Molecular and biochemical mechanisms associated with differential responses to drought tolerance in wheat (Triticum aestivum L.)

Figures & data

Figure 1. Morphological view of BG-25 and Bijoy grown under PEG– and PEG+ hydroponic conditions.

Figure 2. Chlorophyll concentrations (a and b) in leaves of BG-25 and Nijoy grown in PEG– and PEG+ hydroponic culture. Values are the means of three independent replications with standard deviations. Different letters indicate significant differences between means±SD of treatments (n = 3). Leaves were harvested from 2-week old plants.

Table 1. Morphological features of BG-25 and Bijoy grown in the absence and presence of PEG under hydroponic conditions.

	BG-25		Bijoy
Features	PEG–	PEG+	PEG–	PEG+
Shoot height (cm)	22.3 ± 0.56^a	21.15 ± 0.77^a	22.4 ± 2.15^a	16.4 ± 1.35^b
Shoot dry weight (g)	0.16 ± 0.03^a	0.16 ± 0.004^a	0.12 ± 0.05^a	0.062 ± 0.015^b
Root length (cm)	7.7 ± 0.70^a	6.4 ± 0.28^a	12.13 ± 0.93^a	7.9 ± 0.26^b
Root dry weight (g)	0.016 ± 0.003^a	0.01 ± 0.006^a	0.013 ± 0.003^a	0.0065 ± 0.002^b

Note: Different letters indicate significant differences between means ± SD of treatments (n = 3). Data were taken on 2-week old plants.

Figure 3. Expression analysis of Actin (control), TaCRT1 and DREB1A transcripts in roots of BG-25 and Bijoy grown under PEG– and PEG+ hydroponic conditions. Roots were harvested from 2-week old plants.

Table 2. Activities of different antioxidant enzymes in roots of BG-25 and Bijoy grown in the absence and presence of PEG under hydroponic conditions.

	BG-25			Bijoy
Enzyme activities	PEG–	PEG+	Fold (ratio)	PEG–	PEG+	Fold (ratio)
CAT min^−1 [(mg protein)^−1]	1.52 ± 0.093^a	2.17 ± 0.044^b	1.43-fold increase	0.89 ± 0.140^a	1.12 ± 0.204^a	1.26-fold increase
POD min^−1 [(mg protein)^−1]	0.22 ± 0.040^a	2.16 ± 0.250^b	9.48-fold increase	0.20 ± 0.040^a	0.16 ± 0.017^a	1.23-fold decrease
GR [nmol.NADH.min^−1 mg protein^−1]	0.033 ± 0.004^a	0.058 ± 0.008^b	1.76-fold increase	0.072 ± 0.016^a	0.122 ± 0.031^a	1.68-fold increase
SOD [U.mg^–1 protein ]	4.38 ± 0.462^a	5.31 ± 0.088^a	1.21-fold increase	8.64 ± 0.370^a	7.93 ± 0.972^a	108-fold decrease
MDA content (nmol g^−1 FW)	1.87 ± 0.045^a	0.79 ± 0.124^b	2.36-fold decrease	1.70 ± 0.074^a	2.08 ± 0.130^a	1.22-fold increase

Note: Different letters indicate significant differences between means ± SD of treatments (n = 3). Data were taken on 2-week old plants.

Table 3. HPLC analysis of amino acids (µg/mg) in roots of BG-25 and Bijoy grown under PEG– and PEG+ hydroponic conditions.

	BG-25			Bijoy
Metabolites	PEG–	PEG+	Fold (ratio)	PEG–	PEG+	Fold (ratio)
Glutathione	5.91 ± 0.53^a	8.80 ± 1.10^b	1.48-fold increase	2.19 ± 0.14^a	2.33 ± 0.07^a	1.06-fold increase
Cysteine	2.77 ± 0.25^a	3.36 ± 0.42^b	1.21-fold increase	ND	ND	NA
Methionine	5.95 ± 0.53^a	7.28 ± 0.91^b	1.22-fold increase	6.19 ± 0.41^a	1.16 ± 0.03^b	5.31-fold decrease
Glycine	4.21 ± 0.38^a	4.43 ± 0.55^a	1.05-fold increase	ND	ND	NA
Proline	5.38 ± 0.48^a	6.74 ± 0.84^b	1.25-fold increase	9.68 ± 0.65^a	2.95 ± 0.09^b	3.27-fold decrease
Leucine	ND	6.27 ± 0.78^b	NA	1.91 ± 0.12^a	1.33 ± 0.04^a	1.43-fold decrease

Note: Different letters indicate significant differences between means ± SD of treatments (n = 3). Roots were harvested from 2-week old plants.

ND, not detected; NA, not applicable.