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Expression patterns of R. irregularis SMF genes. (a) RiSMFs expression, based on RNAseq analyses of ERM grown in monoxenic cultures as well as IRM and arbucules (ARB) collected by laser microdissection, from Medicago truncatula mycorrhizal roots. Error bars represent SE from three biological replicates. Different letters indicate significant differences (p < 0.05). (b) Heatmap showing the hierarchical clustering of SMF genes, grouped according to the expression patterns in ERM, IRM and ARB. Gradient color ranging from white to bright blue corresponds to expression values log2 transformed.
Source publication
Transporters of the NRAMP family are ubiquitous metal-transition transporters, playing a key role in metal homeostasis, especially in Mn and Fe homeostasis. In this work, we report the characterization of the NRAMP family members (RiSMF1, RiSMF2, RiSMF3.1 and RiSMF3.2) of the arbuscular mycorrhizal (AM) fungus Rhizophagus irregularis. Phylogenetic...
Context in source publication
Context 1
... try to understand the biological function of the RiSMFs, their expression levels in various fungal structures were investigated, by using recent RNA-Seq data retrieved from ERM grown in monoxenic cultures, laser-microdissected Medicago truncatula cortical cells containing arbuscules and laser-microdissected M. truncatula root cells containing IRM [33,34]. The four R. irregularis SMF genes were expressed in all fungal structures (Figure 4). RiSMF2 was highly expressed in the IRM and in the arbuscules. ...
Citations
... In addition, they have been reported in the expression of other iron reductase groups (permeases) and ferroxidases such as NRAMP, RISMF1, RISMF2, RISMF3.1, RISMF3.2 [40,41], SbDMAS2, SbNAS2 and SbYS1 [42]. As well as ZmNAS1, ZmNAS3 and ZmYS1, which are involved in the solubility and absorption of Zn/Fe in plants [43]. ...
Arbuscular mycorrhizal fungi (AMF) play an important role in the nutritional dynamics of plants. Influencing the extraction, translocation and distribution of minerals from the soil to the plant. This has a positive effect on the mineral and nutritional content of agricultural crops. Therefore, HMA is considered a sustainable alternative, reducing the use of fertilizers by up to 50–70%. It should also be taken into account as a microbial soil resource that can contribute to self-sufficiency, food security and sovereignty in marginalized soils and areas vulnerable to population malnutrition. This chapter mentions relevant studies in relation to mycorrhizal interaction with the quality of plant foods. Recent findings have reported an increase in zinc and iron content in basic grains. Some alternative crops such as fruit, vegetables and edible foliage, have increased their phytochemical content (organic acids, phenols, carotenoids, etc.) and post-harvest properties such as texture, colorimetry and sugar content. This directly influences the taste, smell and palatability of food. In conclusion, AMF is considered a strategy to optimize and transform agro-food systems, oriented toward nutritional and sensory enrichment of plant tissues that can be used for human consumption.
... PMR1 of the plant pathogen Magnaporthe oryzae is essential for morphogenesis [54], and mutants of pmr1 and gdt1 in F. graminearum and A. flavus likewise show defects in morphology that are rescued by high Mn supplementation [48••, 49•]. Even Mn in the growth media can impact the morphology of wild-type fungi, as has been reported with filamentation of Rhizophagus irregularis [55] and biofilm formation in Candida parapsilosis [56]. ...
Purpose of Review
Copper, zinc, iron, and manganese are essential micronutrients for all living organisms. Microbial pathogens must acquire these elements from their host. Through a process termed nutritional immunity, animal hosts seek to withhold these vital nutrients from the microbe and the competition for metals can influence survival outcomes during infection. Much is known about the battle for iron, copper, and zinc during fungal infections, but a picture is just now beginning to emerge for manganese.
Recent Findings
Pathogenic fungi utilize manganese for antioxidant defense, cell wall construction, morphogenesis, and survival in animal and plant hosts. The animal host can limit manganese availability for invading fungi at the macrophage, neutrophil, and whole tissue levels.
Summary
Here, we review the role of manganese as an essential nutrient for pathogenic fungi and the ways an animal host can withhold this vital metal from infectious fungi of clinical and agricultural importance.
... Additionally, the inclusion of B-nSi-nFe led to the downregulation of Cd transport-related genes (ZmNramp5, ZmHMA2 and ZmHMA3), indicating substantial Cd immobilization and decreased Cd uptake in maize (Fig. 7). Nramp5 proteins govern Cd uptake in plants, their varying expression and transport abilities in rice, wheat, and maize are due to differing transmembrane residues (López-Lorca et al., 2022;Sui et al., 2018). HMA2, a plasma membrane transporter, uses ATP hydrolysis to actively move Cd from roots to shoots (Meraklı and Memon, 2023). ...
... Kabir et al. [40] also found that AMF upregulate another ferric reductase gene, HaFRO1, alongside the expression of transport genes HaNramp1 and HaIRT1. Moreover, in the context of iron homeostasis, natural resistance-associated macrophage protein transporters also play a key role, and members, such as RiSMF1, RiSMF2, RiSMF3.1, and RiSMF3.2, have been identified in R. irregularis [20,44]. ...
Arbuscular mycorrhizal fungi (AMF) form a vital symbiotic relationship with plants. Through their extensive hyphal networks, AMF extend the absorptive capacity of plant roots, thereby allowing plants to reach otherwise inaccessible micronutrient sources. Iron, a critical micronutrient involved in photosynthesis and other metabolic processes, often becomes inaccessible owing to its tendency to form insoluble complexes in soil. AMF symbiosis significantly ameliorates this challenge by enhancing iron uptake and homeostasis in plants, altering root architecture, and producing root exudates that improve iron solubility. Moreover, the interaction with diverse soil bacteria, particularly plant growth-promoting rhizobacteria, can potentiate the benefits of AMF symbiosis. Siderophores are low-molecular-weight chelators with iron-binding capacities produced by various microorganisms and plant roots. They play pivotal roles in regulating intracellular iron and have been identified in different mycorrhizal associations, including AMF. While molecular mechanisms behind AMF-mediated iron uptake have been partially explored, the intricate networks involving AMF, plants, siderophores, and other soil microbiota are largely unknown. This review focuses on the multifaceted roles of AMF in plant–iron homeostasis, interactions with soil bacteria, and the potential of siderophores in these processes, emphasizing the possibilities for harnessing these relationships for sustainable agriculture and enhancing plant productivity.
... The genes encoding NRAMP family members RiSMF1, RiSMF2, RiSMF3.1 and RiSMF3.2 were characterized in Rhizophagus irregularis. In the complementary experiment of yeast fet3fet4 mutant, only RiSMF3.2 was proved to be an iron transporter [83]. ...
Iron is an essential element for most organisms. Both plants and microorganisms have developed different mechanisms for iron uptake, transport and storage. In the symbiosis systems, such as rhizobia–legume symbiosis and arbuscular mycorrhizal (AM) symbiosis, maintaining iron homeostasis to meet the requirements for the interaction between the host plants and the symbiotic microbes is a new challenge. This intriguing topic has drawn the attention of many botanists and microbiologists, and many discoveries have been achieved so far. In this review, we discuss the current progress on iron uptake and transport in the nodules and iron homeostasis in rhizobia–legume symbiosis. The discoveries with regard to iron uptake in AM fungi, iron uptake regulation in AM plants and interactions between iron and other nutrient elements during AM symbiosis are also summarized. At the end of this review, we propose prospects for future studies in this fascinating research area.
The copper transport (COPT/Ctr) family plays an important role in maintaining metal homeostasis in organisms, and many species rely on Ctrs to achieve transmembrane transport via copper (Cu) uptake. At present, the Ctr family is widely studied in plants. However, there are few reports on the use of Ctrs in edible mushrooms. In this study, the Pleurotus ostreatus CCMSSC00389 strain was used as the research object, and the addition of exogenous copper ions (Cu2+) increased the temperature tolerance of mycelia, maintained the integrity of cell membranes, and increased mycelial density. In addition, four PoCtr genes were further identified and subjected to bioinformatics analysis. Further research revealed that there were differences in the expression patterns of the PoCtr genes under different temperature stresses. In addition, the biological function of PoCtr4 was further explored by constructing transformed strains. The results showed that OE-PoCtr4 enhanced the tolerance of mycelia to heat stress and H2O2. After applying heat stress (40 °C), OE-PoCtr4 promoted the recovery of mycelia. Under mild stress (32 °C), OE-PoCtr4 promoted mycelial growth, maintained cell membrane integrity, and reduced the degree of cell membrane damage caused by heat stress. It is speculated that OE-PoCtr4 may maintain the integrity of the cell membrane and enhance the heat resistance of mycelia by regulating the homeostasis of Cu2+.
The role of brassinosteroids (BRs) in enabling plants to respond effectively to adverse conditions is well known, though the precise mechanism of action that helps plants cope with arsenic (As) toxicity is still difficult to interpret. Therefore we tested the effect of brassinolide (BL) spray (0, 0.5, and 1 mg · L-1) on As (0, and 10 mg · L-1 ) stressed tomato defense responses As stress led to the induction of oxidative stress, impaired chlorophyll and nitrogen metabolism, and Fe uptake, in conjunction with a reduction in plant growth and biomass. BL spray, on the contrary,protected the photosynthetic system and helped plants grow better under As stress. This was achieved by controlling the metabolism of chlorophyll and proline and lowering the amounts of methylglyoxal and H2O2 through glyoxalase I and II and antioxidant enzymes. BL decreased arsenic accumulation by directing As sequestration towards vacuoles and increased Fe amount in the leaves and roots by regulating the expression of As (Lsi1 and Lsi2) and Fe (IRT1, IRT2,NRAMP1, and NRAMP3) transporters in As-stressed tomatoes. Furthermore, BL boosted adaptability against As phytotoxicity, while reducing the damaging impacts on photosynthesis,nitrogen metabolism, sulfur asimilation, and Fe absorption. These results offer a solid framework for the development of exogenous BRs-based breeding strategies for safer agricultural development.
In the last years, heavy metal (HM) pollution has spread across natural and anthropic ecosystems posing inevitable, serious health risks. Commitments to resolve this issue resulted in tightening regulations and calls to action. The use of plants and their symbionts for remediation enjoys support. Nonetheless, keystones between mycorrhizal research and their application have still to be identified. The aim of this work was to provide an updated outlook on the current HM remediation contexts, with particular focus on the relevance of arbuscular mycorrhizal (AM) symbiosis as part of the plant-soil system. The AM potential implication in enhancing plant survival and performance in presence of HM stress could translate into efficient mitigation of environmental and health risks associated with increasing contamination of natural and human-managed ecosystems. Dust lift-up and leaching of HMs are the main routes of exposure and spread of pollution. The plant-soil system can reduce these risks. Moreover, the plants growing on HM-contaminated lands display decreased chlorophyll level as common toxicity symptom. Therefore, changes occurring in the chlorophyll content and/or in chlorophyll-associated parameters can be used as indicators revealing plant survival and physiological performance in phytoremediation contexts. Available scientific information suggests that plant inoculation with arbuscular mycorrhizal fungi (AMF) increases chlorophyll levels in most cases. Such response most likely occurs as the burden of HM stress is sustained by the symbiotic partners together, so that each partner has a role in mitigating the HM negative effects. Contaminated agricultural land and urban land come with their particular challenges. Feasibility in decontaminating them strictly relies on the achievement of long-term desired outcomes. Hence, perennial energy crops that establish successful AM symbiosis represent the best candidate plant species for further research on phytoremediation approaches. Plant Stress 12 (2024) 100439