Author Contributions
Conceptualization, A.Z.; Methodology, H.A., A.Z.; Software, A.M.E.-S.; Validation, A.E.-K.; Formal analysis, E.A.A., M.S.S.; Investigation, A.H.A.H. and S.M.K.; Resources, S.S. and Z.A.; Data curation, H.A., A.H.A.H., S.S., S.M.K., M.S.S. and Z.A.; Writing—original draft, H.A., Z.A; Writing—review & editing, H.A., A.H.A.H., S.S., S.M.K., M.S.S. and Z.A., E.A.A.; Visualization, E.A.A., M.S.S.; Supervision, S.S., H.A.; Funding acquisition, S.M.K. All authors have read and agreed to the published version of the manuscript.
Figure 1.
Effect of CNP priming and threshold salinity on fresh weight (A) and dry weight (g/plant) (B) of amaranth sprouts. Data are represented by the means of four replicates ± standard error. Different small letters (a–d) above bars indicate significant differences between control, threshold salinity, and CNP priming (p < 0.05).
Figure 1.
Effect of CNP priming and threshold salinity on fresh weight (A) and dry weight (g/plant) (B) of amaranth sprouts. Data are represented by the means of four replicates ± standard error. Different small letters (a–d) above bars indicate significant differences between control, threshold salinity, and CNP priming (p < 0.05).
Figure 2.
Effect of CNP priming and threshold salinity on Rubisco Enzyme activity (umol PGA/mg. protein. min) (A), total pigment content (B), β-carotene (C), α-carotene (D), α-cryptoxanthin (E), and lutein (mg g−1 FW) (F) of amaranth sprouts. Data are represented by the means of four replicates ± standard error. Different small letters (a–d) above bars indicate significant differences between control, threshold salinity, and CNP priming (p < 0.05).
Figure 2.
Effect of CNP priming and threshold salinity on Rubisco Enzyme activity (umol PGA/mg. protein. min) (A), total pigment content (B), β-carotene (C), α-carotene (D), α-cryptoxanthin (E), and lutein (mg g−1 FW) (F) of amaranth sprouts. Data are represented by the means of four replicates ± standard error. Different small letters (a–d) above bars indicate significant differences between control, threshold salinity, and CNP priming (p < 0.05).
Figure 3.
Effect of CNP priming and threshold salinity on carbohydrate content (mg g−1 FW). Fructose (A), glucose (B), sucrose (C), and total sugar (D) in amaranth sprouts. Data are represented by the means of four replicates ± standard error. Different small letters (a–d) above bars indicate significant differences between control, threshold salinity, and CNP priming (p < 0.05).
Figure 3.
Effect of CNP priming and threshold salinity on carbohydrate content (mg g−1 FW). Fructose (A), glucose (B), sucrose (C), and total sugar (D) in amaranth sprouts. Data are represented by the means of four replicates ± standard error. Different small letters (a–d) above bars indicate significant differences between control, threshold salinity, and CNP priming (p < 0.05).
Figure 4.
Effect of CNP priming and threshold salinity on the antioxidant activity of amaranth sprouts. Antioxidant capacity (FRAP) (A), hydroxyl-radical-scavenger (B), superoxide-anion-scavenger (C), DPPH scavenger activity (D), anti-lipid peroxidation (E). Data are represented by the means of four replicates ± standard error. Different small letters (a–d) above bars indicate significant differences between control, threshold salinity, and CNP priming (p < 0.05).
Figure 4.
Effect of CNP priming and threshold salinity on the antioxidant activity of amaranth sprouts. Antioxidant capacity (FRAP) (A), hydroxyl-radical-scavenger (B), superoxide-anion-scavenger (C), DPPH scavenger activity (D), anti-lipid peroxidation (E). Data are represented by the means of four replicates ± standard error. Different small letters (a–d) above bars indicate significant differences between control, threshold salinity, and CNP priming (p < 0.05).
Figure 5.
The cluster correlation of primary and secondary metabolites of the control and CNPs-primed amaranth sprouts under control or threshold salinity.
Figure 5.
The cluster correlation of primary and secondary metabolites of the control and CNPs-primed amaranth sprouts under control or threshold salinity.
Figure 6.
The cluster heatmap of growth, photosynthetic parameters, primary and secondary metabolites of control and CNPs-primed amaranth sprouts under control or threshold salinity stress conditions. The graph’s horizontal axis shows different treatments for each species and the vertical axis shows different phytocompounds, amino acids, and fatty acids content. Color gradients represent the different values of contents under all treatments compared with that of control. 1 (FW), 2 (DW), 3 (Rebusco), 4 (Total Pigment), 5 (β-carotene), 6 (α-carotene), 7 (α-cryptoxanthin ), 8 (lutein), 9 (Fructose), 10 (Glucose), 11 (Sucrose), 12 (Total sugar), 13 (Glycine), 14 (Lysine), 15 (Histidine), 16 (Alanine), 17 (Arginine), 18 (Ornithine), 19 (Glutamine) 20 (Asparagine), 21 (Isoleucine), 22 (Leucine), 23 (Methionine), 24 (Threonine), 25 (Valine), 26 (Serine), 27 (Phenylalanine), 28 (Glutamic acid), 29 (Aspartate), 30 (Cystine), 31 (Tyrosine), 32 (Oxalic), 33 (Malic acid), 34 (Succinic acid), 35 (Citric acid), 36 (Isobutyric acid), 37 (Fumaric acid), 38 (Myristic acid (C14:0)), 39 (Palmitic acid (C16:0)), 40 (Heptadecanoic acid (C17:0)), 41 (Stearic acid (C18:0)), 42 (Arachidic acid (C20:0)), 43 (Docosanoic acid (C22:0)), 44 (Tricosanoic acid (C23:0)), 45 (Pentacosanoic acid (C25:0)), 46 (Palmitoleic acid (C16:1)), 47 (Heptadecenoic acid (C17:1)), 48 (Oleic acid (C18:1)), 49 (Linoleic acid (C18:2)), 50 (Linolenic acid (C18:3 ω − 3)), 51 (Eicosenoic acid (C20:1)), 52 (Gallic acid), 53 (Caffeic acid), 54 (p-Coumaric acid), 55 (Chicoric acid), 56 (Rosmarinic acid), 57 (Protocatechuic acid), 58 (Quercetin), 59 (Naringenin), 60 (Kaempferol), 61 (Luteolin), 62 (Apigenin), 63 (Naringenin), 64 (Rutin), 65 (Chlorogenic acid), 66 (Alpha-tocopherol), 67 (Beta-tocopherol), 68 (Sigma-tocopherol), 69 (Gama-tocopherol), 70 (Total tocopherols).
Figure 6.
The cluster heatmap of growth, photosynthetic parameters, primary and secondary metabolites of control and CNPs-primed amaranth sprouts under control or threshold salinity stress conditions. The graph’s horizontal axis shows different treatments for each species and the vertical axis shows different phytocompounds, amino acids, and fatty acids content. Color gradients represent the different values of contents under all treatments compared with that of control. 1 (FW), 2 (DW), 3 (Rebusco), 4 (Total Pigment), 5 (β-carotene), 6 (α-carotene), 7 (α-cryptoxanthin ), 8 (lutein), 9 (Fructose), 10 (Glucose), 11 (Sucrose), 12 (Total sugar), 13 (Glycine), 14 (Lysine), 15 (Histidine), 16 (Alanine), 17 (Arginine), 18 (Ornithine), 19 (Glutamine) 20 (Asparagine), 21 (Isoleucine), 22 (Leucine), 23 (Methionine), 24 (Threonine), 25 (Valine), 26 (Serine), 27 (Phenylalanine), 28 (Glutamic acid), 29 (Aspartate), 30 (Cystine), 31 (Tyrosine), 32 (Oxalic), 33 (Malic acid), 34 (Succinic acid), 35 (Citric acid), 36 (Isobutyric acid), 37 (Fumaric acid), 38 (Myristic acid (C14:0)), 39 (Palmitic acid (C16:0)), 40 (Heptadecanoic acid (C17:0)), 41 (Stearic acid (C18:0)), 42 (Arachidic acid (C20:0)), 43 (Docosanoic acid (C22:0)), 44 (Tricosanoic acid (C23:0)), 45 (Pentacosanoic acid (C25:0)), 46 (Palmitoleic acid (C16:1)), 47 (Heptadecenoic acid (C17:1)), 48 (Oleic acid (C18:1)), 49 (Linoleic acid (C18:2)), 50 (Linolenic acid (C18:3 ω − 3)), 51 (Eicosenoic acid (C20:1)), 52 (Gallic acid), 53 (Caffeic acid), 54 (p-Coumaric acid), 55 (Chicoric acid), 56 (Rosmarinic acid), 57 (Protocatechuic acid), 58 (Quercetin), 59 (Naringenin), 60 (Kaempferol), 61 (Luteolin), 62 (Apigenin), 63 (Naringenin), 64 (Rutin), 65 (Chlorogenic acid), 66 (Alpha-tocopherol), 67 (Beta-tocopherol), 68 (Sigma-tocopherol), 69 (Gama-tocopherol), 70 (Total tocopherols).
Table 1.
Effect of CNP priming and threshold salinity and their interaction on the amino acid content (mg/gFW) of amaranth sprouts.
Table 1.
Effect of CNP priming and threshold salinity and their interaction on the amino acid content (mg/gFW) of amaranth sprouts.
Amino Acids | Control | Threshold Salinity | CNPs | CNPs + Threshold Salinity |
---|
Glycine | 91.30 ± 4.7 b | 112.39 ± 4.04 a | 96.00 ± 4.33 b | 118.8 ± 5.2 a |
Lysine | 3.85 ± 0.38 c | 5.63 ± 0.61 b | 6.49 ± 1.02 a | 5.83 ± 0.71 b |
Histidine | 1.73 ± 0.46 c | 2.67 ± 0.63 b | 3.57 ± 0.58 a | 3.89 ± 0.5 a |
Alanine | 16.04 ± 0.65 c | 18.87 ± 0.7 b | 18.40 ± 0.69 b | 22.1 ± 1.8 a |
Arginine | 1.43 ± 0.24 b | 1.82 ± 0.7 ab | 2.07 ± 0.20 a | 2.11 ± 0.3 a |
Ornithine | 0.69 ± 0.13 c | 0.89 ± 0.1 bc | 1.30 ± 0.3 b | 1.93 ± 0.1 a |
Glutamine | 2.8 ± 0.65 a | 2.54 ± 0.1 b | 2.48 ± 0.01 b | 3.5 ± 0.3 a |
Asparagine | 1.93 ± 0.20 c | 1.95 ± 0.08 c | 2.87 ± 0.38 b | 4.9 ± 0.3 a |
Isoleucine | 0.66 ± 0.03 b | 0.60 ± 0.04 b | 1.16 ± 0.04 a | 1.28 ± 0.08 a |
Leucine | 0.14 ± 0.03 c | 0.21 ± 0.05 b | 0.21 ± 0.05 b | 0.28 ± 0.07 a |
Methionine | 0.16 ± 0.07 c | 0.22 ± 0.04 c | 0.29 ± 0.15 b | 0.44 ± 0.2 a |
Threonine | 0.63 ± 0.45 c | 0.50 ± 0.39 c | 1.05 ± 0.67 b | 1.26 ± 0.79 a |
Valine | 1.26 ± 0.21 b | 1.29 ± 0.08 c | 1.06 ± 0.18 a | 2.1 ± 0.06 a |
Serine | 1.02 ± 0.40 a | 1.07 ± 0.19 b | 0.97 ± 0.37 b | 1.78 ± 0.5 |
Phenylalanine | 1.40 ± 0.40 ab | 0.96 ± 0.48 b | 1.50 ± 0.57 a | 2.13 ± 0.2 a |
Glutamic acid | 1.07 ± 0.05 c | 1.17 ± 0.04 c | 1.44 ± 0.05 b | 1.78 ± 0.2 a |
Aspartate | 0.22 ± 0.01 c | 0.38 ± 0.0 b | 0.35 ± 0.11 b | 0.48 ± 0.01 a |
Cystine | 0.27 ± 0.21 d | 0.51 ± 0.40 c | 0.73 ± 0.4 ab | 0.93 ± 0.3 a |
Tyrosine | 0.46 ± 0.03 d | 0.68 ± 0.06 c | 0.98 ± 0.01 b | 1.6 ± 0.03 a |
Table 2.
Effect of CNP priming and threshold salinity on the organic acids content (mg/gFW) of amaranth sprouts.
Table 2.
Effect of CNP priming and threshold salinity on the organic acids content (mg/gFW) of amaranth sprouts.
Metabolites/Treatments | Control | Threshold Salinity | CNPs | CNPs + Threshold Salinity |
---|
Oxalic | 3.1 ± 0.17 b | 3.08 ± 0.3 a | 3.1 ± 0.2 ab | 3.67 ± 0.20 a |
Malic | 14.4 ± 1.02 b | 17.6 ± 1.0 b | 15.2 ± 1.1 b | 29.1 ± 0.4 a |
Succinic | 6.42 ± 0.27 c | 8.7 ± 0.06 b | 6.4 ± 0.26 c | 11.6 ± 0.6 a |
Citric | 6.26 ± 0.39 b | 5.49 ± 0.0 b | 2.7 ± 0.15 c | 8.9 ± 0.60 a |
Isobutyric | 4.02 ± 0.24 b | 5.91 ± 0.3 a | 4.0 ± 0.25 b | 4.9 ± 0.5 ab |
Fumaric | 0.32 ± 0.02 c | 0.52 ± 0.03 b | 0.3 ± 0.03 c | 0.86 ± 0.4 a |
Table 3.
Effect of CNP priming and threshold salinity on the fatty acids content (mg/gFW) of amaranth sprouts.
Table 3.
Effect of CNP priming and threshold salinity on the fatty acids content (mg/gFW) of amaranth sprouts.
Metabolites/Treatments | Control | Threshold Salinity | CNPs | CNPs + Threshold Salinity |
---|
Myristic (C14:0) | 0.61 ± 0.01 b | 1.21 ± 0.03 ab | 0.51 ± 0.01 b | 1.43 ± 0.5 a |
Palmitic (C16:0) | 24.3 ± 2.3 c | 38.1 ± 2.75 b | 14.1 ± 1.43 d | 52.5 ± 5 a |
Heptadecanoic (C17:0) | 0.06 ± 0.01 b | 0.08 ± 0.0 b | 0.05 ± 0.01 b | 0.15 ± 0.01 a |
Stearic (C18:0) | 2.3 ± 0.35 b | 2.55 ± 0.1 b | 1.98 ± 0.32 c | 3.94 ± 0.2 a |
Arachidic (C20:0) | 1.72 ± 0.10 a | 1.12 ± 0.0 b | 0.80 ± 0.04 c | 1.71 ± 0.2 a |
Docosanoic (C22:0) | 0.78 ± 0.17 a | 0.71 ± 0.03 a | 0.50 ± 0.07 b | 0.92 ± 0.13 a |
Tricosanoic (C23:0) | 0.04 ± 0.01 b | 0.05 ± 0.0 b | 0.04 ± 0.01 b | 0.13 ± 0.0 a |
Pentacosanoic (C25:0) | 0.00 ± 0.00 b | 0.012 ± 0.00 a | 0.00 ± 0.0 b | 0.02 ± 0.00 a |
Palmitoleic (C16:1) | 0.12 ± 0.03 c | 0.16 ± 0.01 b | 0.13 ± 0.04 c | 0.32 ± 0.05 a |
Heptadecenoic (C17:1) | 0.22 ± 0.06 c | 0.31 ± 0.07 b | 0.09 ± 0.02 d | 0.46 ± 0.06 a |
Oleic (C18:1) | 52.9 ± 4.6 b | 54.0 ± 2.0 ab | 34.5 ± 13.5 b | 71.1 ± 3.4 a |
Linoleic (C18:2) | 0.03 ± 0.00 c | 0.05 ± 0.00 b | 0.01 ± 0.00 d | 0.07 ± 0.a |
Linolenic(C18:3 ω − 3) | 0.02 ± 0.00 b | 0.05 ± 0.00 a | 0.01 ± 0.00 c | 0.06 ± 0.00 a |
Eicosenoic (C20:1) | 1.37 ± 0.19 c | 1.9 ± 0.12 b | 0.66 ± 0.13 d | 2.5 ± 0.34 a |
Tetracosenoic (C24:1) | 0.02 ± 0.00 a | 0.03 ± 0.0 a | 0.01 ± 0.00 b | 0.015 ± 0.0 b |
Table 4.
Effect of CNP priming and threshold salinity on the level of phenols and flavonoids (mg/gFW) of amaranth sprouts.
Table 4.
Effect of CNP priming and threshold salinity on the level of phenols and flavonoids (mg/gFW) of amaranth sprouts.
Metabolites/Treatments | Control | Threshold Salinity | CNPs | CNPs + Threshold Salinity |
---|
Gallic acid | 2.32 ± 0.11 b | 3.5 ± 0.18 a | 3.37 ± 0.08 a | 3.17 ± 0.29 a |
Caffeic acid | 5.0 ± 0.12 b | 7.97 ± 0.34 a | 6.78 ± 0.17 a | 6.51 ± 0.4 ab |
p-Coumaric acid | 2.31 ± 0.03 b | 3.42 ± 0.17 a | 2.860 ± 0.08 ab | 2.8 ± 0.19 ab |
Chicoric acid | 2.47 ± 0.02 b | 3.61 ± 0.15 a | 3.080 ± 0.03 a | 3.280 ± 0.04 a |
Rosmarinic acid | 7.72 ± 0.17 b | 10.4 ± 0.04 a | 8.77 ± 0.19 b | 10.46 ± 0.06 a |
Protocatechuic acid | 3.25 ± 0.09 b | 4.45 ± 0.08 a | 3.87 ± 0.12 b | 4.36 ± 0.09 a |
Quercetin | 1.880 ± 0.07 a | 2.6 ± 0.09 a | 2.15 ± 0.09 a | 2.62 ± 0.04 a |
Naringenin | 0.85 ± 0.02 a | 1.28 ± 0.08 a | 1.09 ± 0.06 a | 1.22 ± 0.04 a |
Kaempferol | 12.5 ± 0.05 c | 21.6 ± 0.53 a | 15.7 ± 0.93 b | 20.9 ± 0.57 a |
Luteolin | 2.28 ± 0.09 b | 3.8 ± 0.10 a | 3.10 ± 0.02 a | 3.94 ± 0.12 a |
Apigenin | 0.07 ± 0.00 b | 0.11 ± 0.00 a | 0.09 ± 0.00 a | 0.11 ± 0.00 a |
Naringenin | 0.10 ± 0.0 b | 0.16 ± 0.01 a | 0.140 ± 0.01 | 0.150 ± 0.0 a |
Rutin | 0.03 ± 0.00 a | 0.04 ± 0.00 a | 0.03 ± 0.00 a | 0.03 ± 0.00 a |
Chlorogenic acid | 0.58 ± 0.02 c | 0.92 ± 0.04 a | 0.75 ± 0.01 b | 0.77 ± 0.06 b |
Table 5.
Effect of CNP priming and threshold salinity on the tocopherol (Vit E. mg/gFW) of amaranth sprouts.
Table 5.
Effect of CNP priming and threshold salinity on the tocopherol (Vit E. mg/gFW) of amaranth sprouts.
Metablites/Treatments | Control | Threshold Salinity | CNPs | CNPs + Threshold Salinity |
---|
Alpha-tocopherol | 1.90 ± 0.22 c | 2.7 ± 0.20 b | 2.28 ± 0.10 b | 5.5 ± 0.9 a |
Beta-tocopherol | 0.32 ± 0.04 c | 0.76 ± 0.05 b | 0.39 ± 0.02 c | 0.91 ± 0.09 a |
Sigma-tocopherol | 0.08 ± 0.01 c | 0.12 ± 0.0 b | 0.10 ± 0.00 c | 0.18 ± 0.01 a |
Gama-tocopherol | 0.00 ± 0.00 a | 0.00 ± 0.00 a | 0.00 ± 0.00 a | 0.00 ± 0.00 a |
Total tocopherols | 2.30 ± 0.27 c | 3.58 ± 0.6 b | 2.76 ± 0.12 c | 6.59 ± 0.9 a |
Table 6.
Effect of CNP priming and threshold salinity on the anti-microbial activity (zone inhibition diameter (mm)) of amaranth sprouts.
Table 6.
Effect of CNP priming and threshold salinity on the anti-microbial activity (zone inhibition diameter (mm)) of amaranth sprouts.
Microorganism/Treatments | Control | Threshold Salinity | CNPs | CNPs + Threshold Salinity |
---|
Staphylococcus saprophyticus | 13.55 ± 0.75 c | 21.28 ± 1.72 a | 19.64 ± 0.10 b | 21.74 ± 0.84 a |
Staphylococcus epidermidis | 16.96 ± 0.80 c | 24.92 ± 1.60 b | 25.50 ± 0.30 a | 26.85 ± 1.28 a |
Enterococcus faecalis | 21.85 ± 0.88 b | 33.74 ± 0.77 a | 30.77 ± 1.32 a | 22.78 ± 5.53 b |
Streptococcus salivarius | 18.90 ± 0.92 c | 33.34 ± 3.28 a | 21.99 ± 0.97 b | 25.51 ± 1.17 b |
Escherichia coli | 22.90 ± 0.48 c | 27.02 ± 1.59 b | 25.89 ± 0.97 b | 30.70 ± 1.54 a |
Salmonella typhimurium | 26.16 ± 0.86 b | 39.19 ± 0.58 a | 27.30 ± 1.05 b | 34.04 ± 1.20 a |
Pseudomonas aeruginosa | 24.66 ± 1.06 c | 33.54 ± 1.02 b | 28.31 ± 1.22 c | 35.17 ± 1.02 a |
Proteus vulgaris | 22.46 ± 0.85 c | 27.67 ± 3.13 b | 29.45 ± 0.48 a | 29.05 ± 1.42 a |
Enterobacter aerogenes | 14.04 ± 0.63 c | 25.16 ± 0.78 a | 21.50 ± 0.49 b | 21.12 ± 0.88 b |
Salmonella typhimurium | 8.00 ± 0.36 c | 14.22 ± 0.69 a | 11.60 ± 0.26 b | 13.70 ± 0.49 a |
Candida albicans | 9.84 ± 0.41 c | 15.69 ± 0.06 ab | 14.00 ± 0.52 b | 18.49 ± 1.21 a |
Aspergillus flavus | 10.75 ± 0.36 c | 18.56 ± 0.75 a | 14.57 ± 0.75 b | 17.27 ± 0.48 a |