Sublethal Heavy Metal Stress Stimulates Innate Immunity in Tomato

Table 1

Effect of CuCl₂ on the production of defense and antioxidative enzymes in tomato plants. Values represent mean ± SE of three separate experiments, each in triplicate.

Enzymes	Control	Concentrations of CuCl2
		1 mM	2.5 mM	5 mM
Peroxidase (PO) µmol min^−1 g^−1 protein	188.45 ± 14.01^c	267.96 ± 7.90^b	334.51 ± 9.23^a	239.55 ± 9.10^b
Polyphenol oxidase (PPO) U min^−1 g^−1 protein	29.44 ± 1.12^c	32.25 ± 2.08^c	54.77 ± 2.37^a	40.855 ± 1.47^b
Phenylalanine ammonia-lyase (PAL); nmol of trans-cinnamic acid min^−1 g^−1 protein	94.23 ± 4.39^d	123.55 ± 6.95^c	165.22 ± 3.12^a	140.38 ± 3.78^b
β-1,3 Glucanase; mol glucose produced min^−1 g^−1 protein	26.38 ± 2.29^d	40.1 ± 1.13^c	53.25 ± 2.34^a	47.1 ± 1.39^b
Catalase (CAT) mmol min^−1 g^−1 protein	6.83 ± 0.30^d	11.74 ± 0.61^c	15.09 ± 0.47^b	17.67 ± 0.56^a
Ascorbate peroxidase (APX) mol min^−1 g^−1 protein	0.177 ± 0.021^c	0.321 ± 0.024^b	0.408 ± 0.025^a	0.253 ± 0.014^b

Sharing the same letter are not significantly different () using Duncan’s multiple range test.