Uncovering the impact of AM fungi on wheat nutrient uptake, ion homeostasis, oxidative stress, and antioxidant defense under salinity stress

Abstract

The growth of wheat (Triticum aestivum) is constrained by soil salinity, although some fungal species have been shown to enhance production in saline environments. The yield of grain crops is affected by salt stress, and this study aimed to investigate how arbuscular mycorrhizal fungus (AMF) mitigates salt stress. An experiment was conducted to assess the impact of AMF on wheat growth and yield in conditions of 200 mM salt stress. Wheat seeds were coated with AMF at a rate of 0.1 g (10⁸ spores) during sowing. The results of the experiment demonstrated that AMF inoculation led to a significant improvement in the growth attributes of wheat, including root and shoot length, fresh and dry weight of root and shoot. Furthermore, a significant increase in chlorophyll a, b, total, and carotenoids was observed in the S2 AMF treatment, validating the effectiveness of AMF in enhancing wheat growth under salt stress conditions. Additionally, AMF application reduced the negative effects of salinity stress by increasing the uptake of micronutrients such as Zn, Fe, Cu, and Mn while regulating the uptake of Na (decrease) and K (increase) under salinity stress. In conclusion, this study confirms that AMF is a successful strategy for reducing the negative effects of salt stress on wheat growth and yield. However, further investigations are recommended at the field level under different cereal crops to establish AMF as a more effective amendment for the alleviation of salinity stress in wheat.

Figure 1

Graphical abstract showing the major impacts od treatments on wheat in current study (self generated by using software Biorender).

Figure 2

Effect of arbuscular mycorrhizal fungi (AMF) on shoot length (A), root length (B), shoot fresh weight (C), root fresh weight (D), shoot dry weight (E) and root dry weight (F) in wheat cultivated under normal and saline soil conditions (200 mM NaCl). The data reported are the mean values ± standard error of three independent replicates. Statistical analysis using Fisher's least significant difference (LSD) test showed that significant differences (p < 0.05) existed among the treatment groups. The use of different letters to label the means indicates the presence of significant differences between the groups.

Figure 3

Effect of arbuscular mycorrhizal fungi (AMF) on leaves/plant (A), tillers/plant (B), spikelet’s/plant (C), spike length (D), spike fresh weight (E) and spike dry weight (F) in wheat cultivated under normal and saline soil conditions (200 mM NaCl). The data reported are the mean values ± standard error of three independent replicates. Statistical analysis using Fisher's least significant difference (LSD) test showed that significant differences (p < 0.05) existed among the treatment groups. The use of different letters to label the means indicates the presence of significant differences between the groups.

Figure 4

Effect of arbuscular mycorrhizal fungi (AMF) on contents of chlorophyll a (A), chlorophyll b (B), carotenoids (C), and total chlorophyll (D) in wheat cultivated under normal and saline soil conditions (200 mM NaCl). The data reported are the mean values ± standard error of three independent replicates. Statistical analysis using Fisher's least significant difference (LSD) test showed that significant differences (p < 0.05) existed among the treatment groups. The use of different letters to label the means indicates the presence of significant differences between the groups.

Figure 5

Effect of arbuscular mycorrhizal fungi (AMF) on the concentration of APX (A), SOD (B), CAT (C), and POD (D) in wheat cultivated under normal and saline soil conditions (200 mM NaCl). The data reported are the mean values ± standard error of three independent replicates. Statistical analysis using Fisher's least significant difference (LSD) test showed that significant differences (p < 0.05) existed among the treatment groups. The use of different letters to label the means indicates the presence of significant differences between the groups.

Figure 6

Effect of arbuscular mycorrhizal fungi (AMF) on H₂O₂ (A), MDA (B), electrolyte leakage (C), relative water contents (D), TSS (E) and protein (F) in wheat cultivated under normal and saline soil conditions (200 mM NaCl). The data reported are the mean values ± standard error of three independent replicates. Statistical analysis using Fisher's least significant difference (LSD) test showed that significant differences (p < 0.05) existed among the treatment groups. The use of different letters to label the means indicates the presence of significant differences between the groups.

Figure 7

Effect of arbuscular mycorrhizal fungi (AMF) on Fv/Fm (A), NPQt (B) and Phi-II (C) in wheat cultivated under normal and saline soil conditions (200 mM NaCl). The data reported are the mean values ± standard error of three independent replicates. Statistical analysis using Fisher's least significant difference (LSD) test showed that significant differences (p < 0.05) existed among the treatment groups. The use of different letters to label the means indicates the presence of significant differences between the groups.

Figure 8

Effect of arbuscular mycorrhizal fungi (AMF) on shoot Zn (A), shoot Cu (B) shoot Fe (C) and shoot Mn (D) in wheat cultivated under normal and saline soil conditions (200 mM NaCl). The data reported are the mean values ± standard error of three independent replicates. Statistical analysis using Fisher's least significant difference (LSD) test showed that significant differences (p < 0.05) existed among the treatment groups. The use of different letters to label the means indicates the presence of significant differences between the groups.

Figure 9

Effect of arbuscular mycorrhizal fungi (AMF) on root Zn (A), root Cu (B) root Fe (C) and root Mn (D) in wheat cultivated under normal and saline soil conditions (200 mM NaCl). The data reported are the mean values ± standard error of three independent replicates. Statistical analysis using Fisher's least significant difference (LSD) test showed that significant differences (p < 0.05) existed among the treatment groups. The use of different letters to label the means indicates the presence of significant differences between the groups.

Figure 10

Effect of arbuscular mycorrhizal fungi (AMF) on shoot Na (A), shoot K (B) shoot NO₃ (C) and shoot Cl (D) in wheat cultivated under normal and saline soil conditions (200 mM NaCl). The data reported are the mean values ± standard error of three independent replicates. Statistical analysis using Fisher's least significant difference (LSD) test showed that significant differences (p < 0.05) existed among the treatment groups. The use of different letters to label the means indicates the presence of significant differences between the groups.

Figure 11

Effect of arbuscular mycorrhizal fungi (AMF) on root Na (A), root K (B) root NO₃ (C) and root Cl (D) in wheat cultivated under normal and saline soil conditions (200 mM NaCl). The data reported are the mean values ± standard error of three independent replicates. Statistical analysis using Fisher's least significant difference (LSD) test showed that significant differences (p < 0.05) existed among the treatment groups. The use of different letters to label the means indicates the presence of significant differences between the groups.