Cotton (Gossypium hirsutum L.) is a promising candidate for an Arsenic (As)-tolerant plant due to its low As accumulation in fibers. The individual arbuscular mycorrhizal fungi (AMF) inoculation or exogenous calcium (Ca²⁺) application is known to enhance heavy metal tolerance in higher plants; however, their synergistic mechanisms in alleviating As stress in cotton remain poorly understood. A three-factor pot experiment was conducted, including two levels of AMF (Funneliformis mosseae C.Walker & A.Schüßler) inoculation (non-inoculated/inoculated), As stress (0/100 mgAs⁵⁺·kg⁻¹soil), and exogenous Ca²⁺ (CaCl₂) application (0/20 mmol·L⁻¹ CaCl₂). AMF inoculation and Ca²⁺ application were investigated for their effects on cotton growth, root morphology, photosynthetic characteristics, osmotic regulators, antioxidant enzyme activities, and ion homeostasis under As stress. Results showed As stress significantly disrupted cotton growth (decreased plant height, shoot and root dry weight) and root morphology (reduced total root length, root area, and root fork number), photosynthetic capacity (reduced Pn, Ci, Fv/Fm, and ΦPSII), osmotic adjustment (decreased proline, soluble sugar and protein), antioxidant defense (inhibited SOD, POD, CAT activities), and K⁺/Ca²⁺ homeostasis (reduced concentration of K⁺ and Ca²⁺, and K⁺/Ca²⁺ ratio). Both AMF inoculation and Ca²⁺ application independently alleviated these adverse effects of As stress. At the same time, AMF symbiosis combined with exogenous Ca²⁺ was better than AMF inoculation or Ca²⁺ application alone in optimizing root architecture, improving stomatal function and photosynthetic efficiency, enhancing osmotic regulator accumulation and antioxidant enzyme activities, and restoring ion balance under As stress. Three-way ANOVA confirmed significant As×AMF×Ca²⁺ interactions on key parameters such as Pn and ΦPSII. In summary, both AMF inoculation and Ca²⁺ application synergistically enhanced cotton As tolerance through regulating growth, root morphology, photosynthetic characteristics, osmotic regulators, antioxidant enzyme activities, and ion homeostasis, demonstrating its potential for sustainable cotton cultivation in As-contaminated soils.

Cadmium (Cd) pollution threatens global ecosystems and human health owing to its high toxicity, long-term persistence, and dual irreversibility of environmental geochemical behavior and biological toxicological effects. The interaction between phosphate-solubilizing fungi (PSF) and clay minerals governs the biogeochemical transformation, chemical speciation, and migration fate of soil Cd. However, the dose-dependent mechanisms underlying Cd²⁺ removal by Aspergillus niger (A. niger) and montmorillonite remain unclear. In this study, three Cd²⁺ stress levels were simulated, and four A. niger-montmorillonite composite systems were established. Key physicochemical and metabolic indicators, including pH, available phosphorus (AP) concentration, oxalic acid concentration, acid phosphatase (ACP) activity, and Cd²⁺ removal rate, were determined. The results showed that the single A. niger treatment achieved the optimal Cd removal performance among all composite treatment groups. Severe Cd²⁺ stress induced abundant oxalic acid and ACP secretion, which simultaneously mobilized phosphorus and facilitated Cd removal via phosphate precipitation and oxalate complexation. Low-to-medium montmorillonite dosage temporarily alleviated Cd²⁺ toxicity, whereas high montmorillonite dosage restricted fungal metabolic exudates and, together with acid-mediated mineral-Cd interactions, triggered antagonistic rather than synergistic Cd removal. This study clarifies how montmorillonite dosage reshapes the metabolic defense of A. niger, providing theoretical references for optimizing microbe–montmorillonite composite remediation formulations.

Wetland restoration has become increasingly important for biodiversity conservation, ecosystem-function recovery, and climate resilience. However, global restoration evidence remains fragmented across geographical regions, wetland systems, restoration approaches, and ecological response domains, limiting the identification of broadly transferable restoration principles. This review conducted a systematic mapping review of global wetland ecological restoration research published between 2000 and 2024 by integrating evidence mapping, bibliometric analysis, and ecological interpretation of representative restoration studies. The global literature expanded substantially during the study period, but the evidence base remained unevenly distributed among regions, institutions, and wetland contexts. Differences among research participation, research leadership, and study locations indicated that patterns of scientific output were shaped not only by wetland distribution and restoration needs but also by research capacity, monitoring infrastructure, and institutional networks. Thematic development revealed a transition from intervention-oriented studies focusing on hydrological modification, habitat reconstruction, and pollution control toward broader consideration of biodiversity recovery, ecosystem functions, carbon dynamics, microbial processes, and nature-based solutions. Across wetland systems, restoration pathways varied according to ecological processes and degradation contexts, but common challenges emerged regarding the translation of structural improvements into durable ecological recovery. Improvements in habitat structure, vegetation, hydrological conditions, or physicochemical indicators did not necessarily indicate equivalent recovery of biodiversity, ecosystem functions, or resilience. These findings highlight the need for long-term, multidimensional restoration assessment, stronger evidence generation in underrepresented regions, and adaptive approaches that integrate ecological processes, monitoring, and local contexts to support durable wetland recovery.