Using arbuscular mycorrhizal fungi to improve the nutrient quality of crops; nutritional benefits in addition to phosphorus

While arbuscular mycorrhizal (AM) fungi are well known to increase plant phosphorus uptake, there is mounting evidence that AM fungi are important for enhancing the uptake of other minerals. As most crops are capable of forming AM symbioses, these fungi could have the potential to improve the nutritional value of the food we eat. However, we do not yet know which other nutrients are affected by the AM symbiosis, nor whether different AM fungal isolates differ in their ability to acquire nutrients for their hosts. In two separate greenhouse experiments, we tested 5 fungal isolates for their contribution to shoot concentration of 11 macro- and micronutrients in two plants and found that AM fungi influenced nutrient concentrations for all nutrients examined. Allium was highly responsive to AM fungi and showed increased foliar nutrient concentration when nutrients were abundant whereas Plantago did not respond significantly to inoculation from AM fungi. Only plants grown with Glomus intraradices had universally improved nutrient levels. Our study shows that the identity of AM fungi can influence many nutrients besides phosphorus, but the magnitude and direction of this response is also affected by host plant characteristics and soil nutrient status. (c) 2012 Elsevier B.V. All rights reserved.