Table 1.

Effect of exogenous ABA application on growth characteristics of wheat seedlings suffering from PEG-stimulated drought stress for 5 days.

Growth parameters	Treatments	0 day	1 day	2 days	3 days	4 days	5 days
Plant height (cm)	Control	15.06 ± 0.49	16.14 ± 0.54	17.02 ± 0.35	18.41 ± 0.49	19.35 ± 0.49a	22.15 ± 0.55a
	ABA		15.69 ± 0.55	16.34 ± 0.43	17.11 ± 0.39	17.90 ± 0.41b	18.98 ± 0.34b
	PEG		15.32 ± 0.58	15.46 ± 0.44	15.94 ± 0.35	16.16 ± 0.40c	16.71 ± 0.38c
	PEG + ABA		15.54 ± 0.56	16.01 ± 0.51	16.79 ± 0.38	17.09 ± 0.45b	18.61 ± 0.63b
Shoot fresh weight (g·plant−1)	Control	0.161 ± 0.019	0.217 ± 0.016	0.257 ± 0.012	0.262 ± 0.014	0.291 ± 0.014a	0.381 ± 0.014a
	ABA		0.190 ± 0.013	0.217 ± 0.012	0.230 ± 0.014	0.241 ± 0.011b	0.298 ± 0.013b
	PEG		0.175 ± 0.015	0.188 ± 0.018	0.194 ± 0.016	0.212 ± 0.012b	0.234 ± 0.017b
	PEG + ABA		0.184 ± 0.014	0.205 ± 0.013	0.213 ± 0.018	0.224 ± 0.013b	0.285 ± 0.013b
Shoot dry weight (g·plant−1)	Control	0.019 ± 0.002	0.022 ± 0.002	0.025 ± 0.002	0.033 ± 0.001a	0.037 ± 0.001a	0.041 ± 0.001a
	ABA		0.021 ± 0.001	0.023 ± 0.001	0.028 ± 0.001b	0.033 ± 0.001b	0.036 ± 0.000b
	PEG		0.021 ± 0.002	0.022 ± 0.000	0.024 ± 0.002b	0.026 ± 0.001c	0.028 ± 0.001c
	PEG + ABA		0.021 ± 0.001	0.023 ± 0.002	0.027 ± 0.001b	0.032 ± 0.001b	0.034 ± 0.001b
Root fresh weight (g·plant−1)	Control	0.091 ± 0.011	0.098 ± 0.014	0.124 ± 0.010	0.148 ± 0.011a	0.194 ± 0.010a	0.233 ± 0.011a
	ABA		0.094 ± 0.011	0.119 ± 0.011	0.129 ± 0.099b	0.141 ± 0.011b	0.157 ± 0.009b
	PEG		0.093 ± 0.012	0.097 ± 0.011	0.099 ± 0.010b	0.101 ± 0.007c	0.106 ± 0.009c
	PEG + ABA		0.092 ± 0.011	0.112 ± 0.013	0.120 ± 0.107b	0.130 ± 0.012b	0.143 ± 0.010b
Root dry weight (g·plant−1)	Control	0.010 ± 0.001	0.011 ± 0.002	0.015 ± 0.001	0.017 ± 0.000a	0.018 ± 0.000a	0.022 ± 0.001a
	ABA		0.010 ± 0.001	0.011 ± 0.001	0.014 ± 0.000b	0.016 ± 0.000b	0.017 ± 0.000b
	PEG		0.010 ± 0.001	0.011 ± 0.001	0.012 ± 0.000b	0.012 ± 0.000c	0.013 ± 0.000c
	PEG + ABA		0.010 ± 0.002	0.011 ± 0.001	0.013 ± 0.001b	0.015 ± 0.000b	0.016 ± 0.001b

At 0 day of PEG-stimulated drought stress (before stress), the growth parameters of wheat seedlings are same, because PEG or ABA are not immersed in Hoagland's solution at this time point, and sizes and heights of seedlings in all treatments are uniform at this time point. Average values of 10 plants from one dish were considered as one replication and three independent biological replications were performed. Different letters indicate a significant difference at P < 0.05.