Arbuscular mycorrhiza improved drought tolerance of maize seedlings by altering photosystem II efficiency and the levels of key metabolites

Chemical and Biological Technologies in Agriculture

Table 2 Levels of leaf photosynthesis, sugars, tricarboxylic acids, and fatty acids of maize seedlings under drought and arbuscular mycorrhizal fungal inoculation (mean ± SD, n = 5)

Treatment	Chl (mg·g⁻¹)	PI_abs	DIo/RC	Pn (μmol·m⁻²·s⁻¹)	G_s (mol·m⁻²·s⁻¹)	TS (mg·g⁻¹)	SS (mg·g⁻¹)	OAs (μg·g⁻¹)	FA (nmol·g⁻¹)
W-
NM	0.85 ± 0.06c	0.74 ± 0.15b	0.83 ± 0.07b	22.19 ± 1.68b	0.15 ± 0.02b	26.26 ± 1.80b	10.23 ± 0.75c	1489 ± 160b	13.90 ± 1.59c
AM	1.11 ± 0.11b	1.43 ± 0.39a	0.61 ± 0.09c	28.10 ± 0.96a	0.22 ± 0.03a	27.32 ± 2.20b	12.63 ± 1.56b	822 ± 111c	29.08 ± 5.15a
D
NM	0.89 ± 0.02c	0.63 ± 0.06b	0.95 ± 0.07a	16.19 ± 1.01c	0.09 ± 0.00c	27.92 ± 3.24b	13.50 ± 1.10b	908 ± 94c	14.94 ± 1.53c
AM	1.25 ± 0.12a	1.50 ± 0.28a	0.56 ± 0.05c	10.95 ± 1.30d	0.06 ± 0.01d	32.17 ± 2.58a	23.94 ± 2.07a	2134 ± 281a	20.66 ± 1.93b
Two-way ANOVA
D	**	ns	ns	**	**	*	**	**	ns
I	**	**	**	**	*	*	**	**	**
D × I	ns	ns	*	**	**	ns	**	**	**

Different lowercase letters in the same column indicate statistically significant differences between treatments at P < 0.05 by Duncan’s test
D drought stress, I inoculation treatment, W well-watered, AM arbuscular mycorrhizal fungal inoculation, NM non-mycorrhizal fungal inoculation, Chl chlorophyll, DIo/RC the amount of energy dissipated per active reaction center, FA free fatty acids, g_s stomatal conductance, OAs organic acids in TCA cycle, PI_abs photosystem II performance index on absorption basis, Pn net photosynthetic rate, SS soluble sugars, TS total sugars, ns not significant
*P < 0.05, **P < 0.01