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 4 Root levels of P and C, sugars, and tricarboxylic acids of maize seedlings under drought and arbuscular mycorrhizal fungal inoculation (mean ± SD, n = 5)

Treatment	P (mg·g⁻¹)	C (%)	R:S C ratio	SS:TS	Gly (mg·g⁻¹)	OAs (μg·g⁻¹)
W
NM	2.42 ± 0.53b	41.22 ± 0.78a	0.40 ± 0.07b	0.33 ± 0.02b	4.95 ± 0.70b	311 ± 63a
AM	3.80 ± 0.28a	41.34 ± 0.81a	0.17 ± 0.01d	0.40 ± 0.02b	3.62 ± 0.21c	281 ± 44a
D
NM	2.49 ± 0.13b	40.72 ± 0.93a	0.56 ± 0.10a	0.41 ± 0.06b	8.11 ± 0.89a	254 ± 50a
AM	3.26 ± 0.45a	40.18 ± 1.43a	0.30 ± 0.03c	0.53 ± 0.11a	5.72 ± 0.48b	289 ± 31a
Two-way ANOVA
D	ns	ns	**	**	**	ns
I	**	ns	**	*	**	ns
D × I	ns	ns	ns	ns	ns	ns

Different letters above the columns indicate statistically significant differences between means 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, Gly glycogen, OAs organic acids in the tricarboxylic acid cycle, SS soluble sugars, TS total sugars