Although arbuscular mycorrhizal fungi (AMF) have been assumed to facilitate soil organic carbon (SOC) sequestration, they also regulate SOC decomposition via specific interactions with saprotrophs. We tested AMF hyphal impacts on SOC dynamics (e.g. labile C vs persistent C) under monoculture conditions with different grasses (e.g. Leymus chinensis and Stipa grandis) using an in-growth core method. Although the total SOC pool was unaffected by the presence of AM fungal hyphae, the proportional composition of labile and persistent C within SOC pools differed significantly between treatments with and without hyphal access. The presence of AM fungal hyphae from L. chinensis was associated with increased abundances of actinomycetes and Gram-positive bacteria, alongside the higher activity of polyphenol oxidase that breaks down persistent soil C, leading to a higher proportion of labile C in the SOC pool. Under S. grandis, however, hyphal presence corresponded with a greater abundance of Gram-negative bacteria that often can degrade labile soil C, resulting in a higher proportion of persistent C in the SOC pool. The influence of AM fungal hyphae on SOC depends on the identity of host plants and thus shifts in plant community composition may strongly alter SOC dynamics in grasslands.

Grasses, including major cereal crops, associate with arbuscular mycorrhizal (AM) fungi to varying degrees depending on environmental conditions. Understanding mechanisms driving this environment-induced variation in mycorrhization, i.e. plant AM plasticity, is necessary to predict grass-mycorrhizal responses to global change factors, such as nutrient enrichment, and to resolve the role of AM symbiosis in cereal crop production. We compared AM plasticity in four cereal crops by testing the effect of nitrogen (N) fertilization on AM colonization and root PLFA 16:1ω5 concentration. To assess whether mycorrhization patterns reflect root functional traits, we compared specific root length among species. To determine whether plants regulate AM colonization qualitatively (by selectively associating with certain AM taxa) or quantitatively (by collectively suppressing colonization across taxa), we investigated directional shifts and variability in AM community structure in response to N fertilization. AM colonization varied between cereal species and was reduced by N fertilization, but we found limited evidence for interspecific differences in AM plasticity. Winter wheat appeared less AM responsive and associated more with uncultured AM fungi compared to the three spring-sown cereal species, oat, spring wheat and spring barley. Fertilization did not affect AM community composition, and within-species variation in AM community β-dispersion did not covary with variation in AM colonization or PLFA 16:1ω5 concentration. These results support the view that host plants regulate arbuscular mycorrhization quantitatively rather than through taxonomic selectivity. We propose AM plasticity as a plant-mycorrhizal trait to be used for more accurate predictions of plant environmental responses in eco-physiological and agroecological research.

Brassicaceae cover crops are widely adopted in agroecosystems, yet their legacy effects on arbuscular mycorrhizal fungi (AMF) remain context-dependent and mechanistically unresolved. In this study, we assessed how a standing white mustard (Sinapis alba L.) cover crop interacts with tillage intensity to influence AMF colonization, community composition, diversity, and abundance in volunteer barley (Hordeum vulgare L.) roots. AMF responses were quantified using complementary approaches, including microscopic assessment of root colonization, 18S rRNA gene amplicon sequencing, and taxon-specific real-time PCR (qPCR). Roots were sampled before white mustard termination, thereby avoiding tissue disruption and isothiocyanate release, to distinguish host-mediated filtering from biofumigation-associated chemical disturbance. Colonization intensity was primarily determined by tillage, with significantly higher colonization under no-tillage compared to conventional tillage. Community-level responses, however, were dependent on taxonomic resolution. At the amplicon sequence variant (ASV) level, white mustard reduced AMF richness, whereas diversity and evenness were unaffected. At the genus level, richness remained stable, but diversity and evenness declined under the combined effects of cover cropping and conventional tillage, indicating that tillage modulated the impact of cover crop legacy. Dominant Glomeraceae lineages remained stable across treatments, and total AMF abundance showed no consistent response to management, although Rhizophagus irregularis was more abundant under no-tillage. Colonization intensity correlated with ASV richness rather than with individual taxa, suggesting that early symbiotic dynamics were linked to community diversity rather than to the dominance of specific lineages. These findings suggest that white mustard cover cropping, despite its well‑recognized agronomic benefits, may also carry context‑dependent shifts in AMF communities, highlighting a potential ecological trade‑off that should be considered when designing cover crop-tillage management combinations.

With escalating global health challenges, triclocarban (TCC) contamination has reemerged as a critical ecological threat, especially in wetland ecosystems. Yet, the mechanisms by which arbuscular mycorrhizal fungi (AMF) regulate plant root resistance and the rhizosphere environment under TCC exposure remain poorly understood. Here, we established an AMF-Phragmites communis symbiotic system and conducted TCC exposure experiments. Our results demonstrated that TCC exposure significantly inhibited mycorrhizal colonization, root morphology, and the antioxidant system of P. communis. Specifically, under the 5mg kg- 1 soil TCC exposure, arbuscule abundance decreased by 3.53-fold, root total length declined to 1011.13cm, and the integrated biomarker response index value of the antioxidant system dropped to 0.25. In contrast, arbuscular mycorrhizal (AM) symbiosis promoted root morphological and physiological growth. Transcriptome analysis revealed that AM symbiosis upregulated genes encoding key enzymes in the Mitogen-Activated Protein Kinase (MAPK) signaling pathway (e.g., MAPKKK and MAPK family members), whereas TCC exposure downregulated their expressions. Furthermore, in the rhizosphere soil, the composition and structure of microbial communities were distinctly influenced by AM symbiosis and TCC exposure. Compared to AM symbiosis, which upregulated soil metabolites associated with metabolism, TCC exposure downregulated soil metabolites across multiple functional categories, including metabolism, environmental information processing, and cellular processes. This research broadens our understanding of how AM symbiosis enhances the resistance of P. communis and maintains the stability of the rhizosphere environment under TCC exposure, and evidences the potential of AMF application in improving the purification capacity of wetland systems.

The Cerrado, Brazil's extensive tropical savanna, is recognized for its remarkable floristic heterogeneity, featuring a wide spectrum of vegetation types that transition from open grasslands to closed-canopy forests. In these ecosystems, arbuscular mycorrhizal fungi (AMF) play a crucial ecological role. A more in-depth understanding of AMF community patterns across these distinct environments is essential for the development of sustainable agricultural strategies and effective conservation protocols. Therefore, the present study evaluated the distribution and community dynamics of AMF across five primary Cerrado phytophysiognomies in the São Patrício Valley region in Goiás, Brazil: Campo Limpo, Campo Sujo, Cerradão, Stricto Sensu, and Veredas. Our findings confirm the occurrence of nine distinct AMF genera-Acaulospora, Claroideoglomus, Diversispora, Scutellospora, Sclerocystis, Glomus, Funneliformis, Gigaspora, and Ambispora-within the rhizospheric soil of the native vegetation. Furthermore, distinct ecological affinities were observed: Campo Limpo was strongly associated with Diversispora, Gigaspora, and Funneliformis. Conversely, Campo Sujo exhibited lower affinity for Sclerocystis and Scutellospora; Cerradão showed the lowest affinity for Sclerocystis and Gigaspora; and Stricto Sensu environments demonstrated the lowest affinity for Scutellospora and Funneliformis.

Aphid-microbe-plant interactions are fundamental to understanding plant responses to combined biotic and abiotic stress. The grain aphid Sitobion avenae is a major pest of wheat, particularly under drought conditions. Although arbuscular mycorrhizal fungi (AMF) can enhance plant tolerance to water deficit, their effects on aphid performance across wheat cultivars differing in drought resistance remain unclear. We examined the influence of Acaulospora delicata on S. avenae performance on two wheat cultivars-Yunhan-618 (drought-resistant) and Xinong-1376 (drought-susceptible)-under well-watered and water-deficit stress conditions. Under water-deficit stress conditions, root colonization by A. delicata was higher in both Yunhan-618 and Xinong-1376 when compared to well-watered conditions. In the absence of mycorrhiza, nymphal developmental time was prolonged, especially on drought-stressed Xinong-1376 plants. AMF inoculation shortened developmental time, increased adult longevity, and enhanced fecundity of S. avenae under both water regimes. On Yunhan-618, AMF association increased intrinsic growth rate and reproductive output of this aphid. Honeydew excretion by S. avenae was greater on AMF-inoculated plants under well-watered conditions. Aphid body mass and water balance traits were generally higher on AMF-associated Yunhan-618 plants under adequate water supply. Aphids also preferentially settled on AMF-inoculated drought-susceptible wheat plants under both water regimes as compared to drought-resistant wheat plants. Overall, A. delicata enhanced plant drought resilience but simultaneously promoted aphid fitness. These findings underscore the complex and context-dependent role of AMF in shaping plant-aphid interactions, with important implications for pest dynamics under climate change.

Arbuscular mycorrhizal fungi establish mutualistic associations with the roots of most vascular plants, enhancing plant immunity and activating mycorrhiza-induced resistance (MIR). MIR is a crucial mechanism for plant protection against a wide variety of attackers that is mediated by the priming of jasmonate-dependent defense responses, but the contribution of self-damage perception to MIR remains unexplored. We hypothesized that differential recognition of endogenous damage signals contributes to MIR in tomato plants. To test this hypothesis, we compared responses in mycorrhizal and non-mycorrhizal tomato plants after applying the cell-wall-derived damage signal oligogalacturonides (OGs). We explored early plant defense responses to OGs at the proteomic, metabolic, and transcriptomic levels, and the later effects on plant resistance to the necrotrophic pathogen Botrytis cinerea. We demonstrate that mycorrhizal plants are more sensitive to the damage signals, responding more strongly to lower doses than non-mycorrhizal plants. Mycorrhizal plants showed primed accumulation of defense proteins, receptor kinases, and flavonoids. Expression levels of the tomato wall-associated kinase 1 (slWAK1) gene were elevated in mycorrhizal plants, and MIR against B. cinerea was abolished in a wak1 mutant. Together, these results provide the first indication that self-damage recognition contributes to inducing MIR against B. cinerea.

Different AMF species regulate soil nitrogen transformation by guiding divergent cotton carbon investment strategies. Moderate inoculation with Acaulospora scrobiculata achieves optimal nitrogen benefits at minimal carbon cost. Arbuscular mycorrhizal fungi (AMF) form symbioses with most terrestrial plants, enhancing phosphorus and nitrogen uptake. However, the mechanisms by which different AMF species and inoculation dosages synergistically regulate host nitrogen uptake efficiency remain insufficiently elucidated. This study investigated three AMF species-Glomus heterosporum (Gh), Acaulospora scrobiculata (As), and Paraglomus occultum (Po)-at different inoculation dosages (440, 880, and 1320 spores g-1) on cotton growth, nitrogen uptake, plant carbon-to-nitrogen ratio, soil organic carbon input via hyphae, and soil enzyme activities. AMF significantly reduced soil organic carbon content and plant carbon-to-nitrogen ratio, altered soil enzyme activities, alleviated soil microbial nitrogen limitation, and promoted cotton growth and nitrogen uptake. At the moderate inoculation dosage (880 spores g-1), As exhibited the strongest promoting effect, increasing soil nitrogen acquisition-related enzyme activities by 103.7%, and enhancing shoot and root nitrogen accumulation by 3.46-fold and 2.40-fold, respectively. It effectively drives soil nitrogen transformation processes by guiding a moderate allocation of plant carbon. Gh exhibited the highest mycorrhizal nitrogen response at the high inoculation dosage (1320 spores g-1), but its carbon flow had limited stimulatory effects on nitrogen transformation. In contrast, the growth-promoting effect of Po and its ability to regulate soil nitrogen transformation were weaker. Furthermore, the AMF colonization rate was positively correlated with the mycorrhizal nitrogen and growth response, but negatively correlated with the input of soil organic carbon via the hyphal pathway. This study elucidates how carbon investment strategies directed by different AMF species regulate soil nitrogen transformation, supporting sustainable, AMF-based fertilization strategies in cotton cultivation.

Strigolactones (SLs) were initially identified as rhizosphere signals that trigger germination of parasitic weeds and promote branching in arbuscular mycorrhizal fungi. More recently, SLs have been characterized as a class of carotenoid-derived plant hormones that regulate plant architecture and stress responses. This review systematically summarizes their diverse functions in shaping shoot architecture and root development, as well as their ability to mediate acclimation to various abiotic and biotic stresses. It also discusses the canonical signaling module composed of D14, MAX2/D3, and D53/SMXLs and its extensive interactions with other hormonal pathways. Finally, this review suggests that future research should focus on elucidating the dynamic responses to environmental stress mediated by the SL pathway, decoding the functional diversification of SLs in different plant species, and leveraging SLs as rhizosphere signals to control parasitic weeds. Precise spatiotemporal modulation of SL activity is crucial for balancing its functional complexity and will contribute to designing crops with optimized plant architectures and enhanced stress resilience.

Subsistence agriculture in tropical smallholder farming systems of eastern Africa faces persistent productivity challenges due to low soil fertility, limited inputs, and increasing climate variability. Agroforestry can offer a sustainable strategy for smallholder systems by enhancing soil quality and influencing arbuscular mycorrhizal fungi (AMF) community composition in crop root systems. Using a canopy-based radial sampling design, we assessed the influence of Mangifera indica (mango) trees on soil properties and AMF communities in maize and cassava in southern Ethiopia. Illumina MiSeq sequencing identified 908 AMF operational taxonomic units (OTUs) from 7 families, dominated by Glomeraceae. While soil properties, including pH, total nitrogen (TN), organic carbon, and potassium, were significantly affected by the distance from mango trunks (p < 0.001), this was not the case for AMF community composition and AMF richness and diversity. Host identity, rather than distance from the mango trees, was the primary driver of AMF community composition, with distinct and host-specific assemblages in mango, maize, and cassava roots (p < 0.001). Soil nutrients influenced AMF diversity differently across host plants (p < 0.05). In maize-mango systems, TN positively affected observed richness (Sobs) and Shannon diversity (N1), whereas Olsen P negatively affected N1 and Simpson diversity (N2). In cassava-mango systems, TN increased Sobs, and Olsen P positively influenced expected richness (Sexp). Overall, these findings suggest that improvements in soil fertility associated with mango-based agroforestry systems do not necessarily translate into corresponding changes in crop-associated AMF community composition and diversity. Without demonstrating direct benefits, we at least show that mango can be effectively integrated into smallholder maize and cassava production without compromising the AMF communities, while enhancing key soil fertility indicators. Maintaining adequate nitrogen levels while avoiding excessive phosphorus inputs may help sustain stable AMF communities in agroforestry systems.

Sustainable intensification of soybean production requires strategies that simultaneously enhance plant growth, nutrient acquisition, and microbial symbiosis, particularly in nutrient-limited soils. This experiment investigated the combined effects of organic amendments (Biochar, Vermicompost) and microbial biofertilizers [encapsulated Rhizobium and arbuscular mycorrhizal fungi (AMF)] on the morphophysiological performance of black soybean (Glycine max). All treatments, the integration of Vermicompost and Biochar with dual inoculation (encapsulated Rhizobium + AMF) consistently produced the most pronounced improvements. Leaf area index and height-diameter ratio were significantly enhanced from 21days after planting onward, with the strongest canopy expansion and structural growth observed at 28days. Biomass of shoots and roots production was maximized under Biochar + dual inoculation, surpassing all other treatments. Phosphorus uptake was significantly elevated, and AMF root colonization reached 80%, the highest across treatments. This treatment also supported the greatest nitrogen-fixing bacterial population (7.63 × 105CFUg⁻1 soil), indicating synergistic microbial interactions. Data analyses confirmed that improvements in morphophysiology, nutrient acquisition, and microbial activity were strongly interrelated, with the majority of variance explained by coordinated responses under the Biochar + dual inoculation system. The integration of Biochar with encapsulated Rhizobium and AMF represents a highly effective strategy to enhance black soybean productivity and microbial symbiosis in Inceptisol, offering a promising pathway toward sustainable crop management.

Taxonomy of arbuscular mycorrhizal fungi (AMF) fungi (Glomeromycota) has long relied on spore morphological characteristics, which are distinguishable and evolutionarily stable structures in these fungi. Mode of spore formation and germination properties in AMF identify higher order taxa. Species level traits include external and internal spore morphology (e.g. size, color, spore wall structure, surface ornamentation) and some characteristics at the region of hyphal attachment. Comparative studies of AMF spore ontogeny led to a developmental model where characters were defined by their origin, position in ontogeny, and constraints on variation. The goals of this work are (i) to revisit the spore developmental model, the model's premises and interpretations for morphological taxonomy of AMF, (ii) to describe and compare the main modes of spore formation as the first step to define taxa, and (iii) to organize these data into dichotomous keys as a tool for AMF species identification. Such an aid will facilitate a more accurate identification of fungal specimens collected and investigated in field-based and ecological studies, in organization and maintenance of germplasm deposited in culture collections, and in production and utilization of commercial inoculants.

Zeolite-AMF application enhances wheat productivity, cadmium immobilization, and saline soil health under Cd-contaminated wastewater irrigation.

Arbuscular mycorrhizal fungi (AMF) form symbiotic associations with plant roots and play a significant role in improving plant nutrition and growth. To enrich and propagate the indigenous arbuscular mycorrhizal fungal communities associated with Khasi mandarin (Citrus reticulata), trap cultures were established using field-collected rhizospheric soil and root fragments. Rhizophagus irregularis was isolated from the trap culture and identified by amplifying the SSU region of 18S rDNA. Bacterial isolates associated with AMF spores have been isolated from both the outer and inner spore surfaces. The isolates were identified by amplifying and sequencing the 16S rDNA region. All bacterial isolates were tested for their plant growth-promoting properties, such as phosphate solubilization, indole-3-acetic acid (IAA) production, siderophore production, and extracellular enzyme activity. The findings revealed major functional differences between bacteria on the spore surface and those found inside the spores. Selected promising isolates were then tested for their capacity to promote plant growth in maize and Khasi mandarin under controlled conditions. Plants treated with AMF and selected bacterial isolates exhibited significantly improved growth characteristics compared with untreated controls.

Melanoxylum brauna Schott is an endangered Atlantic Forest tree species whose seedling production is constrained by low survival under nursery conditions. This study evaluated seedling survival, morphophysiological performance, biochemical traits, and arbuscular mycorrhizal fungi (AMF) occurrence in seedlings produced from seeds collected at two locations and cultivated under different substrate combinations. Treatments included organic substrate, subsoil, soil collected near mother trees, and mixtures of sand, subsoil, mother-tree soil, and ground branches. Seedlings grown in 100% soil collected near mother trees showed the highest survival rate (97.5%), superior Dickson quality index, greater shoot and root growth, and enhanced photochemical efficiency (Fv/Fm), regardless of seed origin. These soils exhibited higher AMF spore density and the presence of Glomus macrocarpum, Sclerocystis spp., and Gigaspora spp., whereas organic substrates lacked mycorrhizal propagules and resulted in complete seedling mortality after 60 days. Biochemical analyses revealed increased accumulation of carbohydrates, proteins, lipids, and starch in seedlings grown in mother-tree soils, indicating improved metabolic performance. Overall, the results indicate that soil collected near mother trees functions as a natural bioinoculum source and is associated with improved seedling growth, physiology, and survival, possibly mediated by native microbial communities, including AMF.

Manganese (Mn) toxicity, exacerbated by soil acidification and anthropogenic pollution, poses a significant threat to plant growth and ecosystem health, particularly in economically important citrus plants. This study tried to uncover the mechanisms by which the arbuscular mycorrhizal fungus Funneliformis mosseae enhances Mn tolerance in trifoliate orange (Poncirus trifoliata) seedlings under excess Mn stress (20 mmol/L MnSO4). Although Mn stress inhibited root colonization by F. mosseae, inoculation with F. mosseae significantly alleviated the Mn-induced suppression of plant growth, root system architecture, photosynthetic efficiency, and photochemical activity of photosystem II. Crucially, AMF colonization reduced Mn accumulation in leaves, stems, and roots, alongside decreased the Mn bioconcentration and translocation factors. Mechanistically, F. mosseae enhanced Mn tolerance in trifoliate orange through two complementary strategies: external exclusion and internal detoxification. Externally, F. mosseae increased levels of difficultly extractable glomalin-related soil protein to sequestrate Mn in the rhizosphere, and significantly upregulated fungal suppressor of mitochondrial fission genes (FmSMF1 and FmSMF2) to enhance hyphal sequestration, thereby blocking Mn entry into roots. Internally, F. mosseae modulated the subcellular distribution and chemical forms of Mn in trifoliate orange: they promoted Mn compartmentalization into the cell wall and soluble (vacuolar) fractions, while reducing its accumulation and proportion in sensitive organelles such as chloroplasts and mitochondria. Furthermore, Mn was transformed from highly active, toxic forms (ethanol- and water-extractable) into more stable, inert forms (e.g., pectate- and phosphate-bound). Consistent with the reduced Mn uptake and toxicity, the expression of host metal tolerance protein (PtMTP8 and PtMTP11) and superoxide dismutase (PtMnSOD) genes was significantly downregulated in mycorrhizal roots under Mn toxicity. In conclusion, F. mosseae enhances Mn tolerance in trifoliate orange through a synergistic dual mechanism, establishing an external barrier via fungal-mediated immobilization and building an internal defense line by reprogramming host Mn compartmentalization and detoxification pathways, thereby minimizing Mn phytotoxicity.

Decoding stage-specific symbiotic programs in the Rhizophagus irregularis-tomato interaction using single-nucleus transcriptomics.

The role of cover crops in promoting the abundance of beneficial soil microbes is increasingly gaining attention in tree crops. However, soil fungi remain comparatively understudied despite their roles in nutrient cycling and soil organic matter turnover, functions that are directly influenced by cover crops and may, in turn, affect the cash crop. This study compared the effects of cover crop mixtures to a weedy control on soil bacterial and fungal communities in young (< 10 years) and old (> 20 years) citrus orchards-with different lengths of cover cropping-across three soil depths over 2 years. Soil fungi responded to cover crops, whereas soil bacteria showed minimal changes in both orchards. In the young orchard, non-legume cover crop mixtures altered soil fungal communities three months after planting and after 2 years, both cover crop mixtures resulted in distinct community shifts relative to the control. In the old orchard, soil depth shaped fungal communities, with the strongest cover crop effects in the topsoil and subsurface soil. In both orchards, cover crops enriched potentially plant-beneficial microbial taxa, including arbuscular mycorrhizal fungi, highlighting the importance of cover crops as a management tool for driving fungal-mediated ecological processes and soil health benefits in orchard systems.

A trade-off between high grain yield and high protein (or nitrogen, N) concentration is frequently observed for crop plants in agroecosystems and is difficult to resolve using conventional agricultural methods. Whether ecological strategies, such as exploring the interactions between plants and microbes, can be leveraged to tackle this problem remains unclear. Here, we used wheat as a model plant and focused on the interaction among plants, arbuscular mycorrhizal fungi (AMF) and hyphosphere bacteria. We conducted six independent but complementary experiments and demonstrated that AMF can enhance both wheat yield and grain N concentration, but only in specific varieties with high N conversion efficiency (grain yield per mean plant N at preanthesis). AMF can boost yield from increased grain weight via enhanced postanthesis photosynthetic carbon (C) assimilation through promoting plant phosphorus uptake, while elevating grain N concentration through stimulating postanthesis N uptake and assimilation. This dual effect arises from the enhanced postanthesis belowground C allocation, sustaining AMF hyphal network integrity and increasing soil nutrient availability via reshaping hyphosphere bacterial community structure. Our findings indicate that postanthesis plant-microbial interactions can potentially overcome an old dilemma between maximizing grain yield and N concentration in agricultural production.

Plant growth-promoting microorganisms (PGPMs) and biochar are increasingly recognized as sustainable strategies to enhance crop performance; however, their comparative and integrative effects on carbon-water coordination and leaf thermal regulation under soilless substrate conditions remain poorly resolved. We investigated the physiological responses of Vigna radiata L. to bacterial biostimulant (BB), arbuscular mycorrhizal (AM) fungi, their co-inoculation (BA), and BA combined with biochar (BiB). All treatments enhanced biomass relative to the uninoculated control, but through distinct physiological mechanisms. BB reduced leaf temperature (LT) primarily via increased stomatal conductance and transpiration, supporting higher net photosynthesis. In contrast, AM enhanced plant water status, as reflected by higher relative water content, and maintained intrinsic water-use efficiency comparable to the control but greater than in the other inoculation treatments. The reduction in LT under AM, despite unchanged transpiration, may reflect differences in plant water relations rather than purely evaporative cooling. BA integrated these complementary functions, resulting in the lowest LT, and maximum biomass. BiB further enhanced photosynthetic rate and maintained intrinsic water-use efficiency, although biomass was slightly lower than in BA. Collectively, the results demonstrate that the distinct physiological roles of bacterial and mycorrhizal inoculants, stomatal-driven carbon acquisition versus hydraulic stabilization, become functionally complementary under co-inoculation, enabling coordinated regulation of carbon assimilation, water balance, and leaf thermal dynamics to maximize biomass production. By reducing leaf temperature, PGPMs could contribute to maintaining photosynthetic efficiency under potential heat stress.