Cadmium is a heavy metal (HM) that inhibits plant growth and leads to death, causing great losses in yields, especially in Cd hyperaccumulator crops such as Glycine max (L.) Merr. (soybean), a worldwide economically important legume. Furthermore, Cd incorporation into the food chain is a health hazard. Oxidative stress (OS) is a plant response to abiotic and biotic stresses with an intracellular burst of reactive oxygen species (ROS) that causes damage to lipids, proteins, and DNA. The arbuscular mycorrhizal fungal (AMF) association is a plant strategy to cope with HM and to alleviate OS. Our aim was to evaluate the mitigation effects of mycorrhization with AMF Rhizophagus intraradices on soybean growth, nutrients, Cd accumulation, lipid peroxidation, and the activity of different antioxidant agents under Cd (0.7–1.2 mg kg⁻¹ bioavailable Cd) induced OS. Our results suggest that glutathione may act as a signal molecule in a defense response to Cd-induced OS, and mycorrhization may avoid Cd-induced growth inhibition and reduce Cd accumulation in roots. It is discussed that R. intraradices mycorrhization would act as a signal, promoting the generation of a soybean cross tolerance response to Cd pollution, therefore evidencing the potential of this AMF association for bioremediation and encouragement of crop development, particularly because it is an interaction between a worldwide cultivated Cd hyperaccumulator plant and an AMF–HM–accumulator commonly present in soils.

The relationships of altitude, host life cycle (annual or perennial) and photosynthetic pathway (C3 or C4) with arbuscular mycorrhiza (AM) root coloni

The Andean Puna is an arid, high-elevation plateau in which plants such as grasses experience high abiotic stress and distinctive environmental conditions. We assessed colonization by arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) in the roots of 20 native grass species and examined the relationship between root-associated fungi (AMF and DSE) as a function of the elevation of study sites, the photosynthetic pathways of the grass hosts, and the hosts’ life cycles. In general, grasses were co-colonized by AMF and DSE and the colonization by AMF and DSE was not extensive. The extension of colonization of AMF and that of DSE were positively correlated, as were number of arbuscules and DSE colonization extension. The extension of AMF colonization differed among sites with different elevations, but DSE colonization was similar across sites. Overall, AMF and DSE patterns shifted as a function of elevation in most grass species, with no general trends observed with respect to host photosynthetic pathway or life cycle. In general, our observations differ from previous studies in the Northern Hemisphere. Variation among sites in AMF and DSE colonization was greater than variation that could be explained by the other factors considered here, suggesting a strong influence of environmental factors. We predict that both AMF and DSE may have established synergistic and beneficial associations with grasses in these distinctive and harsh ecosystems.

Mycorrhizal fungus diversity is an ecosystem health indicator, and thus, the appreciation of the aboveground as well as the belowground biota, such as fungi associated with natural and managed ecosystems, is essential to provide sustainable products and suggestions to farmers. Less is known about the totally arbuscular mycorrhizal fungi (AMF) and fungal endophytes useful to agroecology, which are environment friendly microbial biofertilizers to mitigate the complications of conventional farming. Specific AMF are found in most covers; grassy ecosystems are increasingly investigated through their exclusive fungal species that improve sustainable cultivation. Different grazed pastures, forages, and their diversity are important objects of study either in economic or ecological scope. Based on recent reports, the occurrence of AMF in grasslands and pastures is significant, supporting more diverse AMF than native forests. Therefore, we show current information on these topics. We conducted a Web of Science search of published articles on AMF, pastures, and grasslands and analyzed them. The results confirmed the important role of pH as the driver of AMF diversity distribution between the grassy ecosystems from Argentina and Brazil. In grasslands, the main family represented was Glomeraceae, while pastures maintain predominantly Acaulosporaceae. Brazilian grasslands and pastures presented four times the AMF richness of those from Argentina.