Characterization and Aggressiveness of Take-All Root Rot Pathogens Isolated from Symptomatic Bermudagrass Putting Greens.

Take-all root rot is a disease of ultradwarf bermudagrass putting greens caused by Gaeumannomyces graminis (Gg), Gaeumannomyces sp. (Gx), Gaeumannomyces graminicola (Ggram), Candidacolonium cynodontis (Cc), and Magnaporthiopsis cynodontis (Mc). Many etiological and epidemiological components of this disease remain unknown. Improving pathogen identification and our understanding of the aggressiveness of these pathogens along with growth at different temperatures will advance our knowledge of disease development to optimize management strategies. Take-all root rot pathogens were isolated from symptomatic bermudagrass root and stolon pieces from 16 different golf courses. Isolates of Gg, Gx, Ggram, Cc, and Mc were used to inoculate 'Champion' bermudagrass in an in planta aggressiveness assay. Each pathogen was also evaluated at 10, 15, 20, 25, 30, and 35°C to determine growth temperature optima. Infected plant tissue was used to develop a real-time PCR high-resolution melt assay for pathogen detection. This assay was able to differentiate each pathogen directly from infected plant tissue using a single primer pair. In general, Ggram, Gg, and Gx were the most aggressive while Cc and Mc exhibited moderate aggressiveness. Pathogens were more aggressive when incubated at 30°C compared with 20°C. While they grew optimally between 24.4 and 27.8°C, pathogens exhibited limited growth at 35°C and no growth at 10°C. These data provide important information on this disease and its causal agents that may improve take-all root rot management.

Draft Genome Sequences of Two Phytoplasma Strains Associated with Sugarcane Grassy Shoot (SCGS) and Bermuda Grass White Leaf (BGWL) Diseases.

We performed whole-genome sequencing of two phytoplasmas associated with sugarcane grassy shoot (SCGS) and Bermuda grass white leaf diseases. These are the first draft genomes of SCGS phytoplasma (strain SCGS) and 'Candidatus Phytoplasma cynodontis' (strain LW01) and may help to delineate these phytoplasmas at a finer taxonomic level.

Multiplex End-Point PCR for the Detection of Three Species of Ophiosphaerella Causing Spring Dead Spot of Bermudagrass.

A multiplex end-point polymerase chain reaction (PCR) assay was developed for identifying the three-fungal species in the genus Ophiosphaerella that cause spring dead spot (SDS), a devastating disease of bermudagrass. These fungi are difficult to identify by morphology because they seldom produce pseudothecia. To achieve species-specific diagnosis, three pairs of primers were designed to identify fungal isolates and detect the pathogen in infected roots. The internal transcribed spacer region, the translation elongation factor 1-α, and the RNA polymerase II second-largest subunit were selected as targets and served as templates for the design of each primer pair. To achieve uniform melting temperatures, three to five random nucleotide extensions (flaps) were added to the 5' terminus of some of the designed specific primers. Temperature cycling conditions and PCR components were standardized to optimize specificity and sensitivity of the multiplex reaction. Primers were tested in multiplex on DNA extracted from axenic fungal cultures and from field-collected infected and uninfected roots. A distinct amplicon was produced for each Ophiosphaerella sp. tested. The DNA from Ophiosphaerella close relatives and other common bermudagrass pathogens did not amplify during the multiplex assay. Metagenomic DNA from infected bermudagrass produced species-specific amplicons while DNA extracted from noninfected roots did not. This multiplex end-point PCR approach is a sensitive and specific molecular technique that allows for correct identification of SDS-associated Ophiosphaerella spp. from field-collected roots.

Amelioration of Salt Stress on Bermudagrass by the Fungus Aspergillus aculeatus.

There is considerable evidence that plant abiotic-stress tolerance can be evoked by the exploitation of a globally abundant microbe. A. aculeatus, which was initially isolated from the rhizosphere of bermudagrass, has been shown to increase heavy metal tolerance in turfgrasses. Here, we report on the potential of A. aculeatus to induce tolerance to salt stress in bermudagrass. Physiological markers for salt stress, such as plant growth rate, lipid peroxidation, photosynthesis, and ionic homeostasis were assessed. Results indicated that strain A. aculeatus produced indole-3-acetic acid (IAA) and siderophores and exhibited a greater capacity for Na+ absorption under salt stress. The plant inoculation by A. aculeatus increased plant growth and attenuated the NaCl-induced lipid peroxidation in roots and leaves of bermudagrass. The fungus significantly elevated the amount of IAA and glutathione and slightly enhanced photosynthetic efficiency of salt-treated bermudagrass. Tissues of inoculated plants had significantly increased concentrations of K+ but lower Na+ concentrations than those of uninoculated regimes. It appears that the role of A. aculeatus in alleviating bermudagrass salt stress is partly to produce IAA, to increase the activity of antioxidases, to absorb Na+ by fungal hyphae, and to prevent the plant from ionic homeostasis disruption.

Infection and Colonization of Several Bermudagrasses by Ophiosphaerella korrae.

Bermudagrass (Cynodon spp.) is the most commonly used turfgrass in the southern United States where it is severely affected by spring dead spot (SDS) caused by Ophiosphaerella herpotricha, O. korrae, and O. narmari. In this study, infection of bermudagrass roots and stolons by O. korrae was characterized using a transformant that expressed the red fluorescent protein tdTomato. Roots of interspecific hybrid cultivars Midlawn and Tifway 419, C. transvaalensis accessions Uganda and 3200, and C. dactylon cultivar U3 were inoculated and observed from 2 to 14 days postinoculation (DPI) while stolons were observed from 2 to 22 DPI. For all five cultivars tested, a similar level of root colonization was observed; however, differences were observed in the rate of necrosis development. Necrosis of Tifway 419 and Midlawn tissues was evident at 2 DPI, in Uganda and 3200 at 8 DPI, and in U3 necrosis was often absent as late as 14 DPI. The fungus rapidly penetrated the root epidermis and colonized the cortex of all cultivars by 4 DPI. Colonization of stele tissues by O. korrae was rare in hybrid cultivars but common in C. transvaalensis and C. dactylon accessions. On intact stolons, the fungus did not penetrate the epidermis 22 DPI though epidermal necrosis was evident on the surface of only the hybrid bermudagrasses. Wounded stolons became necrotic in all cultivars. Infection and colonization of various bermudagrasses by O. korrae was found to be similar to that by O. herpotricha, suggesting that host genetic resistance may be used for effective management of SDS caused by both species.

Effect of microbial inoculants on the quality and aerobic stability of bermudagrass round-bale haylage.

The objective of this study was to compare the efficacy of using 4 commercially available microbial inoculants to improve the fermentation and aerobic stability of bermudagrass haylage. We hypothesized that the microbial inoculants would increase the fermentation and aerobic stability of the haylages. Bermudagrass (4-wk regrowth) was harvested and treated with (1) deionized water (control); (2) Buchneri 500 (B500; Lallemand Animal Nutrition, Milwaukee, WI) containing 1×10(5) of Pediococcus pentosaceus and 4×10(5) of Lactobacillus buchneri 40788; (3) Biotal Plus II (BPII; Lallemand Animal Nutrition) containing 1.2×10(5) of P. pentosaceus and Propionibacteria freudenreichii; (4) Silage Inoculant II (SI; AgriKing Inc., Fulton, IL) containing 1×10(5) of Lactobacillus plantarum and P. pentosaceus; and (5) Silo King (SK; AgriKing Inc.), containing 1×10(5) of L. plantarum, Enterococcus faecium, and P. pentosaceus, respectively. Forty round bales (8 per treatment; 441±26kg; 1.2×1.2 m diameter) were made and each was wrapped with 7 layers of plastic. Twenty bales were stored for 112 d and the remaining 20 were stored for 30 d and sampled by coring after intermediary storage periods of 0, 3, 7, and 30 d. The pH of control and inoculated haylages sampled on d 3 did not differ. However, B500 and BPII had lower pH (5.77±0.04 vs. 6.16±0.04; 5.06±0.13 vs. 5.52±0.13) than other treatments by d 7 and 30, respectively. At final bale opening on d 112, all treatments had lower pH than the control haylage (4.77±0.07 vs. 5.37±0.07). The B500, BPII, and SI haylages had greater lactic acid and lactic-to-acetic acid ratios than SK and control haylages. No differences were detected in neutral detergent fiber digestibility, dry matter losses, dry matter, lactic and acetic acid concentrations, and yeast and coliform counts. The SK haylage had lower clostridia counts compared with the control (1.19±0.23 vs. 1.99±0.23 cfu/g). Treatments B500, BPII, SI, and SK tended to reduce mold counts and they improved aerobic stability by 236, 197, 188, and 95%, respectively, compared with the control (276±22 vs. 99±22h).

Enhancing rice growth and yield with weed endophytic bacteria Alcaligenes faecalis and Metabacillus indicus under reduced chemical fertilization.

Endophytic bacteria, recognized as eco-friendly biofertilizers, have demonstrated the potential to enhance crop growth and yield. While the plant growth-promoting effects of endophytic bacteria have been extensively studied, the impact of weed endophytes remains less explored. In this study, we aimed to isolate endophytic bacteria from native weeds and assess their plant growth-promoting abilities in rice under varying chemical fertilization. The evaluation encompassed measurements of mineral phosphate and potash solubilization, as well as indole-3-acetic acid (IAA) production activity by the selected isolates. Two promising strains, tentatively identified as Alcaligenes faecalis (BTCP01) from Eleusine indica (Goose grass) and Metabacillus indicus (BTDR03) from Cynodon dactylon (Bermuda grass) based on 16S rRNA gene phylogeny, exhibited noteworthy phosphate and potassium solubilization activity, respectively. BTCP01 demonstrated superior phosphate solubilizing activity, while BTDR03 exhibited the highest potassium (K) solubilizing activity. Both isolates synthesized IAA in the presence of L-tryptophan, with the detection of nifH and ipdC genes in their genomes. Application of isolates BTCP01 and BTDR03 through root dipping and spraying at the flowering stage significantly enhanced the agronomic performance of rice variety CV. BRRI dhan29. Notably, combining both strains with 50% of recommended N, P, and K fertilizer doses led to a substantial increase in rice grain yields compared to control plants receiving 100% of recommended doses. Taken together, our results indicate that weed endophytic bacterial strains BTCP01 and BTDR03 hold promise as biofertilizers, potentially reducing the dependency on chemical fertilizers by up to 50%, thereby fostering sustainable rice production.

Water deficits shape the microbiome of Bermudagrass roots to be Actinobacteria rich.

There is increasing evidence that microbes can help ameliorate plant growth under environmental stress. Still, it is largely unknown what microbes and potential functions are involved in sustaining turfgrass, the major component of urban/suburban landscapes, under drought. We examined microbial responses to water deficits in bulk soil, rhizosphere, and root endosphere of bermudagrass by applying evapotranspiration (ET)-based dynamic irrigation twice per week during the growing season to create six treatments (0%, 40%, 60%, 80%, 100%, and 120% ET) and respective drought-stressed soil conditions. Bacterial and fungal communities were analyzed via marker gene amplicon sequencing and thereafter drought-reshaped potential functions of the bacterial community were projected. Slight yet significant microbial responses to irrigation treatments were observed in all three microhabitats. The root endophytic bacterial community was most responsive to water stress. No-irrigation primarily increased the relative abundance of root endophytic Actinobacteria, especially the genus Streptomyces. Irrigation at ≤40% ET increased the relative abundances of PICRUSt2-predicted functional genes encoding 1-aminocyclopropane-1-carboxylic acid deaminase, superoxide dismutase, and chitinase in root endosphere. Our data suggest that the root endophytic Actinobacteria are likely the key players to improve bermudagrass fitness under drought by modulating phytohormone ethylene production, scavenging reactive oxygen species, or ameliorating nutrient acquisition.

Evidence for functional divergence in arbuscular mycorrhizal fungi from contrasting climatic origins.

A considerable amount of phenotypic, genetic and symbiotic functional variability has been documented in arbuscular mycorrhizal fungi (AMF). However, little is known about whether distinct AMF ecotypes have evolved within their geographic range. We tested the hypothesis that AMF growing at temperatures closer to those prevalent within their origin would benefit their host and grow more than isolates distant from their native conditions. For each of six AMF species, we chose pairs of isolates that originated from distant areas with contrasting climates. Each isolate was grown in association with two grass species of different thermal optima at two temperature settings. Thus, we also tested whether AMF from different climatic origins were dependent on the thermal adaptation of the host plant species or to temperature per se. Although fungal growth was not directly affected by temperature, we found that AMF isolates originating from contrasting climates consistently and differentially altered plant growth. Our results suggest that AMF from contrasting climates have altered symbiotic function, thus linking an abiotic factor to ecotypic differentiation of putatively important symbionts.

The role of a plant/fungal consortium in the degradation of bituminous hard coal.

The sporadic growth of Cynodon dactylon was observed to occur directly on the surface of hard coal in dumps of the Witbank coal mining area of South Africa with the surface coal being broken down into a humic-like particulate material. Microorganism analysis of plants and rhizosphere material from the dumps revealed the presence of arbuscular mycorrhizal fungi and the coal solubilising fungus, Neosartorya fischeri. Studies established to replicate the dump environment revealed increased coal degradation in the form of humic acid production and an increase in small size particles as a result of Cynodon dactylon growth in association with arbuscular mycorrhizal fungi and Neosartorya fischeri. Results suggest that interactions between Cynodon dactylon, arbuscular mycorrhizal fungi, Neosartorya fischeri and other coal-degrading rhizosphere fungi could lead to the degradation of hard coal in situ and that the application of these organisms to discard dumps could be a novel method of coal dump rehabilitation.

Effective methane production from the Japanese weed Gyougi-shiba (Cynodon dactylon) is accomplished by colocalization of microbial communities that assimilate water-soluble and -insoluble fractions.

Weed, an abundant biomass, is considered unsuitable as a raw material for methane production. There are few reports on the anaerobic digestion of weeds without the addition of other organic wastes. To solve this problem, a methane-producing microbial community with weed as a sole feedstock was established. This study mainly focused on the degree of contribution between water-soluble and -insoluble fractions of the weed to methane production; thus, methane production from both fractions was tested separately. Methane production after 80-day batch cultures with whole weed, water-soluble and water-insoluble fractions was 184.5, 96.8 and 26.5 NmL g-1 dry matter (DM), respectively. The results of 16S rRNA gene amplicon sequence analysis revealed that Proteiniphilum saccharofermentans and several Methanobacterium species commonly dominated all cultures, whereas the population dynamics of minor species differed in every culture. Moreover, the remixed culture of microbial communities adapted to water-soluble and -insoluble fractions recovered methane production (252.4 NmL g-1 DM). Based on these results, it can be strongly inferred that colocalizing the minor species in water-soluble and -insoluble fractions is important for effective methane production.

Infection and colonization of turf-type bermudagrass by Ophiosphaerella herpotricha expressing green or red fluorescent proteins.

Spring dead spot, caused by Ophiosphaerella herpotricha, is the most important disease of turf-type bermudagrass (Cynodon spp.) in the transition zone of the United States. Despite the importance of the disease, only limited information is available about the host-pathogen interaction at the cellular level. To evaluate the host plant interaction, an isolate of O. herpotricha expressing green fluorescent proteins (GFP) or red fluorescent proteins (tdTomato) was used to study the infection and colonization of roots and stolons of several bermudagrass cultivars. Roots of cultivars Tifway 419 and Midlawn were colonized similarly, resulting in extensive root necrosis, whereas an accession of Cynodon transvaalensis was less necrotic. The stele of C. transvaalensis roots was colonized but not those of Tifway 419 and Midlawn. For intact stolons, colonization was limited to the epidermis and defined macroscopic necrotic lesions were observed on Tifway 419 and Midlawn while C. transvaalensis stolon tissues remained mostly nonnecrotic. Internal colonization of stolons occurred when hyphae grew into wounds, resulting in necrosis in Tifway 419 and Midlawn, but not in C. transvaalensis. These studies suggest that the interaction of O. herpotricha with bermudagrass varies across host genotypes and the host tissues infected. The limited necrosis in C. transvaalensis tissues, though colonized, suggests an inherent tolerance to O. herpotricha.

Seasonal Variation in Frequency of Isolation of Ophiosphaerella korrae from Bermudagrass Roots in Mississippi and Pathogenicity and Optimal Growth of Selected Isolates.

Isolation frequency of Ophiosphaerella korrae (spring dead spot pathogen) from Cynodon dactylon (bermudagrass) roots at a golf course near West Point, Mississippi, was monitored over a 3-year investigation. Laboratory and greenhouse experiments were conducted to determine optimal temperatures for the growth of selected O. korrae isolates collected from the field study and to evaluate those isolates for pathogenicity potential. Isolation frequencies of the pathogen from naturally infested root samples were significantly higher in the winter and spring and lowest in the fall regardless of cultural, nutrient, and chemical treatments. Annual soil temperatures ranged between 8 and 29 degrees C, and no correlation was observed between temperature and percent isolation of O. korrae. Optimal in vitro growth of selected O. korrae isolates ranged from 21 to 25 degrees C. Root discoloration was significantly greater in the presence of O. korrae compared to non-inoculated roots in greenhouse studies. Results of this study confirm and are the first to document that O. korrae naturally infests roots throughout the bermudagrass growth cycle, but factors other than temperature and management practices may influence O. korrae in situ.

Bioactive alkaloids from endophytic Aspergillus fumigatus.

Two new alkaloids, named 9-deacetylfumigaclavine C (1) and 9-deacetoxyfumigaclavine C (2), along with 12 known compounds (3-14), were isolated from the culture of Aspergillus fumigatus. The structures of the new compounds were elucidated by comprehensive spectroscopic analyses. Compound 2 showed selectively potent cytotoxicity against human leukemia cells (K562) with an IC(50) value of 3.1 microM, which was comparable to that of doxorubicin hydrochloride, a presently prescribed drug for the treatment of leukemia. Furthermore, 14-norpseurotin (4) significantly induced neurite outgrowth of rat pheochromocytoma cells (PC12) at a 10.0 microM concentration.

Recovery of Salmonella from bermudagrass exposed to simulated wastewater.

Most confined swine (Sus scrofa) feeding operations in the southeastern United States hold manure in lagoons and apply effluent on bermudagrass [Cynodon dactylon (L.) Pers.] as fertilizer. Salmonella enterica subsp. enterica (ex Kauffman and Edwards) Le Minor and Popoff, has been reported in Mississippi lagoons, but levels and potential for contamination of bermudagrass were unknown. A laboratory method was developed to examine Salmonella contamination of bermudagrass and levels of Salmonella were determined in lagoons. The U.S. Environmental Protection Agency (EPA) worst case water was used to simulate effluent in exposing bermudagrass to Salmonella. Exposed leaves were washed and bacteria enumerated. Contamination of leaves exposed to 10(6) cfu mL(-1) varied from 0 to 10(4) cfu per leaf within and among eight bermudagrass cultivars and five Salmonella isolates. No differences (P < 0.05) occurred between cultivars (n = 20) or isolates (n = 10). Data fitted (R2 = 0.93) to a contamination equation (y = 5 x 10(-6)X6.623) described the relationship between levels (Log10 cfu mL(-1)) of exposure (x) and contamination (y). In fall 2007 Salmonella levels from six lagoons ranged from 1.9 to 2.8 log10 MPN 100 mL(-1) and were below the threshold for contamination predicted by the equation. These preliminary results must be tested with effluents in the field, but considered alongside work of others, which report lagoon Salmonella levels to be highest in fall, suggest that Salmonella levels in effluents from these lagoons may be too low to produce measurable contamination on bermudagrass.

Rhizobacterial treatments of tall fescue and bermudagrass increases tolerance to damage from white grubs.

BACKGROUND: Inoculation of hybrid bermudagrass with plant growth-promoting rhizobacteria (PGPR) can increase plant growth and influence relationships with above-ground herbivores like fall armyworms. However, few experiments have evaluated PGPR applications relative to root herbivory. Root-feeding white grubs cause severe damage to grasses, especially in tall fescue pastures, golf courses, and lawns. Since bacterial inoculants enhance root growth, the goal of this study was to determine if the inoculation of hybrid bermudagrass by rhizobacteria can increase the tolerance of tall fescue and hybrid bermudagrass to damage from white grub feeding, and if PGPR are compatible with neonicotinoid insecticides commonly used for white grub control. RESULTS: In trials with tall fescue and hybrid bermudagrass, grasses were treated with the PGPR strain mixture Blend 20 or nitrogen or left non-treated and were then infested with Japanese beetle grubs. Grasses treated with PGPR and nitrogen fertilizer produced significantly more top growth than the non-treated grub-infested controls. Tall fescue and hybrid bermudagrass treated with Blend 20 produced root mass similar to or greater than nitrogen fertilized grasses. Both grasses treated with Blend 20 had greater root mass than non-treated infested grass. No treatment negatively impacted grub survival, and weight gains of grubs were similar for all treatments. Bacterial strains were typically compatible with insecticides used to control white grubs. CONCLUSION: PGPR and nitrogen fertilization stimulate root growth resulting in tolerance of tall fescue and hybrid bermudagrass to white grub infestation. PGPR, acting as biostimulants to increase root biomass on grasses, may have utility for IPM of root herbivores. © 2019 Society of Chemical Industry.

Toxic effects of chlorate on three plant species inoculated with arbuscular mycorrhizal fungi.

Pot experiments were conducted to examine the toxic effects of chlorate on bermudagrass, bahiagrass, and longan seedling with a focus on arbuscular mycorrhizal fungi-plant associations. The results show that application of chlorate could cause slight soil acidification, but the resulting pH was still around 5.5, which is unlikely to adversely affect plant growth. Increase in the application rate of chlorate resulted in a decrease in colonization rate of arbuscular mycorrhizal fungi in plant roots, P uptake by the plants and plant biomass. This appears to suggest that the reduction in plant growth may be related to impeded uptake of P by the plants due to the failure of the plants to form sufficient mycorrhizal associations when chlorate is in sufficient amounts to cause toxicity to arbuscular mycorrhizal fungi. Under the experimental conditions set for this study, bermudagrass suffered from stronger chlorate stress than bahiagrass and longan seedling did in terms of plant-arbuscular mycorrhizal fungi (AMF) symbiosis development.

[Association of phytoplasma with Bermuda grass white-leaf disease].

OBJECTIVE: Bermuda grass white leaf is an important disease on Bermuda grass all over the world. The aim of this research is to identify the pathogen which leads to Bermuda grass white leaf occurring on the Chinese mainland. METHODS: PCR amplification technique, sequence analysis and Southern hybridization were used. RESULTS: A 1.3 kb fragment was amplified by PCR phytoplasma universal primers and total DNA sample extracted from ill Bermuda grass as the amplified template. Sequence analysis of the amplified fragment indicated it clustered into Candidatus Phytoplasm Cynodontis. Southern hybridization analysis showed differential cingulums. CONCLUSION: The pathogen of Bermuda grass white leaf on the Chinese mainland contains phytoplasma, which provides a scientific basis for further identification, prevention and control of the disease.

Bacterial Inoculant Treatment of Bermudagrass Alters Ovipositional Behavior, Larval and Pupal Weights of the Fall Armyworm (Lepidoptera: Noctuidae).

Nonpathogenic soil bacteria can colonize the rhizosphere and induce unique plant phenotypes that may influence plant-insect interactions. However, few studies have considered the influences of bacteria-plant interactions on insect feeding and oviposition. The objective of this study was to determine how rhizobacterial inoculation of bermudagrass affects larval development and ovipositional behaviors of the fall armyworm (Spodoptera frugiperda J.E. Smith). Eight blends of rhizobacteria known to induce root or shoot growth in grasses were applied weekly to hybrid bermudagrass for 5 wk. Oviposition was evaluated in two no-choice trials with bacteria-treated, fertilized, or nontreated grass. Grass blades from these treatments were extracted in polar and nonpolar solvents and assayed for oviposition responses. Another experiment compared the development of fall armyworm larvae on bermudagrass treated with each of the eight rhizobacterial blends for 5 wk to larvae fed nontreated bermudagrass. Females deposited more eggs on nontreated and fertilized grass and ≤34% of eggs on grass treated with rhizobacterial blends. Moths exposed to polar and nonpolar extracts were unable to reproduce these results. Larval and pupal weights at days 10 and 12 and the number of adults to eclose were lower for larvae fed some, but not all, bacteria-treated bermudagrass relative to controls. This is one of the few studies to investigate plant-microbe-insect interactions in an economically important system. Although the effects noted with fall armyworm are limited, induced changes in roots also reported for these bacteria may have greater utility than foliar changes for mediating interactions with biotic or abiotic stresses.

Effects of cadmium-resistant fungi Aspergillus aculeatus on metabolic profiles of bermudagrass [Cynodondactylon (L.)Pers.] under Cd stress.

Plants' tolerance to heavy metal stress may be induced by the exploitation of microbes. The objectives of this study were to investigate the effect of cadmium (Cd)-resistant fungus, Aspergillus aculeatus, on tolerance to Cd and alteration of metabolites in bermudagrass under Cd stress, and identify the predominant metabolites associated with Cd tolerance. Two genotypes of bermudagrass with contrasting Cd tolerance (Cd-sensitive 'WB92' and Cd-tolerant 'WB242') were exposed to 0, 50, 150 and 250 mg kg-1 Cd for 21 days. Physiological responses of bermudagrass to Cd stress were evaluated based on the relative growth rate (RGR) and normalized relative transpiration rate (NRT). Plants inoculated with A. aculeatus exhibited higher RGR and NRT under Cd stress than those of non-inoculated plants, regardless of genotypes. A total of 32 Cd-responsive metabolites in leaves and 21 in roots were identified in the two genotypes, including organic acids, amino acids, sugars, and fatty acids and others. Interestingly, under Cd stress, the leaves of inoculated 'WB92' accumulated less citric acid, aspartic acid, glutamic acid, sucrose, galactose, but more sorbose and glucose, while inoculated 'WB242' leaves had less citric acid, malic acid, sucrose, sorbose, but more fructose and glucose, compared to non-inoculated plants. In 'WB92' roots, the A. aculeatus reduced mannose content, but increased trehalose and citric acid content, while in 'WB242', it decreased sucrose, but enhanced citric acid content, compared to Cd regime. The results of this study suggest that A. aculeatus may induce accumulation of different metabolites associated with Cd tolerance in bermudagrass.