Search Results (120)

The use of biostimulants offers a sustainable strategy to improve crop quality. This study assessed the effects of an arbuscular mycorrhizal fungi inoculum (consisting of species Claroideoglomus claroideum, Claroideoglomus etunicatum, Funneliformis geosporum, Funneliformis mosseae and Rhizophagus irregularis) and an 0.5% aqueous extract of Landoltia punctata on the growth and biochemical composition of lettuce (Lactuca sativa L. cv. ‘Dubáček’) under indoor conditions. Four variants were tested: control (C), mycorrhiza (M), L. punctata extract (L), and their combination (M + L), with biometric, physiological, and biochemical parameters evaluated. Simultaneously, the amino acid profile of Landoltia extract was determined, and the degree of plant colonization by mycorrhizal fungi was evaluated. While biostimulant treatments did not affect above-ground biomass, L. punctata extract (L and M + L) significantly raised chlorophyll a (by 15.9% and 16.0%) and chlorophyll b (by 55.5% and 42.8%) compared to the control. The combined treatment (M + L) achieved the highest total phenolic content (254.28 mg/kg). All treated variants significantly reduced leaf nitrate content, with M and M + L being most effective (−35.1% and −33.6%). Amino acid metabolomic analysis showed that the extract is rich in γ-aminobutyric acid, valine, phenylalanine, tryptophan, and other proteinogenic amino acids that may drive its biostimulant effects. Microscopy confirmed successful root colonisation in mycorrhizal variants (58% in M, 42% in M + L). Although the biostimulants did not significantly affect growth, their application is recommended to improve lettuce quality by enhancing photosynthetic pigments and phenolic compounds while reducing nitrate content, indicating their potential for producing safe, higher-quality crops. Full article

Arbuscular mycorrhizal (AM) fungi establish mutualistic symbioses with plant roots, enhancing plant growth and improving soil fertility through nutrient exchange. Among these, soil nitrogen (N) and phosphorus (P) are critical for symbiosis formation, directly influencing nutrient uptake and translocation within the symbiotic system. This study aimed to examine the regulatory roles of N and P levels on AM fungal development and associated bacterial communities in culture. Sorghum was used as the host plant in pot experiments with two AM fungi, Rhizophagus irregularis and Funneliformis mosseae, under varying N and P concentrations. The analyzed parameters included mycorrhizal colonization, propagule production, plant biomass, nutrient contents (N, P, and K), and bacterial community diversity. N3P1 treatment (150 mg/L N, 30 mg/L P) yielded the highest colonization rate, spore production, and arbuscule abundance in both AM fungal symbionts. At equivalent N and P concentrations, the N, P, and K contents in inoculated plants were significantly higher than those in controls. AM fungal inoculation markedly increased the bacterial diversity in the culture (Shannon index raised by 15.2–28.7%) and enriched beneficial taxa, such as Bradyrhizobium and Pseudomonas. N and P concentrations substantially influenced AM fungal symbiosis, with optimal development observed under N3P1 conditions. By regulating AM symbiotic establishment, N and P levels reshaped microbial community composition, providing theoretical guidance for industrialized AM fungal cultivation and inoculant production. Full article

Areca (Areca catechu L.) is an important economic crop in tropical regions, but excessive nitrogen application leads to low nitrogen fertilizer utilization efficiency (approximately 30%). Vanilla (Vanilla planifolia Andrews) can be intercropped with areca to enhance land use efficiency. However, the impact of combined nitrogen reduction and Arbuscular mycorrhizal fungi (AMF) inoculation on the intercropping system of areca and vanilla remains unclear. This study examined the impact of nitrogen reduction (at levels of conventional fertilization, a 30% reduction and a 60% reduction) and the inoculation of AMF on the photosynthetic characteristics, physiological metabolism, and nitrogen utilization within an areca and vanilla intercropping system, employing a two-factor experimental design. The nitrogen reduction significantly inhibited SPAD value (chlorophyll content) (decreased by 46.21%), net photosynthesis (P_n) (decreased by 71.13%), and transpiration rate (T_r) (decreased by 44.34%) of vanilla without inoculation of AMF, but had little effect on the photosynthesis of areca. Inoculation with AMF, notably Funneliformis mosseae, alleviated the adverse effects of reduced nitrogen on vanilla. The net photosynthesis and intercellular CO₂ concentration (C_i) significantly increased by 76.23% and 69.48%, respectively. Additionally, the nitrogen uptake efficiency of the areca was improved, with root vitality increasing by 39.96%. Additionally, AMF enhanced the activities of acid phosphatase (ACP) (increased by 38.86% in vanilla) and nitrate reductase (NR) (increased by 53.77% in areca), promoting soil mineral nutrient activation and nitrogen metabolism. The nitrogen reduction combined with AMF inoculation can improve the nitrogen use efficiency of the areca and vanilla intercropping system, revealing its synergistic mechanism in the tropical intercropping system. Full article

Saffron (Crocus sativus L.), a perennial plant of the Iridaceae family, which is also known as “red gold”, is one of the most expensive spices throughout the world. Originally, it was mainly used as a condiment and natural dye for food, and as a medicinal plant in folk medicine. Its cultivation is characterized by an extensive use of labor, since most of the crop management techniques (e.g., sowing, weeding, flower picking, and stigma separation) are performed manually. The aim of this work is to investigate how the adoption of sustainable cultivation techniques could improve the profitability of saffron at the primary level. Thus, economic and technical data were collected directly on a farm in a marginal area in Northwestern Italy, in order to compare the productivity and profitability of traditional and innovative cultivation techniques. The effect of sustainable practices, such as the use of beneficial microorganisms, that is, arbuscular mycorrhizal fungi (AMF), on the productivity of saffron was considered. In a previous work, AMF inoculation with Rhizophagus intraradices and Funneliformis mosseae led to an increase in the flower and saffron spice yields, compared to uninoculated controls. The profitability of the saffron (including tepals, its by-product) considered in our case study, expressed as economic profit (pure profit), was found to be slightly negative for the traditional cultivation method (without the use of AMF) and also, albeit to a lesser extent, for the innovative technology (with the use of AMF). This slightly negative result is mainly due to the implicit cost of family labor for both the traditional and innovative cultivation techniques. The results of our study can be considered a further step in favor of the use of cultivation techniques that improve crop productivity and, at the same time, are sustainable. They also support the spread of minor crops, which, nevertheless, are important to maintain agricultural activities in marginal territories. Full article

Arbuscular mycorrhizal fungi (AMF) play a crucial role in the soil–plant interface, yet the combined effects of AMF inoculation and phosphorus (P) addition on soil–plant nitrogen (N) and P, as well as oat grain yield, under drought stress remain unclear. Experiments were conducted during the 2021 and 2022 oat-growing seasons, applying AMF (40 g inoculum per pot; sterilized inoculum as the NAMF control) and P (0, 20, and 40 mg kg⁻¹ soil, designated P0, P1, and P2) under 75% and 55% relative water content. This study found that AMF inoculation at the P1 level significantly improved the AMF colonization rate, grain yield, and partial factor productivity of P (PFP_P) of oat. The grain yield increased by 6.2% (2021) and 9.8% (2022) under drought stress compared to the AMF-free treatment. AMF inoculation and P addition showed interactive effects on soil–plant N and P dynamics, which significantly increased microbial biomass phosphorus (MBP), nitrate N, and the available P content in oat soil. P1AMF significantly increased the total N and P contents under drought stress compared to P1NAMF, with maximum increments of 40.7% (N) and 11.1% (P) in 2021 and 15.4% (N) and 32.3% (P) in 2022. Moreover, the P1AMF treatment significantly improved P recovery efficiency (PRE), achieving a maximum increase of 48.4% across the two-year study. The analysis revealed that soil MBP was the key factor influencing oat grain yield, as well as the total N and P content in oat plants. It was concluded that AMF inoculation with a moderate amount of P addition could effectively regulate soil N and P availability and enhance plant N and P contents, as well as P productivity and use efficiency, thereby improving oat drought tolerance. Soil MBP acted as a vital bridge in the oat soil–plant continuum. Full article

Arbuscular mycorrhizal (AM) fungi can have complicated interactions with plants and soils, which play a critical role in mediating the soil carbon cycle. However, the mechanism by which AM fungi regulate soil respiration is not well documented. This study conducted a completely randomized block-design mesocosm experiment using the inoculation of AM fungi (RI: Rhizophagus intraradices; FM: Funneliformis mosseae) with Fraxinus malacophylla to identify the pathways of AM fungi controlling soil respiration in a rocky desertification habitat. We observed that the average soil respiration rates (3.78 μmol·m⁻²·s⁻¹) were significantly higher in two AM fungi inoculation treatments than in the control (2.87 μmol·m⁻²·s⁻¹). Soil respiration rates were 1.59-fold higher in RI fungi inoculation and 1.05-fold higher in FM inoculation than in the control. Explanation rates of microbial biomass carbon, biomass nitrogen, and root biomass in RI (57.46–76.49%) and FM (44.81–62.62%) inoculation for soil respiration variation were higher than those in the control (24.51–34.32%). The direct positive pathway of soil respiration was mainly regulated by microbial biomass (59.5%) and root biomass (34.90%), while the indirect positive contributions of soil physicochemical properties (30.00%), colonization level (3.50%), soil microclimate (19.30%), and enzyme activity (3.38%) to respiration dynamics ranked second. Thus, we conclude that soil respiration dynamics can be mainly controlled by AM fungi-mediated changes in microbial and root biomass in rocky desertification areas. Full article

Mycorrhizal symbiosis relies on the host’s supply of carbohydrates, while sugar transport within plants is governed by the SWEET sugar transporter family. Although the symbiotic association between arbuscular mycorrhizal fungi (AMF) and maize is critical for its growth and sugar regulation, different AMF species have varying impacts on the host. The aim of this study was to analyze the effects of inoculating six different AMF species [Diversispora epigaea (De), Rhizophagus intraradices (Ri), Paraglomus occultum (Po), Entrophospora etunicata (Ee), Glomus heterosporum (Gh), and Funneliformis mosseae (Fm)] on plant growth, leaf photosynthetic capacity, glomalin-related soil protein content, leaf sugar content, and SWEET gene expression of maize under potted conditions for two months. AMF species colonize maize roots and showed significant species-specific variation, where Ri and Fm colonized treatment had the greatest rates (66~68%). All six fungi significantly increased biomass and stem diameter, with Ee treatment yielding the thickest stems, and enhanced leaf photosynthetic performance and glomalin-related soil protein fractions to some extent, with species-specific enhancements. All AMF species in particular significantly increased leaf sucrose; all except Ri treatment significantly increased fructose; while only Po and Fm treatments significantly increased glucose. AMF inoculations consistently upregulated the expression of ZmSWEET1b/3a/3b/4a/4b/14a and 16 genes, consistently downregulated the expression of ZmSWEET6b/11b/12a/13a/13b/13c and 17b genes, and induced treatment-specific regulation in the other gene expression. Root AMF colonization clustered with sugars and specific ZmSWEETs, with ZmSWEET4a/15b and 14b central to sucrose/glucose based on principal component analysis, indicating that these genes have specific regulatory effects in response to AMF treatments. In short, AMF inoculation reprogrammed ZmSWEET expression in a species-specific manner, with core ZmSWEET genes mediating sugar accumulation to support symbiosis. Full article

Flavonoids serve as crucial plant antioxidants in drought tolerance, yet their antioxidant regulatory mechanisms within mycorrhizal plants remain unclear. In this study, using a two-factor design, trifoliate orange (Poncirus trifoliata (L.) Raf.) seedlings in the four-to-five-leaf stage were either inoculated with Funneliformis mosseae or not, and subjected to well-watered (70–75% of field maximum water-holding capacity) or drought stress (50–55% field maximum water-holding capacity) conditions for 10 weeks. Plant growth performance, photosynthetic physiology, leaf flavonoid content and their antioxidant capacity, reactive oxygen species levels, and activities and gene expression of key flavonoid biosynthesis enzymes were analyzed. Although drought stress significantly reduced root colonization and soil hyphal length, inoculation with F. mosseae consistently enhanced the biomass of leaves, stems, and roots, as well as root surface area and diameter, irrespective of soil moisture. Despite drought suppressing photosynthesis in mycorrhizal plants, F. mosseae substantially improved photosynthetic capacity (measured via gas exchange) and optimized photochemical efficiency (assessed by chlorophyll fluorescence) while reducing non-photochemical quenching (heat dissipation). Inoculation with F. mosseae elevated the total flavonoid content in leaves by 46.67% (well-watered) and 14.04% (drought), accompanied by significantly enhanced activities of key synthases such as phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS), chalcone isomerase (CHI), 4-coumarate:coA ligase (4CL), and cinnamate 4-hydroxylase (C4H), with increases ranging from 16.90 to 117.42% under drought. Quantitative real-time PCR revealed that both mycorrhization and drought upregulated the expression of PtPAL1, PtCHI, and Pt4CL genes, with soil moisture critically modulating mycorrhizal regulatory effects. In vitro assays showed that flavonoid extracts scavenged radicals at rates of 30.07–41.60% in hydroxyl radical (•OH), 71.89–78.06% in superoxide radical anion (O₂^•−), and 49.97–74.75% in 2,2-diphenyl-1-picrylhydrazyl (DPPH). Mycorrhizal symbiosis enhanced the antioxidant capacity of flavonoids, resulting in higher scavenging rates of •OH (19.07%), O₂^•− (5.00%), and DPPH (31.81%) under drought. Inoculated plants displayed reduced hydrogen peroxide (19.77%), O₂^•− (23.90%), and malondialdehyde (17.36%) levels. This study concludes that mycorrhizae promote the level of total flavonoids in trifoliate orange by accelerating the flavonoid biosynthesis pathway, hence reducing oxidative damage under drought. Full article

Arbuscular mycorrhizal fungi (AMF) symbiosis has great potential in improving grapevine performance and reducing external input dependency in viticulture. However, the precise, strain-specific impacts of different AMF species on ‘Summer Black’ grapevine cuttings across multiple physiological and morphological dimensions remain underexplored. To address this, we conducted a controlled greenhouse pot experiment, systematically evaluating four different AMF species (Diversispora versiformis, Diversispora spurca, Funneliformis mosseae, and Paraglomus occultum) on ‘Summer Black’ grapevine cuttings. All AMF treatments successfully established root colonization, with F. mosseae achieving the highest infection rate. In detail, F. mosseae notably enhanced total root length, root surface area, and volume, while D. versiformis specifically improved primary adventitious and 2nd-order lateral root numbers. Phosphorus (P) uptake in both leaves and roots was significantly elevated across all AMF treatments, with F. mosseae leading to a 42% increase in leaf P content. Furthermore, AMF inoculation generally enhanced the activities of catalase, superoxide dismutase, and peroxidase, along with soluble protein and soluble sugar contents in leaves and roots. Photosynthetic parameters, including net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr), were dramatically increased in AMF-colonized cutting seedlings. Whereas, P. occultum exhibited inhibitory effects on several growth metrics, such as shoot length, leaf and root biomass, and adventitious lateral root numbers, and decreased the contents of Nitrogen (N), potassium (K), magnesium (Mg), and iron (Fe) in both leaves and roots. These findings conclusively demonstrate that AMF symbiosis optimizes root morphology, enhances nutrient acquisition, and boosts photosynthetic efficiency and stress resilience, thus providing valuable insights for developing targeted bio-fertilization strategies in sustainable viticulture. Full article

The present research focused on the physiological alterations and antioxidant potential of Portulaca oleracea L. due to mycorrhizal symbiosis with diverse strains. Purslane belongs to the plants that form a symbiosis with mycorrhizal fungi and show tolerance to various strains. Inoculation with Funneliformis mosseae gave better mycorrhizal colonization results and positively affected biomass accumulation and the concentration of reducing sugars. The total accumulation of plastid pigments was higher in symbiotic plants, although this effect was not specific to any particular strain. Mycorrhizal fungi increased the levels of carotenes in the shoots, while xanthophylls decreased, with the highest values observed in non-inoculated plants. Both strains influenced the ratio of betalains: Funneliformis mosseae promoted the accumulation of β-cyanins, while Claroideoglomus claroideum increased β-xanthines. The association with Funneliformis mosseae also affected antioxidant capacity, as indicated by the FRAP test, by altering the concentrations of secondary metabolites, particularly phenols and flavonoids. Targeted inoculation with specific strains boosts both non-enzymatic (including water-soluble and lipid-soluble metabolites) and enzymatic antioxidant activity; however, it was not dependent on the strain. These findings underscore the benefits of mycorrhizal associations in purslane cultivation, promoting sustainable ecological practices and enhancing its quality as a food product. Full article

Arbuscular mycorrhizae fungi (AMF) plays an important role in plants’ response to environmental stress, and the main environmental stress encountered in grape production is high temperature stress. This study aims to inoculate Funneliformis mosseae (A type of AMF) on grapes and investigate their tolerance to high temperature stress after inoculation. The results showed that AMF could infect grape roots, and the mycorrhizal infection rate was 20.78%. After inoculation with AMF, the growth of grape plants was significantly better than that in the non-inoculation group. Compared with the uninoculated group, the net photosynthetic rate, transpiration rate and stomatal conductance were higher in the AMF group, and the intercellular CO₂ concentration was lower. After high temperature treatment, there was no significant difference in the content of hydrogen peroxide (H₂O₂) in grape leaves between the two experimental groups at each time, and the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and other enzymes showed great differences, especially after high temperature treatment for 6 h. The activities of SOD, POD and CAT in AMF group were significantly higher than those in uninoculated group. The content of malondialdehyde (MDA) in grape leaves of the two experimental groups had no significant difference between 0 h and 3 h after high temperature treatment, and the MDA content in the AMF group was significantly lower than that in the uninoculated group after 6 h of high temperature treatment. The contents of soluble sugar and soluble protein in the AMF group were higher than those in the uninoculated group at all time periods, especially after 6 h of high temperature treatment. In addition, we found that VvHSP70, VvHSP17.9, VvGLOS1, VvHSFA2 genes all responded to high temperature stress, but there was no significant difference between the AMF group and the uninoculated group. It can be seen from the above that AMF can significantly enhance the adaptability of grape plants to high temperature stress by improving photosynthetic efficiency, antioxidant enzyme activity, soluble sugar and soluble protein content, and reduce Malondialdehyde (MDA) content, which provides guidance and theoretical basis for grape production. Full article

Selenium (Se) is an important micronutrient for the maintenance of human health. In China, however, the population is more severely deficient in Se. Soybean is an important grain and oil crop in the world and serves as a major dietary source. The development of Se biofortification of soybeans may be an effective measure to address human Se deficiency. Arbuscular mycorrhizal fungi (AMF) are ubiquitous soil microorganisms that can enhance nutrient uptake in host plants. So, it is necessary to investigate whether soybean inoculated with AMF can biofortificate Se. In this experiment, we studied the impact of the exogenous application of three Se species (selenite, selenate, and selenomethionine) and two AMF species (Funneliformis mosseae and Glomus versiforme) on Se uptake in soybean seedlings. The results showed that the inoculation of AMF significantly (p < 0.05) improved biomass and P concentration in soybeans. Regardless of exogenous Se addition, the inoculation of AMF improved the Se transfer factor and significantly (p < 0.05) increased Se translocation to the soybean shoot. The inoculation of AMF also significantly (p < 0.05) increased the percentage of available Se in soil with selenite addition. Based on these findings, the combined application of exogenous Se and AMF inoculation represents a viable strategy for the Se biofortification of soybeans. Full article

The remediation of lead (Pb)-contaminated soils through eco-friendly strategies is critical for sustainable agriculture. This study investigated the role of arbuscular mycorrhizal fungi (AMF) in enhancing maize tolerance to Pb stress and modulating rhizosphere microbial communities. A pot experiment was conducted with maize (Baiyu833) under four Pb concentrations (0, 900, 1800, 2700 mg·kg⁻¹) and three AMF treatments: non-inoculation (Non), Funneliformis mosseae (Fm), or Rhizophagus intraradices (Ri). The results demonstrated that AMF inoculation significantly increased plant biomass, boosted antioxidant enzyme activities (SOD, POD), and reduced malondialdehyde (MDA) levels, mitigating Pb-induced oxidative stress. AMF restricted Pb translocation to aerial parts, with root Pb accumulation reaching 2110.76 mg·kg⁻¹ (Fm) and 2090.56 mg·kg⁻¹ (Ri) under Pb2700, enhancing phytostabilization. High-throughput sequencing revealed that AMF inoculation enriched α-diversity indices and restructured bacterial communities, favoring beneficial taxa like Promicromonospora, which are linked to heavy metal resistance and plant growth promotion. Principal coordinate analysis highlighted distinct clustering of microbial communities driven by AMF, emphasizing their role in alleviating Pb toxicity. These findings underscore that AMF enhance maize resilience to Pb by regulating antioxidant defense, immobilizing Pb in roots, and recruiting stress-tolerant rhizosphere microbiomes. This study provides insights into AMF-assisted phytoremediation as a sustainable strategy for Pb-contaminated soils. Full article

Grapevines (Vitis vinifera L.) face significant challenges from abiotic stresses caused by climate change, including drought, salinity, and temperature extremes. This comprehensive review examined the role of beneficial microorganisms in enhancing grapevine tolerance to these stresses, focusing on arbuscular mycorrhizal fungi (AMF), plant growth-promoting rhizobacteria (PGPR), and endophytes. The study analyzes species-specific effects and their molecular mechanisms, highlighting how single and consortium inoculations improve plant resilience. AMF species, particularly Funneliformis mosseae and Rhizophagus irregularis, demonstrated significant enhancement in drought and salinity tolerance through improved nutrient uptake and stress response modulation. The PGPRs, Bacillus and Pseudomonas species, show remarkable abilities to mitigate various abiotic stresses through mechanisms including phytohormone production and antioxidant defense enhancement. Endophytic microorganisms such as Pseudomonas fluorescens RG11 and Serendipita indica play crucial roles in stress mitigation through melatonin production and improved water retention, respectively. The synergistic effects of combined AMF, PGPR, and PGPF applications led to a significant increase in grapevine drought and salinity tolerance, improving nutrient uptake, photosynthesis rates, and antioxidant defense mechanisms. Molecular analysis revealed that these microbial consortia regulate the expression of stress-responsive genes, particularly VvNCED and VvP5CS, enhancing grapevine resilience through improved osmotic adjustment, ROS scavenging, and hormonal regulation. These findings provide valuable insights into the molecular pathways underlying stress tolerance, offering promising strategies for sustainable viticulture under climate change. Full article

Contaminants of emerging concern, such as pharmaceuticals (PhACs), are continuously introduced into agro-ecosystems through irrigation with treated wastewater (TWW). While this practice is increasingly common in drought regions, only limited information is available on the fate of PhACs within the soil–plant system. For this purpose, a two-year study was conducted by irrigating artichokes, non-inoculated and inoculated with different arbuscular mycorrhizal fungi, with water containing PhACs at different concentrations. The experiment, conducted in both open field and pot conditions, aimed to evaluate their potential accumulation in the soil and plant tissues. Results showed that PhACs concentrations varied according to the physicochemical properties of the compounds and the duration of irrigation. The study revealed minimal accumulation of contaminants in the soil and non-edible plant parts. This was observed only at the end of the second growing cycle, when the plants were irrigated with TWW containing trace PhAC levels. In contrast, during both pot cultivation cycles, PhACs accumulated in the soil were translocated into plant organs when irrigated with water enriched to 200 μg L⁻¹ with eight PhACs. At the end of the trial, climbazole had the highest concentration in soil, while carbamazepine and fluconazole showed greater accumulation across all plant organs compared to other PhACs. In both trials, plants inoculated with Septoglomus viscosum absorbed less PhACs compared to those inoculated with Rhizophagus irregularis + Funneliformis mosseae. These results suggest that, while the long-term use of TWW containing PhACs may improve artichoke yield, it could present different degrees of risk to both environmental and human health, depending on the concentration levels of contaminants. Full article