Table 1.
Shoot dry matter (g plant−1), photosynthetic pigment content (g m−2), relative water content (RWC; %), the two-way analysis of variance and the coefficient of variance of amaranth plants grown under low nitrogen and sufficient water supply (LN+W), low nitrogen and low water supply (LN-W), high nitrogen and sufficient water supply (HN+W), and high nitrogen and low water supply (HN-W) after six days of water stress and 24 h of rehydration. the values are the mean±SE of 10, 6, and 5 plants for shoot dry matter, photosynthetic pigments, and RWC, respectively.
Fig 1.
Stomatal conductance (gs, A), transpiration (E, B), photosynthesis (A, C) and intercellular CO2 concentration (Ci, D) of amaranth plants grown under low nitrogen and sufficient water supply (LN+W), low nitrogen and low water supply (LN-W), high nitrogen and sufficient water supply (HN+W), and high nitrogen and low water supply (HN-W) after six days of water stress.
The values are the mean±SE of seven plants. The means followed by the same small letters (for W at a given N level) and capital letters (for N at a given W supply) are not significantly different at P = 0.05.
Table 2.
The coefficient of variation and two-way ANOVA on several characteristics of amaranth plants grown under low nitrogen and sufficient water supply (LN+W), low nitrogen and low water supply (LN-W), high nitrogen and sufficient water supply (HN+W), and high nitrogen and low water supply (HN-W) after six days of water stress and 24 h of rehydration.
Significance levels are as in Table 1.
Fig 2.
Relationship between photosynthesis (A) and stomatal conductance to the water vapor of amaranth plants grown under low nitrogen and sufficient water supply (LN+W), low nitrogen and low water supply (LN-W), high nitrogen and sufficient water supply (HN+W), and high nitrogen and low water supply (HN-W) after six days of water stress.
The values are the mean±SE of seven plants. The regression equations are red square y = 6.2 + 62.3x, R2 = 0.75; black circle y = −1.3 + 139.7x, R2 = 0.90; blue up-pointing triangle y = 5.9 + 63.7x, R2 = 0.97; pink down-pointing triangle y = −1.6 + 137.2x, R2 = 0.98.
Fig 3.
Stomatal conductance (gs, A), transpiration (E, B), photosynthesis (A, C) and intercellular CO2 concentration (Ci, D) of amaranth plants grown under low nitrogen and sufficient water supply (LN+W), low nitrogen and low water supply (LN-W), high nitrogen and sufficient water supply (HN+W), and high nitrogen and low water supply (HN-W) after 24 h of rehydration.
The values are the mean±SE of seven plants. The means followed by the same small letters (for W at a given N level) and capital letters (for N at a given W supply) are not significantly different at P = 0.05.
Fig 4.
Instantaneous water use efficiency (WUE) of amaranth plants grown under low nitrogen and sufficient water supply (LN+W), low nitrogen and low water supply (LN-W), high nitrogen and sufficient water supply (HN+W), and high nitrogen and low water supply (HN-W) after six days of water stress (A) and 24 h of rehydration (B).
The values are the mean±SE of seven plants. The means followed by the same small letters (for W at a given N level) and capital letters (for N at a given W supply) are not significantly different at P = 0.05.
Fig 5.
The total leaf nitrogen concentration of amaranth plants grown under low nitrogen and sufficient water supply (LN+W), low nitrogen and low water supply (LN-W), high nitrogen and sufficient water supply (HN+W), and high nitrogen and low water supply (HN-W) after six days of water stress (A) and 24 h of rehydration (B).
The alues are the mean±SE of three plants.
Fig 6.
Proline concentration of amaranth plants grown under low nitrogen and sufficient water supply (LN+W), low nitrogen and low water supply (LN-W), high nitrogen and sufficient water supply (HN+W), and high nitrogen and low water supply (HN-W) after six days of water stress (A) and 24 h of rehydration (B).
The values are the mean±SE of four plants. The means followed by the same small letters (for W at a given N level) and capital letters (for N at a given W supply) are not significantly different at P = 0.05.
Fig 7.
Leaf nitrate (A, B) and ammonium (B, C) concentrations of amaranth plants grown under low nitrogen and sufficient water supply (LN+W), low nitrogen and low water supply (LN-W), high nitrogen and sufficient water supply (HN+W), and high nitrogen and low water supply (HN-W) after six days of water stress (A, C) and 24 h of rehydration (B, D).
The values are the mean±SE of three plants. The means followed by the same small letters (for W at a given N level) and capital letters (for N at a given W supply) are not significantly different at P = 0.05.
Table 3.
Content of phenolic acids, flavonoids, and total phenols in μg/mg of 85% MeOH leaf extract, the coefficient of variation, and ANOVA of amaranth plants grown under low nitrogen and sufficient water supply (LN+W), low nitrogen and low water supply (LN-W), high nitrogen and sufficient water supply (HN+W), and high nitrogen and low water supply (HN-W) after six days of water stress (A) and 24 h of rehydration.
Significance levels are as in Table 1.