Arbuscular Mycorrhiza mediated mineral biofortification and arsenic toxicity mitigation in Triticum aestivum L.

Abstract

The potential of arbuscular mycorrhizal fungi in augmenting arsenic (As) tolerance in wheat is well recognized; however, its effect on mineral profile of grains under As stress is not known. The study was performed to assess the effectiveness of Rhizophagus intraradices on acquisition, translocation, and accumulation of minerals in grains of wheat grown in three As levels (0, 25, and 50 mg As kg−1 soil). Inoculation of R. intraradices decreased As accumulation, increased macronutrients uptake, and ensured higher accumulation of N, P, K, Ca, and Mg in grains. However, its influence was non-significant on S concentration in grains. Presence of As in soil reduced Zn, Ni, and Se and augmented Fe, Na, and Mn concentrations in wheat roots. Conversely, translocation of Fe, Na, and Mn to grains declined significantly and concentrations of Fe, Na, Zn, Mn, Ni, and Se reduced in grains with increasing As level in soil. Regardless of lower concentration of Fe and Mn in roots, mycorrhizal (M)-plants maintained higher concentrations of Zn, Mn, Fe, Ni, Se, and Mo in grains than non-inoculated (NI)-plants. Although, mycorrhizal status of plant had non-significant effect on grain phytic acid concentration, R. intraradices significantly increased the bioavailability of Fe and Zn in grains, which was primarily due to enhanced accumulation of Fe and Zn. While bioavailability of Zn improved from poor to moderate, bioavailability of Fe in M-plants, although higher than NI-plants, remained below the desired level.Overall, the study advocates that in addition to limiting As accumulation in grains, AMF could also provide augmented levels of P, N, K, Mg, Ca, Fe, Zn, Mn, Ni, and Se in grains, thus can aid in overcoming the mineral deficiencies for populations consuming wheat-based diets especially in As contaminated areas.