Mycorrhizal Species Research Articles

Unravelling the distribution of mycorrhizal plants in the Colombian páramos

AbstractThe tropicalpine páramo stands out as a unique biodiversity hotspot located in the northern Andes. Over the last decades, páramo plants and animals have been increasingly studied, yet a critical knowledge gap remains on their microbial ecology. Given the crucial importance of mycorrhiza in structural and functional communities, our study aimed to explore their geographic distribution in the Colombian páramos. Specifically, we used information about their host plants as a proxy and modelled their current distribution to unravel spatial patterns related to mycorrhizal status and mycorrhizal types. We constructed species distribution models for 440 vascular plant species representatives of the Colombian páramos using a combination of climatic and edaphic variables. Then we stacked the models following species classification into their mycorrhizal type: arbuscular, ectomycorrhizal, ericoid, orchid, and non-mycorrhizal. Our results suggest that the abundance of mycorrhizal species decreases with increasing elevation and in the west-to-east direction. The arbuscular type of mycorrhiza is chiefly dominant and spreads out widely throughout the Colombian páramos. The other types showed singular patterns, with (i) species having ericoid mycorrhiza being abundant in both the southern (Nariño–Putumayo) and the northern páramos (Sierra Nevada–Perijá); (ii) species with orchid mycorrhiza being abundant in the Western Cordillera and overall at low elevations, (iii) ectomycorrhizal species being absent, and (iv) non-mycorrhizal species being widely spread and reaching high elevations. Our study highlights the potentially high level of mycorrhization of this alpine system and contributes new spatial and environmental information towards a better understanding of mycorrhizal biogeography in tropical mountains.

Independent effects of tree diversity on aboveground and soil carbon pools after six years of experimental afforestation.

Planting diverse forests has been proposed as a means to increase long-term carbon (C) sequestration while providing many co-benefits. Positive tree diversity-productivity relationships are well established, suggesting more diverse forests will lead to greater aboveground C sequestration. However, the effects of tree diversity on belowground C storage have the potential to either complement or offset aboveground gains, especially during early stages of afforestation when potential exists for large losses in soil C due to soil decomposition. Thus, experimental tests of the effects of planted tree biodiversity on changes in whole-ecosystem C balance are needed. Here, we present changes in above- and belowground C pools 6 years after the initiation of the Forests and Biodiversity experiment (FAB1), consisting of high-density plots of one, two, five, or 12 tree species planted in a common garden. The trees included a diverse range of native species, including both needle-leaf conifer and broadleaf angiosperm species, and both ectomycorrhizal and arbuscular mycorrhizal species. We quantified the effects of species richness, phylogenetic diversity, and functional diversity on aboveground woody C, as well as on mineral soil C accumulation, fine root C, and soil aggregation. Surprisingly, changes in aboveground woody C pools were uncorrelated to changes in mineral soil C pools, suggesting that variation in soil C accumulation was not driven by the quantity of plant litter inputs. Aboveground woody C accumulation was strongly driven by species and functional identity; however, plots with higher species richness and functional diversity accumulated more C in aboveground wood than expected based on monocultures. We also found weak but significant effects of tree species richness, identity, and mycorrhizal type on soil C accumulation. To assess the role of the microbial community in mediating these effects, we further compared changes in soil C pools to phospholipid fatty acid (PLFA) profiles. Soil C pools and accumulation were more strongly correlated with specific microbial clades than with total microbial biomass or plant diversity. Our results highlight rapidly emerging and microbially mediated effects of tree biodiversity on soil C storage in the early years of afforestation that are independent of gains in aboveground woody biomass.

Influence of arbuscular mycorrhizal species on total dry matter accumulation, yield and its attributes of groundnut under water stress

Influence of arbuscular mycorrhizal species on total dry matter accumulation, yield and its attributes of groundnut under water stress

Mycorrhizal Symbiosis Increases Plant Phylogenetic Diversity and Regulates Community Assembly in Grasslands.

The intricate mechanisms controlling plant diversity and community composition are cornerstone of ecological understanding. Yet, the role of mycorrhizal symbiosis in influencing community composition has often been underestimated. Here, we use extensive species survey data from 1315 grassland sites in China to elucidate the influence of mycorrhizal symbiosis on plant phylogenetic diversity and community assembly. We show that increasing mycorrhizal symbiotic potential leads to greater phylogenetic dispersion within plant communities. Mycorrhizal species predominantly influence deterministic processes, suggesting a role in niche-based community assembly. Conversely, non-mycorrhizal species exert a stronger influence on stochastic processes, highlighting the importance of random events in shaping community structure. These results underscore the crucial but often hidden role of mycorrhizal symbiosis in driving plant community diversity and assembly. This study provides valuable insights into the mechanisms shaping ecological communities and the way for more informed conservation that acknowledges the complex interplay between symbiosis and community dynamics.

Large wildfires alter the potential capacity of fire-prone Mediterranean pine forests to provide wild edible mushrooms over the long term

Projected trends of intensified wildfires due to climate warming and fuel-load accumulation are expected to significantly alter fungal diversity, but we know little about how these changes will impact ecosystem services. We aimed to analyze how large wildfires alter the capacity of fire-prone Mediterranean ecosystems dominated by Pinus pinaster Ait. to deliver the provisioning ecosystem service of mushroom production throughout the post-fire succession. We assessed this at early (<10 years), medium (10-20 years), and late (>20 years) stages after fire, compared to an unburned forest. Our results evidenced that large wildfires significantly reduced the capacity of these forests to provide mushroom harvesting opportunities. This adverse effect was most pronounced in the first few years after wildfire but persisted even after 20 years of post-fire succession. The total fungal species richness, abundance, diversity, and productivity at the post-fire successional stages remained lower than in the unburned forest, failing to reach their pre-fire levels even after two decades. However, the presence of commercially valuable edible fungal species, along with their species richness and productivity, began to recover in the medium and late stages after fire. In the immediate aftermath of the fire, saprotrophic fungal species dominated, while mycorrhizal species became more prevalent during the medium and late stages of secondary succession. Additionally, the abundance and productivity of mycorrhizal species in the late succession stage approached those found in the unburned forest. Soil pH and biochemical variables (microbial biomass C and β-glucosidase enzymatic activity) were key drivers of changes in species composition along the successional stages. This knowledge is essential to guide management solutions aimed at reducing ecosystem service loss and increasing resilience to the new scenario of extreme large wildfire events at shorter fire-free intervals, especially in southern Europe.

Is a combination of arbuscular mycorrhizal fungi more beneficial to enhance drought tolerance than single arbuscular mycorrhizal fungus in Lallemantia species?

Climate change-induced abiotic stress hinders crop growth, providing a challenge to global food security and agricultural sustainability. An effective approach to safeguard crop production from drought stress is to use either a single species or co-inoculating different native arbuscular mycorrhizal fungi (AMF) species. A pot experiment was carried out to examine the impacts of using single and combined AMF (Claroideoglomus etunicatum, Funneliformis mosseae, and Rhizophagus intraradices) on the growth and physiological-biochemical characteristics of Lallemantia species (Lallemantia iberica and L. royleana) under well-watered, moderate drought, and severe drought conditions. Drought stress had a notable negative impact on growth performance, photosynthetic rate, antioxidant enzyme activities, water use efficiency, nutrient uptake, oil and fatty acid levels, and sugar components, which were associated with restricted root development. In contrast, inoculation with mycorrhizal species, especially Mix 4 treatment (C. etunicatum, F. mosseae, and R. intraradices), significantly boosted root AMF colonization, leading to an increase in mycorrhizal growth response, mycorrhizal dependency, water use efficiency, and seed yield. Seeds produced under Mix 4 inoculation showed the highest levels of mucilage, sugar compounds, oil, and fatty acid compositions, compared with individual AMF and other AMF mixtures. Furthermore, the presence of hydrogen peroxide and lipid peroxidation was significantly reduced by applying Mix 4 treatment under drought stress. It suggested that a combination of AMF species can better promote the growth and yield of Lallemantia species during drought stress by preserving the plants' physiological functions than single arbuscular mycorrhizal fungus.

Impact of three distinct mycorrhizal species on Cedrus libani seedling development and nutrient uptake

Aim of study: In semi-arid afforestation sites, the study aimed to create mycorrhizal seedlings with high vitality, health, and tolerance to harsh environments. The study's hypotheses state that mycorrhizal inoculation will improve Cedrus libani (Taurus cedar) seedlings' growth characteristics, nutrition, root colonization, and mycorrhizal reliance. Area of study: The Eastern Mediterranean Research Institute laboratory and greenhouse in Tarsus district-Mersin, Türkiye. Material and methods: The experiment involved inoculation of three ectomycorrhizal fungal species (Lactarius delicious, Hebeloma crustuliniforme, Tricholoma ustale) collected from natural cedar stands on to cedar seedlings grown in two different substrates (sterilized, non-sterilized. Inoculation was carried out by dipping the roots of Cedrus libani A. Rich (Taurus cedar) seedlings into mycorrhizal mycelia. Main results: Cedar seedlings infected with mycorrhiza exhibited a greater biomass ratio in comparison to the control seedlings. Substrate sterilization increased seedling growth variables. The highest growth, some nutrients such as N, P, K, Fe and Zn uptake, root colonization and mycorrhizal dependence occurred in seedlings with H. crustuliniforme and L. delicious. Research highlights: Although this study is limited to Taurus cedar-mycorrhiza combinations, it may also be applicable to different mycorrhizal fungal species and many other valuable host tree species. More research is needed on the adaptation of different mycorrhizal species to habitats to increase the success of afforestation efforts in arid and semi-arid regions.

Phylogenetic Assessment of Understudied Families in Hymenochaetales (Basidiomycota, Fungi)—Reporting Uncovered Species and Reflecting the Recent Taxonomic Updates in the Republic of Korea

Hymenochaetales Oberw. is an order classified in Basidiomycota of Fungi, and species in this order display notable diversity. They exhibit various fruiting body shapes, including clavarioid, effused-reflexed, and resupinate basidiomes. Few mycorrhizal species have been reported in Hymenochaetales, but wood-decaying species dominate the order. Hymenochaetaceae Imazeki & Toki and Schizoporaceae Jülich are the most species-rich families within Hymenochaetales, and most species in the Republic of Korea belong to these two families. As such, current taxonomic classification and nomenclature are not reflected upon species in the remaining Hymenochaetales families. For this study, a multifaceted morphological and multigenetic marker-based phylogenetic investigation was conducted to, firstly, comprehensively identify understudied Hymenochaetales specimens in Korea and, secondly, reflect the updates on the species classification. Five genetic markers were assessed for the phylogenetic analysis: nuclear small subunit ribosomal DNA (nSSU), internal transcribed spacer (ITS), nuclear large subunit ribosomal DNA (nLSU), RNA polymerase II subunit 2 gene (RPB2), and translation elongation factor 1 gene (TEF1). The results from phylogenetic analysis supported 18 species classified under eight families (excluding Hymenochaetaceae and Schizoporaceae) in Korea. Species formerly placed in Rickenellaceae and Trichaptum sensu lato have been systematically revised based on recent taxonomic reconstructions. In addition, our findings revealed one new species, Rickenella umbelliformis, and identified five formerly nationally unreported species classified under five understudied families. Our findings contribute to a better understanding of Hymenochaetales diversity and highlight the need for continued research.

Nutritional contents and antimicrobial activity of the culinary-medicinal mushroom Leccinum scabrum

ABSTRACT Leccinum scabrum (Bull.) Gray (Boletaceae) is an edible mycorrhizal species with potential application interest due to its food and medicinal properties. A field investigation carried out during summer in the Białowieża Primeval Forest, located along the border between Belarus and Poland allowed to collect samples for chemical composition analysis and antibacterial activity evaluation. Mushroom extracts were prepared with microwave-assisted as well as ultrasound-assisted extraction techniques (UAE and MAE). The analysis of a dry sample of L. scabrum showed a significant content of vitamins and minerals and also a remarkable content of carbohydrates, protein, dietary fibre, total sugars, total free amino acids, and polyunsaturated fatty acids. The antibacterial activity of L. scabrum aqueous extracts showed inhibitory activity against all tested bacteria. In general, MAE extract exhibits a higher inhibition activity against Listeria monocytogenes ATCC 19114. As regards the Minimum Inhibitory Concentration (MIC) values, the high antibacterial activity of MAE extract was detected for L. monocytogenes ATCC 19114 and Escherichia coli ATCC 25922. Regarding UAE, high antibacterial activity was detected for Salmonella enterica ATCC 13076 and L. monocytogenes ATCC 19114. Based on data hereby reported, L. scabrum is a culinary-medicinal mushroom with a promising potential use as a high-quality food and nutraceutical mycological resource.

Mycorrhiza-induced resistance in citrus against Tetranychus urticae is plant species dependent and inversely correlated to basal immunity.

Mycorrhizal plants show enhanced resistance to biotic stresses, but few studies have addressed mycorrhiza-induced resistance (MIR) against biotic challenges in woody plants, particularly citrus. Here we present a comparative study of two citrus species, Citrus aurantium, which is resistant to Tetranychus urticae, and Citrus reshni, which is highly susceptible to T. urticae. Although both mycorrhizal species are protected in locally infested leaves, they show very distinct responses to MIR. Previous studies have indicated that C. aurantium is insensitive to MIR in systemic tissues and MIR-triggered antixenosis. Conversely, C. reshni is highly responsive to MIR which triggers local, systemic and indirect defense, and antixenosis against the pest. Transcriptional, hormonal and inhibition assays in C. reshni indicated the regulation of jasmonic acid (JA)- and abscisic acid-dependent responses in MIR. The phytohormone jasmonic acid isoleucine (JA-Ile) and the JA biosynthesis gene LOX2 are primed at early timepoints. Evidence indicates a metabolic flux from phenylpropanoids to specific flavones that are primed at 24 h post infestation (hpi). MIR also triggers the priming of naringenin in mycorrhizal C. reshni, which shows a strong correlation with several flavones and JA-Ile that over-accumulate in mycorrhizal plants. Treatment with an inhibitor of phenylpropanoid biosynthesis C4H enzyme impaired resistance and reduced the symbiosis, demonstrating that phenylpropanoids and derivatives mediate MIR in C. reshni. MIR's effectiveness is inversely correlated to basal immunity in different citrus species, and provides multifaceted protection against T. urticae in susceptible C. reshni, activating rapid local and systemic defenses that are mainly regulated by the accumulation of specific flavones and priming of JA-dependent responses. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Arbuscular mycorrhizal fungi induce Zn uptake and antioxidant efficiency in broccoli (Brassica oleracea L.) exposed to Zn deficiency

Zinc (Zn) is an essential micronutrient for plant growth and development, and its deficiency in soil can be a significant problem for broccoli (Brassica oleracea L.) production. While the genetic efforts to breed Zn-efficient broccoli are complex, harnessing microbiomes is an emerging way to induce mineral efficiency in crops. In this study, broccoli, a non-host mycorrhizal species, was cultivated with or without zinc deficiency in the presence or absence of arbuscular mycorrhizal fungi (AMF), confirmed by the colonization efficiency in roots. Zn deficiency caused a significant decrease in morphological parameters and photosynthetic attributes being consistent with the decreased Zn levels in root and shoot relative to Zn-sufficient plants. However, the broccoli plants inoculated with AMF showed a substantial improvement in morphological and photosynthetic parameters in Zn-deficient conditions due to the significant increase in tissue Zn levels. In addition, AMF-inoculated plants under Zn deficiency showed a significant decrease in cell death (%), electrolyte leakage, and H2O2 levels compared to Zn-deficient plants, which further suggests the improvements in cellular status due to the AMF colonization. The real-time PCR experiments showed a significant induction in the expression of BoZIP1 and BoNRAMP1 genes in the roots of Zn-deficient broccoli inoculated with AMF, suggesting that AMF may be associated with the induction of these genes responsible for Zn-uptake and transport. We further observed the induction of POD (peroxidase), APX (ascorbate peroxidase) and SOD (superoxide dismutase), and S-metabolites (cysteine and glutathione) predominantly in the roots of Zn-starved broccoli inoculated with AMF which may confer tolerance to Zn-deficiency induced oxidative damage. This is the first report on the role of AMF in mitigating Zn-deficiency in broccoli which may promote the microbiome-aided improvement in plant health suffering from Zn-deficiency in broccoli and other vegetable crops.

Resilience to summer bushfire in the threatened orchid, Caladenia tessellata, in terms of pollination success, herbivory, and mycorrhizal associations

Abstract In some biogeographic regions, many threatened plant species occur in habitats that periodically experience bushfire. However, we currently have relatively little information on how important plant–animal and plant–fungus interactions are affected by these fires. For the threatened sexually deceptive orchid Caladenia tessellata we test whether pollination rate, frequency of florivory, and the species of mycorrhizae the plant associates with differ between burnt and unburnt sites. Interestingly, pollination rates were unaffected by fire, demonstrating that populations of the thynnine wasp pollinator can persist post-fire. However, there was a significant negative relationship between number of flowers in a population and pollination success, which is likely a by-product of a deceptive pollination strategy. Despite the presence of vertebrate herbivores, florivory rates were low in both burnt and unburnt sites. Caladenia tessellata associated primarily with the mycorrhiza Serendiptia australiana, regardless of fire history. While our results suggest resilience to a one-off summer fire for the ecological interactions that we measured, it would be interesting to investigate the effects of fire frequency and time of year. High reproductive rates in small populations of C. tessellata suggest these populations may be viable and that retaining them is a high priority for conservation.

Mitigating the effects of water-deficit stress on potato growth and photosynthesis using mycorrhizal fungi and phosphate-solubilizing bacteria

AbstractBiofertilizers, such as arbuscular mycorrhiza fungi and phosphate-solubilizing bacteria (PSB), have been reported to enhance plant growth under water stress conditions. This study aimed to investigate the effect of different biofertilizers on potato photosynthesis and growth under water deficit stress. The experiment was conducted over two crop years (2019 and 2020) using a randomized complete block design with three replications. Four irrigation intervals (70, 90, 110 and 130 mm of cumulative evaporation) and six biofertilizer treatments (PSB, Funneliformis mosseae [FM], Rhizoglomus fasciculatum [RF], PSB + FM, PSB + RF and no use) were applied. Severe moisture stress (130 mm evaporation) compared to no stress (70 mm evaporation) increased substomatal carbon dioxide concentration. The application of biofertilizers improved tuber yield under severe moisture stress, with FM showing the highest increase (62.9%), followed by RF (59.8%) and PSB (48.4%). The use of PSB along with mycorrhizae led to a significant decrease in mycorrhizal colonization percentage at all irrigation levels. The highest percentage of colonization and net photosynthesis was obtained from the application of both mycorrhizal species under irrigation conditions after 70 mm of evaporation. The application of PSB alone resulted in a 14.6% increase in the transpiration rate, additionally, the use of mycorrhiza led to an 18.7% increase in stomatal conductivity compared to no-biofertilizer. The results suggest that the simultaneous use of PSB and mycorrhizae can be effective in mild moisture stress, but in severe moisture stress, the use of mycorrhizal species alone is more effective.

Forest tree community ecology and plant–soil feedback: Theory and evidence

AbstractMounting evidence suggests that reciprocal interactions between plants and the soil microbiota can be a primary force that generates key macroscopic patterns of plant communities (coexistence, dominance, and succession) in forest ecosystems. The aim of this article is to review empirical and theoretical perspectives of plant–soil feedback research in the context of forest community ecology. I first use a simple theoretical model to get insights into an array of the dynamics generated by plant–soil feedback: negative plant–soil feedback maintains plant species diversity and reduces plant growth, while positive plant–soil feedback drives plant growth of certain species and hence their dominance. I then describe how ecologists have unveiled the enormously complex plant‐microbiota interaction (i.e., the soil conditioning experiment) and review the linkage of plant–soil feedback with three key plant community patterns: (i) dominance, (ii) spatial structure and (iii) succession. I highlight one belowground plant trait (mycorrhizal type) that can mediate these linkages: arbuscular mycorrhizal species tend to exhibit negative plant–soil feedback while ectomycorrhizal species tend to exhibit positive plant–soil feedback. Although mycorrhizal plant–soil feedback potentially explains the patterns of tree diversity from local to global scales, many questions remain. Future studies should expand plant–soil feedback theory to incorporate numerous other feedback mechanisms and test how mycorrhizal types mediate the net feedback effects that could propagate to shape large‐scale forest structures and dynamics.

Verification study on how macrofungal fruitbody formation can be predicted by artificial neural network

The occurrence and regularity of macrofungal fruitbody formation are influenced by meteorological conditions; however, there is a scarcity of data about the use of machine-learning techniques to estimate their occurrence based on meteorological indicators. Therefore, we employed an artificial neural network (ANN) to forecast fruitbody occurrence in mycorrhizal species of Russula and Amanita, utilizing meteorological factors and validating the accuracy of the forecast of fruitbody formation. Fungal data were collected from two locations in Western Hungary between 2015 and 2020. The ANN was the commonly used algorithm for classification problems: feed-forward multilayer perceptrons with a backpropagation algorithm to estimate the binary (Yes/No) classification of fruitbody appearance in natural and undisturbed forests. The verification indices resulted in two outcomes: however, development is most often studied by genus level, we established a more successful, new model per species. Furthermore, the algorithm is able to successfully estimate fruitbody formations with medium to high accuracy (60–80%). Therefore, this work was the first to reliably utilise the ANN approach of estimating fruitbody occurrence based on meteorological parameters of mycorrhizal specified with an extended vegetation period. These findings can assist in field mycological investigations that utilize sporocarp occurrences to ascertain species abundance.

Differential phosphorus acquisition strategies of nine cover crop species grown in a calcareous and a decalcified chernozem

Background and aimsCover cropping is a strategy to increase soil phosphorus (P) use efficiency in agroecosystems. We investigated adaptations on P acquisition strategies of nine cover crops grown in a calcareous and a non-calcareous chernozem with low available P.MethodsThrough a 108-day pot experiment using a calcareous and a decalcified chernozem, we evaluated black oat (Avena strigosa Schreb.), white lupin (Lupinus albus L.), narrow-leaf lupin (Lupinus angustifolius L.), phacelia (Phacelia tanacetifolia Benth.), berseem clover (Trifolium alexandrinum L.), buckwheat (Fagopyrum esculentum Moench), linseed (Linum usitatissimum L.), ramtil (Guizotia abyssinica [Lf] Cass.) and white mustard (Sinapis alba L.) for their dry biomass production, tissue P concentration and uptake, and effects on soil pH, phosphatase activity, mycorrhiza infection rate and soil P fractions.ResultsCover crops differed in several parameters between the two soils. Dry biomass varied from 3.3 (white lupin) to 41.6 g pot-1 (mustard). Tissue P concentrations ranged from 0.046% (mustard) to 0.24% (clover). Species affected pH of both soils, ranging from − 0.66 to + 0.24. Acid phosphatase activity was higher in the decalcified soil, while alkaline phosphatases were higher in the calcareous soil. Root mycorrhizal infection rates ranged from 0 to > 50%. Most plants explored soil labile P exclusively, with organic P mineralization being more relevant in the calcareous soil.ConclusionWe confirm that cover crops favoured distinct strategies to access the predominant soil labile P forms in each soil. Mycorrhizal species were particularly efficient in the decalcified soil, while species with high phosphatase secretion accessed higher Po, especially in the calcareous soil.

Mycorrhizal symbioses in the Andean paramo.

The Andean paramo, hereafter "paramo", is a Neotropical high-mountain region between the treeline and permanent snowline (3500-4800m) and is considered the world's coolest biodiversity hotspot. Because of paramo's high humidity, solar radiation and temperature variation, mycorrhizal symbiosis is expected to be essential for plants. Existing theory suggests that replacement of arbuscular mycorrhizal (AM) by ectomycorrhizal (ECM) and then ericoid mycorrhizal plants (ERM) can be expected with increasing elevation. Previous findings also suggest that non-(NM) and facultatively mycorrhizal (FM) species predominate over obligatory mycorrhizal (OM) species at high elevations. However, these expectations have never been tested outside of the northern temperate zone. We addressed the distribution and environmental drivers of plant mycorrhizal types (AM, ECM and ERM) and statuses (NM, FM and OM) along the paramo's elevational gradient. We used vegetation plots from the VegParamo database, climatic and edaphic data from online repositories, and up-to-date observation information about plant mycorrhizal traits at species and genus level, the latter being proposed as hypotheses. AM plants were dominant along the entire gradient, and ERM plants were most abundant at the lowest elevations (2500-3000m). The share of FM plants increased and that of OM plants decreased with elevation, while NM plants increased above 4000m. Temperature and soil pH were positively related to the abundance of AM plants and negatively to ERM plants. Our results reveal patterns that contrast with those observed in temperate northern-hemisphere ecosystems.

Tree mycorrhizal type regulates leaf and needle microbial communities, affects microbial assembly and co-occurrence network patterns, and influences litter decomposition rates in temperate forest

BackgroundTree mycorrhizal types (arbuscular mycorrhizal fungi and ectomycorrhizal fungi) alter nutrient use traits and leaf physicochemical properties and, thus, affect leaf litter decomposition. However, little is known about how different tree mycorrhizal species affect the microbial diversity, community composition, function, and community assembly processes that govern leaf litter-dwelling microbes during leaf litter decomposition. MethodsIn this study, we investigated the microbial diversity, community dynamics, and community assembly processes of nine temperate tree species using high-resolution molecular technique (Illumina sequencing), including broadleaved arbuscular mycorrhizal, broadleaved ectomycorrhizal, and coniferous ectomycorrhizal tree types, during leaf litter decomposition.Results and discussionThe leaves and needles of different tree mycorrhizal types significantly affected the microbial richness and community composition during leaf litter decomposition. Leaf litter mass loss was related to higher sequence reads of a few bacterial functional groups, particularly N-fixing bacteria. Furthermore, a link between bacterial and fungal community composition and hydrolytic and/or oxidative enzyme activity was found. The microbial communities in the leaf litter of different tree mycorrhizal types were governed by different proportions of determinism and stochasticity, which changed throughout litter decomposition. Specifically, determinism (mainly variable selection) controlling bacterial community composition increased over time. In contrast, stochasticity (mainly ecological drift) increasingly governed fungal community composition. Finally, the co-occurrence network analysis showed greater competition between bacteria and fungi in the early stages of litter decomposition and revealed a contrasting pattern between mycorrhizal types.ConclusionOverall, we conclude that tree mycorrhizal types influence leaf litter quality, which affects microbial richness and community composition, and thus, leaf litter decomposition.

Enhancing the Yield, Quality and Antioxidant Content of Lettuce through Innovative and Eco-Friendly Biofertilizer Practices in Hydroponics

Hydroponics is a contemporary agricultural system providing precise control over growing conditions, potentially enhancing productivity. Biofertilizers are environmentally friendly, next-generation fertilizers that augment product yield and quality in hydroponic cultivation. In this study, we investigated the effect of three bio-fertilizers in a hydroponic floating system, microalgae, plant growth-promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF), combined with a 50% reduction in mineral fertilizer, on lettuce yield and quality parameters including antioxidants: vitamin C, total phenols and flavonoids. The treatments tested were: 100% mineral fertilizer (control 1), 50% mineral fertilizer (control 2), 50% mineral fertilizer with microalgae, 50% mineral fertilizer with PGPR and 50% mineral fertilizer with AMF. The research was conducted during the winter months within a controlled environment of a glasshouse in a Mediterranean climate. The PGPR comprised three distinct bacterial strains, while the AMF comprised nine different mycorrhizal species. The microalgae consisted of only a single species, Chlorella vulgaris. AMF inoculation occurred once during seed sowing, while the introduction of PGPR and microalgae occurred at 10-day intervals into the root medium. Our findings revealed that the treatment with PGPR resulted in the highest growth parameters, including the lettuce circumference, stem diameter and fresh leaf weight. The 100% mineral fertilizer and PGPR treatments also yielded the highest lettuce production. Meanwhile, the treatment with AMF showed the highest total phenol and flavonoid content, which was statistically similar to that of the PGPR treatment. Furthermore, the PGPR recorded the maximum range of essential nutrients, including nitrogen (N), potassium (K), iron (Fe), zinc (Zn) and copper (Cu). Thus, the inclusion of PGPR holds promise for optimizing the lettuce growth and nutrient content in hydroponic systems. In conclusion, PGPR has the potential to enhance nutrient availability in a floating hydroponic system, reducing the dependence on chemical fertilizers. This mitigates environmental pollution and fosters sustainable agriculture.

Analysis of express sequence tags from Arbuscular Mycorrhizal fungi (AMF) express during the pre-symbiotic stage of the fungus

Arbuscular Mycorrhizal Fungi (AMF) are symbiotically associated with the roots of higher plants which enhance the overall nutritional status of plants. It is known that the overall growth and development of plants not only depend upon the performance of specific genotypes but their association is also affected by the various types of microbes. Therefore, the major aim of the study was the isolation and characterization of gene expression during the presymbiotic stage of AMF. In the present study, total RNA was extracted from spores of Rhizophagus irregularis grown under root organ culture (ROC). cDNA library was prepared and expressed sequence tag (EST) analysis was performed. Approximately 150 random clones were selected for EST sequencing analysis. Out of the 150 clones obtained, 1.5% carried inserts of the rRNA gene cluster. After excision, inserts from 72 randomly selected clones were sequenced. Database searches revealed that 74% of the clones had similarities to already known sequences. Putative genes for Ca2+-regulated symbiotic genes, cell cycle regulatory factors and precursors for lipid biosynthesis genes were discovered. A full-length mating gene was discovered using rapid amplification of cDNA ends (RACE). Studies revealed the presence of a putative mating type gene in mycorrhizal species that are evident in the sexual origin of AMF.