Figure 1.
Responses of drought tolerant and sensitive varieties of soybean towards short-term water stress.
(a–d) trifoliate leaves and (e–h) nodules. (a, e) dry weight (DW); (b) relative water content (RWC), (f) nitrogenase activity, (c, g) ureide levels and (d, h) proline levels in 17-day-old plants subjected to 10 days water sufficient and deficient conditions. TC: Tolerant genotype Control; TD: Tolerant subjected to Drought, SC: Sensitive genotype Control; SD: Sensitive subjected to Drought. Data represent the mean ± standard deviation (SD) of five to 15 replicates. Different letters at the top of each bar indicate significant differences at P<0.01.
Figure 2.
1H NMR spectra of (a) leaves and (b) nodules of water-soluble extracts from well-watered tolerant soybean plants.
Assignments: 1, alanine; 2, GABA; 3, glutamine; 4, malic acid; 5, succinic acid; 6, citric acid; 7, aspartate; 8, asparagine; 9, myo-inositol; 10, choline; 11, pinitol; 12, sucrose; 13, fumaric acid; 14, trigonelline. HDO: deuterated water.
Table 1.
List of variables used in statistical analysis for leaves and nodules samples.
Figure 3.
Schematic representation of the selected metabolic pathways affected by drought in two soybean genotypes contrasting in sensitivity/tolerance to water stress.
Histograms represent relative changes in the level of the metabolites (arbitrary units) in trifoliate leaves and nodules in the plants subjected to water stress. Values are presented as the mean ± standard deviation (SD) of nine independent biological determinations. TC: Tolerant control; TD: Tolerant Drought, SC: Sensitive Control; SD: Sensitive Drought.
Table 2.
Two factors ANOVA with a 2×2 between groups design (drought tolerant vs. sensitive plants, well-watered vs. drought stressed plants), leaves samples.
Table 3.
ANOVA on single groups, two types of grouping (control vs stressed, and tollerant vs sensitive) leave samples.
Table 4.
Two factors ANOVA with a 2×2 between groups design (drought tolerant vs. sensitive plants, well-watered vs. drought stressed plants), nodules samples.
Figure 4.
Principal component analysis (PCA) of 15 metabolites in the leaves from the plants grown under water sufficient and deficient conditions.
Score (a) and loading plot (b) of soybean leaf samples. LTC: Leaf Tolerant Control, LTD: Leaf Tolerant Drought, LSC: Leaf Sensitive Control, LSD: Leaf Sensitive Drought.
Figure 5.
Principal component analysis (PCA) of 15 metabolites in nodules from the plants subjected to water sufficient and deficient conditions.
Score (a) and loading plot (b) of soybean nodule samples. NTC: Nodule Tolerant Control, NTD: Nodule Tolerant Drought, NSC: Nodule Sensitive Control, NSD: Nodule Sensitive Drought.