Comparison of nutrient uptake and antioxidative response among four Labiatae herb species under salt stress condition

Figures & data

Figure 1. Effect of salinity treatment on dry weight in basil, sage, thyme, and oregano.

Different large alphabetic letters and * indicate significant differences in total dry weight and dry weight in each part between control and salinity treatment in the same species (t-test; p < 0.05). 0 Na; standard nutrient solution (Control), 50 Na; standard nutrient solution containing 50 mM NaCl (Salinity treatment). Error bars in the figure indicate standard errors of four replications.

Figure 2. Effect of salinity treatment on leaf water content in basil, sage, thyme, and oregano.

** indicates significant differences between control and salinity treatment in the same species (t-test; p < 0.01). 0 Na; standard nutrient solution (Control), 50 Na; standard nutrient solution containing 50 mM NaCl (Salinity treatment). Error bars in the figure indicate standard errors of four replications.

Figure 3. Effect of salinity treatment on leaf chlorophyll (a + b) content in basil, sage, thyme, and oregano.

** indicates significant difference between control and salinity treatment in the same species (t-test; p < 0.01). 0 Na; standard nutrient solution (Control), 50 Na; standard nutrient solution containing 50 mM NaCl (Salinity treatment). Error bars in the figure indicate standard errors of four replications.

Figure 4. Effect of salinity treatment on leaf MDA content in basil, sage, thyme, and oregano.

* and ** indicate significant differences between control and salinity treatment in the same species (t-test; p < 0.05 and p < 0.01). 0 Na; standard nutrient solution (Control), 50 Na; standard nutrient solution containing 50 mM NaCl (Salinity treatment). Error bars in the figure indicate standard errors of four replications.

Figure 5. Effect of salinity treatment on leaf H₂O₂ content in basil, sage, thyme, and oregano.

There was no significant difference (t-test; p < 0.05) between control and salinity treatment in the same species. 0 Na; standard nutrient solution (Control), 50 Na; standard nutrient solution containing 50 mM NaCl (Salinity treatment). Error bars in the figure indicate standard errors of four replications.

Figure 6. Effect of salt treatment on leaf antioxidative enzyme activities in basil, sage, thyme, and oregano.

(a) CAT activity, (b) superoxide dismutase activity (SOD), (c) APX activity, (d) GR activity. * and ** indicate significant differences between control and salinity treatment in the same species (t-test; p < 0.05 and p < 0.01). 0 Na; standard nutrient solution (Control), 50 Na; standard nutrient solution containing 50 mM NaCl (Salinity treatment). Error bars in the figure indicate standard errors of four replications.

Table 1. Effect of salinity treatment on nutrient contents in leaf blades, stems and roots of basil, sage, thyme, and oregano.

			Na	K	Mg		Na distribution rate	K distribution rate
Species	Treatments	Parts	(mg g^−1 DW)			Na/K	(%)
Basil	0 Na	Leaf blades	0.09 ± 0.03b	25.15 ± 0.46b	9.51 ± 0.11a*	0.004 ± 0.001b	1.5 ± 0.50c	4.08 ± 1.30a
		Stems	0.52 ± 0.06b	41.19 ± 2.12a**	6.58 ± 0.50b**	0.013 ± 0.002b	5.9 ± 0.58b	45.2 ± 2.17a**
		Roots	10.93 ± 0.43a	17.01 ± 0.93c**	3.78 ± 0.18c**	0.650 ± 0.053a	92.6 ± 1.06a**	14.1 ± 1.00b**
	50 Na	Leaf blades	7.03 ± 1.02b**	26.93 ± 1.81a	7.26 ± 0.42a	0.257 ± 0.023b**	18.0 ± 2.43b**	71.01.84a**
		Stems	35.74 ± 0.87a**	16.53 ± 1.78b	2.47 ± 0.24b	2.243 ± 0.257b**	52.8 ± 3.53a**	25.0 ± 2.22b
		Roots	30.10 ± 3.02a**	3.97 ± 0.22c	1.97 ± 0.16b	7.757 ± 1.129a**	29.2 ± 5.41b	4.0 ± 0.65c
Sage	0 Na	Leaf blades	0.59 ± 0.08c	9.51 ± 0.54a	6.34 ± 0.10a*	0.063 ± 0.009b	16.2 ± 1.72b	64.3 ± 2.16a
		Stems	1.90 ± 0.36b	8.37 ± 0.98ab	4.48 ± 0.29b	0.223 ± 0.017b	19.1 ± 2.04b	20.9 ± 1.34b
		Roots	7.55 ± 0.31a	7.09 ± 0.53b	2.61 ± 0.10c*	1.083 ± 0.094a	64.7 ± 2.96a*	14.8 ± 0.92c
	50 Na	Leaf blades	21.63 ± 0.93**	9.43 ± 0.16a	5.42 ± 0.22a	2.295 ± 0.107b**	51.7 ± 5.91a*	68.5 ± 3.14a
		Stems	25.10 ± 1.29**	6.99 ± 0.45b	4.18 ± 0.31b	3.658 ± 0.377b**	21.2 ± 2.24b	18.0 ± 1.39b
		Roots	27.52 ± 6.15	4.40 ± 0.57c	1.91 ± 0.05c	6.037 ± 1.128a*	27.2 ± 8.10b	13.4 ± 2.99b
Thyme	0 Na	Leaf blades	1.46 ± 0.17b	36.95 ± 1.36b**	5.07 ± 0.26a**	0.040 ± 0.005b	41.0 ± 1.67a	44.1 ± 1.38a
		Stems	1.56 ± 0.15b	43.38 ± 1.50a**	3.69 ± 0.20b*	0.036 ± 0.003b	36.8 ± 2.53a	46.2 ± 1.37a
		Roots	3.68 ± 0.35a	39.70 ± 0.53ab**	3.03 ± 0.08c**	0.092 ± 0.008a	22.1 ± 4.17b	9.7 ± 0.66b
	50 Na	Leaf blades	25.73 ± 2.61**	19.38 ± 0.47a	2.84 ± 0.11a	1.337 ± 0.154**	44.7 ± 1.53a	48.5 ± 1.56a
		Stems	26.71 ± 2.66**	17.34 ± 0.92ab	2.58 ± 0.13ab	1.563 ± 0.193**	41.7 ± 1.64a	40.3 ± 1.74b
		Roots	26.71 ± 0.28**	15.99 ± 0.46b	2.36 ± 0.10b	1.673 ± 0.032**	13.6 ± 2.07b	112. ± 0.47c
Oregano	0 Na	Leaf blades	1.89 ± 0.66b	17.97 ± 0.25b	3.66 ± 0.18	0.104 ± 0.035b	53.3 ± 6.80a	57.7 ± 0.44a
		Stems	1.86 ± 0.27b	28.47 ± 0.64a**	4.03 ± 0.17**	0.066 ± 0.010b	19.0 ± 3.82b	28.6 ± 0.39b**
		Roots	5.23 ± 0.27a	27.61 ± 0.59a**	3.92 ± 0.11	0.190 ± 0.014a	27.6 ± 5.88b*	13.7 ± 0.52c**
	50 Na	Leaf blades	39.21 ± 1.30b**	33.06 ± 0.58a**	4.29 ± 0.06a*	1.189 ± 0.057b**	52.4 ± 0.89a	83.8 ± 1.50a**
		Stems	67.00 ± 0.62a**	11.95 ± 1.17b	2.27 ± 0.11b	5.783 ± 0.601a**	43.4 ± 0.88	14.6 ± 1.39b
		Roots	24.13 ± 1.92c**	4.55 ± 0.45c	3.84 ± 0.55a	5.459 ± 0.736a**	4.2 ± 0.37c	1.5 ± 0.22c

Each data represent a mean of four replications ± standard error. Different alphabets indicate significant differences among parts in the same species (Duncan; p < 0.05). * and ** indicate significant differences between control and salinity treatment in the same parts and species (t-test; p < 0.05 and p < 0.01), respectively. 0 Na; standard nutrient solution (Control), 50 Na; standard nutrient solution containing 50 mM NaCl (Salinity treatment). No letter indicates no significant difference. For each part, Na or K distribution rate was calculated as a percentage of the total Na or K nutrient amount (mg plant⁻¹) of the plant.