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 5 Root levels of free fatty acids (FAs) of maize seedlings under drought and arbuscular mycorrhizal fungal inoculation (mean ± SD, n = 5)

Treatment	UFAsⁱ		UFAsⁱⁱ (ng·mg⁻¹ FW)				SFAsⁱⁱ (ng·mg⁻¹ FW)
Treatment	(ng·mg⁻¹ FW)	(%, in the total FAs)	C16.1	C18.1N9	C18.2N6	C18.3N6	C16.0	C18.0	C20.0	C22.0	C24.0
W
NM	193.66 ± 8.64b	30.35 ± 1.01b	0.93 ± 0.26c	57.41 ± 16.13b	109.27 ± 13.76b	14.97 ± 5.52b	329.63 ± 18.14b	47.53 ± 3.98b	9.48 ± 0.66b	7.08 ± 0.84b	36.32 ± 3.14c
AM	462.44 ± 101.61a	39.45 ± 2.24a	46.69 ± 13.51b	119.22 ± 38.44a	253.18 ± 54.89a	26.26 ± 5.04a	585.28 ± 113.65a	44.56 ± 10.19b	7.64 ± 1.14b	7.05 ± 0.40b	43.87 ± 4.60b
D
NM	197.28 ± 11.94b	28.67 ± 1.12c	1.85 ± 0.75c	65.86 ± 6.11b	92.78 ± 9.81b	23.22 ± 7.28ab	344.99 ± 25.28b	57.41 ± 5.22a	11.04 ± 1.78a	10.54 ± 2.01a	49.55 ± 5.03b
AM	447.58 ± 69.30a	37.26 ± 0.60a	67.66 ± 6.23a	124.36 ± 20.17a	224.32 ± 56.72a	20.63 ± 3.45ab	563.12 ± 61.86a	56.01 ± 5.39a	11.87 ± 1.10a	11.58 ± 0.85a	58.38 ± 2.21a
Two-way ANOVA
D	ns	*	ns¹	ns	ns	ns	ns¹	**	**	**	**
I	**	**	**¹	**	**	ns	**¹	ns	ns	ns	**
D × I	ns	ns	–	ns	ns	*	–	ns	ns	ns	ns

Different lowercase letters above the same column 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, UFAs unsaturation fatty acids, SFAs saturation fatty acids, ns not significant
*P < 0.05, **P < 0.01
ⁱPresents all the unsaturation fatty acids that were detected by GS-MS/MS
ⁱⁱPresents the major compositions (with a concentration >10 ng·mg⁻¹ FW) of free FAs
¹ANOVA outputs by nonparametric statistical test