Arbuscular mycorrhizal fungi species improve the fatty acids profile and nutrients status of soybean cultivars grown under drought stress.

Abstract

To investigate the effects of arbuscular mycorrhizal fungi (AMF) species on the absorption and distribution of mineral nutrients in soybean cultivars under drought stress, an experiment was carried out through a factorial method in the form of randomized complete blocks with six replicates in 2020. Experimental factors include: drought stress at three irrigation levels (well-watered [WW], medium stress [MS] and severe stress [SS], i.e., 100%, 70% and 40% FC), soybean cultivars at two levels (Sepideh and Williams), and mycorrhizae application at four levels (nonapplication, Funneliformis mosseae, Glomus hoi, Rhizophagus intraradices). The results indicated that drought stress increased the concentration of grain potassium (K) and sodium (Na), leaf K, stem and leaf Na, and decreased the concentrations of grain phosphorus (P), copper (Cu), and zinc (Zn), leaf P, stem and leaf Cu, and manganese (Mn). In addition, there was no significant difference in terms of concentrations of grain K. The highest reduction was observed under SS conditions (40% FC). G. hoi colonization increased the concentrations of grain P and Zn, leaf K and Cu and stem Mn under SS conditions (40% FC). In addition, compared to Sepideh cv., Williams cv. showed higher stress resistance. Seed oil content decreased in the plants exposed to drought stress. Severe drought treatments have a deleterious effect on seed fatty acid composition, resulting in enhanced linoleic, oleic and linolenic acids. AMF colonization is a useful tool for improving the plant nutrient uptake, fatty acid profile, efficiency of resource utilization and stabilizing yield, hence reducing the production risks of crops grown under drought stress conditions. It was concluded that AMF colonization should be employed to help alleviate the adverse effects of drought stress. AMF colonization is an effective biotechnological strategy that can alter nutrient uptake and fatty acid composition and enhance oil quality in soybean cultivars under drought conditions.