘Fertilizer’) and induction by methyl jasmonate (‘MeJA’), and the interaction between these two factors on the levels of nutrients in tomato leaves.

Source of variation	df^a	Nitrogen		Phosporus		Potassium		Calcium		Magnesium		Sulfur
		F	P^b	F	P^b	F	P^b	F	P^b	F	P^b	F	P^b
Fertilizer	3	26.48	< 0.001	43.92	< 0.001	4.03	0.015	29.81	< 0.001	15.42	< 0.001	0.41	0.744
MeJA	1	0.26	0.62	0.29	0.59	2.87	0.1	0.67	0.42	1.06	0.31	0.05	0.82
Fertilizer × MeJA	3	0.16	0.92	1.93	0.9	0.07	0.98	0.14	0.93	0.27	0.85	0.32	0.81

^a Error df = 32.

^b Numbers in bold indicate significant effects at α = 0.05.

Figure 6. Total phenolic content (mean mg de chlorogenic acid/g fresh tissue ± SE) in tomato leaves exposed to four fertilizer regimes (L = low, M = medium, O = optimal, and H = high) with and without induction by methyl jasmonate (MeJA). Different letters indicate significant differences between treatments (two-way analysis of variance, P < 0.05). n = 5.

Figure 7. Amounts (mean ng/g fresh tissue ± SE) of (Z)-3-hexenol (a), α-pinene (b), β-pinene (c), β-myrcene (d), 2-carene (e), α-phellandrene (f), α-terpinene (g), o-cymene (h), β-phellandrene (i), limonene (j), β-ocimene (k), γ-terpinene (l), β-caryophyllene (m), humulene (n), and total volatiles (o) emitted from tomato plants under four fertilizer regimes (L = low, M = medium, O = optimal, and H = high) with and without induction by methyl jasmonate (MeJA). Means followed by different letters indicate significant differences among treatments (GLM, P < 0.05). n = 5.

Table 2. Results of two-way analysis of variance (ANOVA) for the effects of fertilizer rates (‘Fertilizer’) and induction by methyl jasmonate (‘MeJA’), and the interaction between these two factors on the amounts of volatiles emitted from tomato plants.

Compound	Factor	χ^2	P^a	Compound	Factor	χ^2	P^a	Compound	Factor	χ^2	P^a
(Z)-3-Hexenol	Fertilizer	0.054	0.997	α-Phellandrene	Fertilizer	0.763	0.858	β-Ocimene	Fertilizer	2.916	0.405
	MeJA	0.067	0.797		MeJA	7.271	0.007		MeJA	13.678	0.001
	Fertilizer × MeJA	0.222	0.974		Fertilizer × MeJA	2.072	0.558		Fertilizer × MeJA	2.127	0.546
α-Pinene	Fertilizer	1.744	0.627	α-Terpinene	Fertilizer	1.324	0.723	γ-Terpinene	Fertilizer	1.786	0.618
	MeJA	7.743	0.005		MeJA	5.907	0.015		MeJA	4.501	0.034
	Fertilizer × MeJA	1.575	0.665		Fertilizer × MeJA	2.004	0.572		Fertilizer × MeJA	1.137	0.768
β-Pinene	Fertilizer	1.505	0.681	O-cymene	Fertilizer	0.941	0.815	β-Caryophyllene	Fertilizer	1.786	0.901
	MeJA	4.688	0.030		MeJA	10.628	0.001		MeJA	4.045	0.044
	Fertilizer × MeJA	2.811	0.422		Fertilizer × MeJA	0.644	0.886		Fertilizer × MeJA	0.491	0.921
β-Myrcene	Fertilizer	1.633	0.652	β-Phellandrene	Fertilizer	1.233	0.745	Humulene	Fertilizer	0.545	0.909
	MeJA	10.18	0.001		MeJA	6.766	0.009		MeJA	3.579	0.058
	Fertilizer × MeJA	2.88	0.41		Fertilizer × MeJA	1.748	0.626		Fertilizer × MeJA	0.555	0.907
2-Carene	Fertilizer	1.139	0.768	Limonene	Fertilizer	0.902	0.825	Total	Fertilizer	1.129	0.770
	MeJA	6.998	0.008		MeJA	5.433	0.020		MeJA	6.77	0.009
	Fertilizer × MeJA	1.814	0.612		Fertilizer × MeJA	1.668	0.644		Fertilizer × MeJA	1.626	0.653

^a Numbers in bold indicate significant effects at α = 0.05.