The mycorrhizal pathway of zinc uptake contributes to zinc accumulation in barley and wheat grain

Abstract

Background Increasing zinc (Zn) concentrations in crops is important for alleviation of human Zn deficiency. Arbuscular mycorrhizal fungi (AMF) contribute to plant Zn uptake, but their contribution to Zn in the edible portion of crops has not yet been investigated. This study aimed to quantify the mycorrhizal pathway of Zn uptake into grain of wheat and barley under varying soil Zn availabilities. Bread wheat ( Triticum aestivum ) and barley ( Hordeum vulgare ) were grown in pots with a hyphal compartment containing 65 Zn. Plants were inoculated with Rhizophagus irregularis and grown at three soil Zn concentrations. Radioactive Zn in grain and straw was measured and the contribution of AMF to Zn uptake was calculated. Results The mycorrhizal pathway of Zn uptake contributed up to 24.3% of total above-ground Zn in wheat, and up to 12.7% of that Zn in barley. The greatest contribution by the mycorrhizal pathway was observed in barley at the lowest Zn addition, and in wheat at the highest one. In addition, grain yield of bread wheat was increased by AMF. Conclusions These results suggest that AMF have a substantial role in uptake of Zn into cereals, and the proportional contribution by the MPU is dependent on plant species, as well as available soil Zn. Electronic supplementary material The online version of this article (10.1186/s12870-019-1741-y) contains supplementary material, which is available to authorized users.

Field Inoculation of Bread Wheat with Rhizophagus irregularis under Organic Farming: Variability in Growth Response and Nutritional Uptake of Eleven Old Genotypes and A Modern Variety

“…Conversely, in an experiment of field inoculation with the same AMF isolate, at early crop stages, Ercoli et al [21] did not find any difference in Fe and Zn concentration in shoots and roots of durum wheat. This can be explained by multiple factors, such as soil Zn deficiency found in the present study, differential response of wheat species/varieties and a large compatibilty at early stages of bread wheat with the inoculated AMF isolate [22].…”

“…The AM symbiosis is known for improving plant access to mineral nutrients, through the development of an extraradical mycelium, consisting of a complex and extensive network of hyphae spreading into the soil [71]. The active role of AMF in the uptake and transport of minerals needed for plant growth has been demonstrated in various plant/AMF isolate combinations (e.g., P [72,73]; N [74,75]; Zn [22,76]; Fe, Cu, Mn [19]. The effectiveness of the AM symbiosis for plant nutrient uptake was studied in bread wheat (Triticum aestivum L.) [77][78][79] and durum wheat (Triticum durum Desf.)…”

“…Modern and old varieties responded distinctly to AMF inoculation, and the modern variety showed higher responsiveness in terms of root length, AMF root colonization and grain macro-and micro-nutrient contents. The mycorrhizal pathway of Zn uptake was recently quantified in a pot experiment, accounting for 24.3% and 12.7% of the total aboveground Zn content in bread wheat and barley, respectively [22].…”

Identification of a unique ZIP transporter involved in zinc uptake via the arbuscular mycorrhizal fungal pathway

“…Managed effectively, AM fungi provide a tool for improved crop Zn nutrition in the field, particularly on Zn-deficient soils (16). Radioisotope tracing studies have demonstrated that the AM fungus Rhizophagus irregularis can contribute as much as 25% of shoot Zn uptake in tomato plants, 24% of grain Zn in wheat, and 12% in barley (17,18).…”

Interaction Between Conservation Tillage and Nitrogen Fertilization Shapes Prokaryotic and Fungal Diversity at Different Soil Depths: Evidence From a 23-Year Field Experiment in the Mediterranean Area

“…Minimum soil disturbance could also allow suitable conditions for the promotion of the abundance and diversity of symbiotic fungi, such as arbuscular mycorrhizal fungi (AMF), as well as shifts of their community structures (Alguacil et al, 2008; Brito et al, 2012). Arbuscular mycorrhizal fungi can improve soil aggregation and structure on one side, and enhance plant growth, crop production, plant nutrient status and health on the other side (Ercoli et al, 2017; Caruso, 2018; Powell and Rillig, 2018; Zhang et al, 2018; Coccina et al, 2019). However, according to a recent meta-analysis, the response of soil microbial diversity to tillage is highly variable depending on climatic conditions and soil properties (de Graaff et al, 2019).…”