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Whilst transgenerational effects (TGE) of abiotic conditions are becoming generally accepted in plants, those of biotic interactions remain largely unexplored. We therefore investigated the influence of TGE due to arbuscular mycorrhiza, the most widespread mutualistic interaction of plants with microorganisms, on clonal and sexual offspring of Fragaria vesca. We hypothesized that the ecological and evolutionary significance of TGE will vary between clonal and sexual offspring based on mycorrhizal status and phosphorus (P) availability experienced by the parent. In a two‐generation greenhouse experiment, parental plants were exposed to full‐factorial combinations of mycorrhizal status and high or low P availability. TGE on mycorrhiza establishment and plant performance were evaluated in their clonal and sexual offspring, which experienced the parental or all non‐parental environments. Consistently in both generations, mycorrhiza improved plant growth at low P availability, but had no or even negative effect at high P availability, concomitantly with decreased root colonization by the arbuscular mycorrhizal (AM) fungus. TGE due to mycorrhiza was generally stronger in sexually derived offspring, both on mycorrhiza formation and plant growth. In sexual offspring, parental mycorrhizal status was adaptive if the offspring's mycorrhizal status was of disadvantage: for mycorrhizal offspring growing in high P availability and for non‐mycorrhizal offspring at low P availability. Synthesis: Our results suggest that clonal and sexual reproduction are under different evolutionary pressures, leading to the development of stronger TGE mechanisms in response to mycorrhizal symbiosis in the latter. The complexity of the observed effects highlights the need for disentangling the mechanisms contributing to the TGE in clonal and sexual reproduction. Our study underlines the importance of considering reproductive strategies and the interplay between environmental factors and TGE in understanding the ecological and evolutionary dynamics of plant–symbiotic interactions. [ABSTRACT FROM AUTHOR]

Summary: Mycorrhizal associations are key mutualisms that shape the structure of forest communities and multiple ecosystem functions. However, we lack a framework for predicting the varying dominance of distinct mycorrhizal associations in an integrated proxy of multifunctionality across ecosystems.Here, we used the datasets containing diversity of mycorrhizal associations and 18 ecosystem processes related to supporting, provisioning, and regulating services to examine how the dominance of ectomycorrhiza (EcM) associations affects ecosystem multifunctionality in subtropical mountain forests in Southwest China. Meanwhile, we synthesized the prevalence of EcM‐dominant effects on ecosystem functioning in forest biomes.Our results demonstrated that elevation significantly modified the distributions of EcM trees and fungal dominance, which in turn influenced multiple functions simultaneously. Multifunctionality increased with increasing proportion of EcM associations, supporting the ectomycorrhizal‐dominance hypothesis. Meanwhile, we observed that the impacts of EcM dominance on individual ecosystem functions exhibited different relationships among forest biomes.Our findings highlight the importance of ectomycorrhizal dominance in regulating multifunctionality in subtropical forests. However, this ectomycorrhizal feedback in shaping ecosystem functions cannot necessarily be generalized across forests. Therefore, we argue that the predictions for ecosystem multifunctionality in response to the shifts of mycorrhizal composition could vary across space and time. [ABSTRACT FROM AUTHOR]

Summary: Plants express diverse nutrient use and acquisition traits, but it is unclear how trait combinations at the species level are constrained by phylogeny, trait coordination, or trade‐offs in resource investment. One trait – nitrogen (N) fixation – is assumed to correlate with other traits and used to define plant functional groups, despite potential confounding effects of phylogeny.We quantified growth, carbon metabolism, fixation rate, root phosphatase activity (RPA), mycorrhizal colonization, and leaf and root morphology/chemistry across 22 species of fixing and nonfixing tropical Fabaceae trees under common conditions.Belowground trait variation was high even among closely related species, and most traits displayed a phylogenetic signal, including N‐fixation rate and nodule biomass. Across species, we observed strong positive correlations between physiological traits such as RPA and root respiration. RPA increased ~ fourfold per unit increase in fixation, supporting the debated hypothesis that N‐fixers 'trade' N for phosphatases to enhance phosphorus acquisition. Specific root length and root N differed between functional groups, though for other traits, apparent differences became nonsignificant after accounting for phylogenetic nonindependence.We conclude that evolutionary history, trait coordination, and fixation ability contribute to nutrient trait expression at the species level, and recommend explicitly considering phylogeny in analyses of functional groupings. [ABSTRACT FROM AUTHOR]

The survival and productivity of potato plantlets transplanted from in vitro to commercial hydroponic minituber culture are crucial. Mycorrhizal fungi are an efficient tool to enhance potato nutrient uptake, survival, and productivity under these conditions. This study aimed to assess the effect of mycorrhizal fungi on improving the yield of minitubers and nutrient uptake in potatoes transferred from the in vitro environment to the greenhouse. This study was conducted in a greenhouse in Hamadan province, I.R. Iran, in 2013. The experimental design was factorial, including treatments with and without inoculation with the mycorrhizal fungus Rhizophagus irregularis and varying phosphorus (P) concentrations in Hoagland's solution (100%, 75%, 50%, and 25% of its maximum content, i.e. 0.965, 0.482, 0.241, and 0.12 mM H2PO4-) with three replications on potato plantlets transferred from in vitro to pots. The results indicated that the highest colonization percentage was achieved with 25% P and inoculation. The highest number of minitubers (8.9), total minituber weight per plant (53.2 grams), plant height (54.6 cm), minituber (0.38%) and leaf (0.363%) P content, minituber (33 mg/kg) and leaf (65 mg/kg) manganese (Mn) content, and minituber (38 mg/kg) and leaf (65 mg/kg) zinc (Zn) content were obtained with inoculation and 75% P of Hoagland nutrient solution, which was statistically comparable to the inoculation with 100% P treatment. In summary, inoculating potato plantlets with mycorrhiza can enhance minituber yield and nutrient uptake and potentially replace approximately 50% of the P requirement in hydroponic solutions. [ABSTRACT FROM AUTHOR]

The frequency of consecutive drought years is predicted to increase due to climate change. These droughts have strong negative impacts on forest ecosystems. Mixing tree species is proposed to increase the drought resistance and resilience of tree communities. However, this promising diversity effect has not yet been investigated under extreme drought conditions and in the context of complementary mycorrhizal associations and their potential role in improving water uptake.Here, we investigate whether tree diversity promotes growth resistance and resilience to extreme drought and whether drought responses are modulated by mycorrhizal associations. We used inventory data (2015–2021) from a young tree diversity experiment in Germany, manipulating tree species richness (1, 2 and 4 species) and mycorrhizal type (communities containing arbuscular mycorrhizal [AM] or ectomycorrhizal [EM] tree species, or both). For all tree communities, we calculated basal area increment in the periods before, during and after drought and used the concepts of resistance and resilience to quantify growth responses to drought.We found strong growth declines during the extreme 2018–2020 drought for most tree communities. Contrary to our hypothesis, we did not find that tree species richness per se can buffer the negative impacts of extreme drought on tree growth. However, while for EM communities, drought resistance and resilience decreased with tree species richness, they increased for AM communities and communities comprising both mycorrhizal types. We highlight that among various mixtures of tree species, only those with mixed mycorrhizal types outperformed their respective monocultures during and after drought. Furthermore, under extreme drought, the community tends to segregate into 'winner' and 'loser' tree species in terms of diversity, indicating a possible intensification of competition.While we cannot disentangle the underlying mechanisms or clarify the role of mycorrhiza during drought, our findings suggest that mixtures of mycorrhizal types within tree communities could help safeguard forests against increasing drought frequency.Synthesis. Drought resistance and resilience of tree communities depend on tree diversity and mycorrhizal association types. Mixing tree species with diverse mycorrhizal types holds promise for forest restoration in the face of climate change. [ABSTRACT FROM AUTHOR]

This article explores the role of LysM receptors, specifically LYS6 and LYS7, in regulating arbuscular mycorrhiza (AM) in Lotus japonicus. AM is a beneficial interaction between plants and fungi that aids in nutrient exchange. The study found that LYS7 is upregulated in roots infected with AM fungi, suggesting its involvement in AM. Mutants lacking LYS6 and LYS7 showed reduced colonization and arbuscule formation by AM fungi, highlighting the importance of these receptors in AM regulation. The study also revealed that LYS6 is involved in the expression of AM-induced genes and the induction of calcium spiking. Overall, LYS6 and LYS7, along with their downstream signaling pathways, are crucial for the initial response to AM in Lotus japonicus. [Extracted from the article]

The textile industry generates waste with elevated concentrations of heavy metals, dominated by lead (Pb). This waste can contaminate the surrounding agricultural land and be absorbed by plants, accumulating in their tissues. Applying mycorrhiza fungi is an effective strategy to prevent Pb accumulation and translocation in plant tissues. This study evaluates the effect of combining mycorrhiza with vermicompost in chili plants by analyzing Pb uptake, Pb translocation, phosphorus uptake, and harvest yield. We employed a randomized block design with two factors: the first factor was vermicompost dose (ranging from 0, 10, 15, 20, 30 t ha-1), and the second factor was mycorrhiza application and non-mycorrhizal (with three repetitions per treatment). The results showed that vermicompost at a dose of 25 - 30 t ha-1 combined with mycorrhiza increased the Pb content in the root compared with the control treatment. Vermicompost at 0 and 10 t ha-1 doses combined with mycorrhiza decreased significantly in Pb content in the shoot compared to the vermicompost treatment without mycorrhiza. Mycorrhiza did not increase the P-uptake and the yield of chili plants. Meanwhile, vermicompost at 25 -30 t ha-1 increased significantly the plant chili yield. The mycorrhizal hyphae in the root tissue can bind Pb and suppress further Pb translocation to the plant's shoot. These research findings show that the chili plant is known as a Pb-accumulator plant. This research contributes to understanding the role of mycorrhiza and vermicompost in maintaining the safety of food crops cultivated around river areas contaminated with textile waste containing Pb. [ABSTRACT FROM AUTHOR]

The utilization of saline water for irrigating plants in arid and semi-arid regions has become imperative because of the scarcity of water resources. Nevertheless, under salt stress conditions, plants undergo a multitude of variation, which result in delayed growth and adversely affect the plant metabolism. Adopting appropriate and sustainable strategies such as using bio-organic fertilizers from animal and plant waste or integrating microorganisms (symbiotic fungi), can improve plant resilience against salt stress. The purpose of this study was to elucidate the impact of arbuscular mycorrhizal fungus (AMF) Rhizophagus irregularis alone and/or combined with compost on growth, nutrient uptake, antioxidant activities, and photosynthesis-related performance of Stevia rebaudiana Bertoni under salt stress conditions. Salt stress negatively affected all studied parameters. However, the application of R. irregulare strain in a substrate amended with 5% compost is more effective in enhancing salt stress tolerance in stevia plants compared to the compost and AMF strain applied separately. The synergistic effect of the co-application of these two biofertilizers under salt stress resulted in increased stomatal conductance (276%), chlorophyll fluorescence (38%), antioxidant enzyme activities, and the uptake of K+ (78%), Ca2+ (117%), and P (149%). In conclusion, the application of compost combined with AMF may be a promising sustainable strategy for improving salt stress resistance in stevia. [ABSTRACT FROM AUTHOR]

This article explores the recruitment of arbuscular mycorrhizal (AM) conserved genes for ectomycorrhizal (ECM) symbiosis. ECM symbiosis, which is a more recent form of symbiosis than AM symbiosis, involves the formation of a mantle around the root and an intercellular Hartig net. The study found that ECM host species from the Fagales order maintained the majority of AM-conserved genes, unlike other non-AM hosts. Transcriptome analysis revealed that several of these maintained genes were induced in ECM symbiosis, suggesting that ECM formation recruits AM-derived mechanisms. The study focuses on ECM-only hosts, which are plant species that exclusively engage in ECM symbiosis and have lost the ability to form AM symbiosis. The researchers discovered that ECM-only hosts maintain 64% of the AM-conserved orthologous groups (OGs), highlighting the importance of these genes in ECM symbiosis. They also identified specific genes, such as RAM2, involved in lipid biosynthesis and arbuscule formation in ECM roots. The study suggests that the preservation of AM-conserved genes in ECM-only hosts supports their role in ECM symbiosis. [Extracted from the article]

Mucoromycotina fine root endophytes have similar ecological functions as arbuscular mycorrhizal fungi in assisting plant nutrient uptake. The mechanisms enabling their symbiosis with plants remain largely unexplored. The mechanisms of Mucoromycotina fine root endophyte symbioses may overlap with those regulating arbuscular mycorrhizal fungal symbioses or the plant endophytes Colletotrichum tofieldiae and Serendipita indica. Contrasting colonisation mechanisms between Mucoromycotina fine root endophytes and arbuscular mycorrhiza fungi could provide insights into how ancient fungi facilitated the terrestrialisation of land plants. Investigations into mechanisms of symbiosis will benefit from inclusion of Mucoromycotina fine root endophytes as these fungi are more culturable than arbuscular mycorrhizal fungi under laboratory conditions and can be grown in the absence of a plant host. The most studied plant–fungal symbioses to date are the interactions between plants and arbuscular mycorrhizal (AM) fungi of the Glomeromycotina clade. Advancements in phylogenetics and microbial community profiling have distinguished a group of symbiosis-forming fungi that resemble AM fungi as belonging instead to the Mucoromycotina. These enigmatic fungi are now known as Mucoromycotina 'fine root endophytes' and could provide a means to understand the origins of plant–fungal symbioses. Most of our knowledge of the mechanisms of fungal symbiosis comes from investigations using AM fungi. Here, we argue that inclusion of Mucoromycotina fine root endophytes in future studies will expand our understanding of the mechanisms, evolution, and ecology of plant–fungal symbioses. [ABSTRACT FROM AUTHOR]

The use of mycorrhiza and seaweed are becoming significant and complementary applications in different production systems because organisms increased quality of seedlings and crop yield. This study has been conducted under growth chamber conditions to determine some of the seedling growth parameters (length (cm), stem diameter (mm), fresh weight (g plant −1), dry weight (g plant −1), root fresh weight (g plant −1), root dry weight (g plant −1), leaf area (cm2 plant−1), SPAD, photosynthesis rate (%) and color parameters). As a plant material, Cuma F1 and Mert F1 genotype seeds were sown. Endo Roots Soluble (Mycorrhiza (ERS)) and MC-Extra (Seaweed) were applied in different doses (0, 250 and 500 mg kg−1) to seedling growing vessels at a rate of 10 ml per plant. Treatment effects in tomato were found statistically significant (p ≤.01**) on stem diameter, fresh weight, dry weight. Seedling length, leaf area and SPAD results were also statistically significant (p ≤.01**), and the results of these parameters were higher in ERS. ERS increases the leaf area and SPAD measurements in tomato seedlings. The results of pepper measurements were found to be statistically significant at p ≤.05* on root fresh weight, SPAD and photosynthesis rate. The highest values of root fresh weight, SPAD were obtained from 250 mg kg−1 doses of ERS; the highest value of photosynthesis rate was measured from 500 mg kg−1 doses of ERS on pepper. The effect of 500 mg kg−1 ERS on seedling growth was found statistically significant in pepper. [ABSTRACT FROM AUTHOR]

This article is a Commentary on Giovannetti et al., 241: 1393–1400. [ABSTRACT FROM AUTHOR]

Summary: Arbuscular mycorrhizal fungi (AMF) transport substantial plant carbon (C) that serves as a substrate for soil organisms, a precursor of soil organic matter (SOM), and a driver of soil microbial dynamics. Using two‐chamber microcosms where an air gap isolated AMF from roots, we 13CO2‐labeled Avena barbata for 6 wk and measured the C Rhizophagus intraradices transferred to SOM and hyphosphere microorganisms.NanoSIMS imaging revealed hyphae and roots had similar 13C enrichment. SOM density fractionation, 13C NMR, and IRMS showed AMF transferred 0.77 mg C g−1 of soil (increasing total C by 2% relative to non‐mycorrhizal controls); 33% was found in occluded or mineral‐associated pools.In the AMF hyphosphere, there was no overall change in community diversity but 36 bacterial ASVs significantly changed in relative abundance. With stable isotope probing (SIP)‐enabled shotgun sequencing, we found taxa from the Solibacterales, Sphingobacteriales, Myxococcales, and Nitrososphaerales (ammonium oxidizing archaea) were highly enriched in AMF‐imported 13C (> 20 atom%). Mapping sequences from 13C‐SIP metagenomes to total ASVs showed at least 92 bacteria and archaea were significantly 13C‐enriched.Our results illustrate the quantitative and ecological impact of hyphal C transport on the formation of potentially protective SOM pools and microbial roles in the AMF hyphosphere soil food web. [ABSTRACT FROM AUTHOR]

Summary: Phosphorus (P) for carbon (C) exchange is the pivotal function of arbuscular mycorrhiza (AM), but how this exchange varies with soil P availability and among co‐occurring plants in complex communities is still largely unknown.We collected intact plant communities in two regions differing c. 10‐fold in labile inorganic P. After a 2‐month glasshouse incubation, we measured 32P transfer from AM fungi (AMF) to shoots and 13C transfer from shoots to AMF using an AMF‐specific fatty acid. AMF communities were assessed using molecular methods.AMF delivered a larger proportion of total shoot P in communities from high‐P soils despite similar 13C allocation to AMF in roots and soil. Within communities, 13C concentration in AMF was consistently higher in grass than in blanketflower (Gaillardia aristata Pursh) roots, that is P appeared more costly for grasses. This coincided with differences in AMF taxa composition and a trend of more vesicles (storage structures) but fewer arbuscules (exchange structures) in grass roots. Additionally, 32P‐for‐13C exchange ratios increased with soil P for blanketflower but not grasses.Contrary to predictions, AMF transferred proportionally more P to plants in communities from high‐P soils. However, the 32P‐for‐13C exchange differed among co‐occurring plants, suggesting differential regulation of the AM symbiosis. [ABSTRACT FROM AUTHOR]

Summary: Arbuscular (AM) and orchid (OrM) mycorrhiza are the most widespread mycorrhizal symbioses among flowering plants, formed by distinct fungal and plant species. They are both endosymbioses because the fungal hyphae can enter inside the plant cell to develop intracellular fungal structures that are surrounded by the plant membrane. The symbiotic plant–fungus interface is considered to be the major site of nutrient transfer to the host plant. We summarize recent data on nutrient transfer in OrM and compare the development and function of the arbuscules formed in AM and the pelotons formed in OrM in order to outline differences and conserved traits. We further describe the unexpected similarities in the form and function of the intracellular mycorrhizal fungal structures observed in orchids and in the roots of mycoheterotrophic plants forming AM. We speculate that these similarities may be the result of convergent evolution of mycorrhizal types in mycoheterotrophic plants and highlight knowledge gaps and new research directions to explore this scenario. [ABSTRACT FROM AUTHOR]

Summary: Rhizophagus irregularis is the model species for arbuscular mycorrhizal fungi (AMF) research and the most widely propagated species for commercial plant biostimulants.Using asymbiotic and symbiotic cultivation systems initiated from single spores, advanced microscopy, Sanger sequencing of the glomalin gene, and PacBio sequencing of the partial 45S rRNA gene, we show that four strains of R. irregularis produce spores of two distinct morphotypes, one corresponding to the morphotype described in the R. irregularis protologue and the other having the phenotype of R. fasciculatus.The two spore morphs are easily distinguished by spore colour, thickness of the subtending hypha, thickness of the second wall layer, lamination of the innermost layer, and the dextrinoid reaction of the two outer spore wall layers to Melzer's reagent. The glomalin gene of the two spore morphs is identical and that of the PacBio sequences of the partial SSU‐ITS‐LSU region (2780 bp) obtained from single spores of the R. cf fasciculatus morphotype has a median pairwise similarity of 99.8% (SD = 0.005%) to the rDNA ribotypes of R. irregularis DAOM 197198.Based on these results, we conclude that the model AMF species R. irregularis is dimorphic, which has caused taxonomic confusion in culture collections and possibly in AMF research. [ABSTRACT FROM AUTHOR]

The hydrological regime is considered to be the major factor that affects the distribution of arbuscular mycorrhiza (AM) fungi in wetlands. We aimed to investigate the responses of AM fungal community to different hydrological gradients. Illumina Miseq sequencing technology was used to study the AM fungal community structure in roots and rhizosphere soils of Phragmites australis in different moisture areas (dry area, alternating wet and dry area, and flooded area) in Mengjin Yellow River wetland. The rhizosphere soils and roots hosted different AM fungal communities. In roots, the AM fungal colonization and Chao1 richness in dry area were significantly higher than that in alternating wet and dry area and flooded area, but the community composition did not vary clearly under different water conditions. In rhizosphere soils, the Chao1 richness of AM fungi in flooded area was significantly higher than that in alternating wet and dry area and dry area, and the AM fungal community structure obviously differed across different areas. The redundancy analyses indicated that changes in the AM fungal community in soils were associated with altered soil properties, and the abundance of the dominant genus Glomus was mostly positively correlated with alkali‐hydrolyzable nitrogen in soils. This study helps us to understand the responses of AM fungal community to hydrological gradients in wetlands. [ABSTRACT FROM AUTHOR]

The hydrological regime is considered to be the major factor that affects the distribution of arbuscular mycorrhiza (AM) fungi in wetlands. We aimed to investigate the responses of AM fungal community to different hydrological gradients. Illumina Miseq sequencing technology was used to study the AM fungal community structure in roots and rhizosphere soils of Phragmites australis in different moisture areas (dry area, alternating wet and dry area, and flooded area) in Mengjin Yellow River wetland. The rhizosphere soils and roots hosted different AM fungal communities. In roots, the AM fungal colonization and Chao1 richness in dry area were significantly higher than that in alternating wet and dry area and flooded area, but the community composition did not vary clearly under different water conditions. In rhizosphere soils, the Chao1 richness of AM fungi in flooded area was significantly higher than that in alternating wet and dry area and dry area, and the AM fungal community structure obviously differed across different areas. The redundancy analyses indicated that changes in the AM fungal community in soils were associated with altered soil properties, and the abundance of the dominant genus Glomus was mostly positively correlated with alkali‐hydrolyzable nitrogen in soils. This study helps us to understand the responses of AM fungal community to hydrological gradients in wetlands. [ABSTRACT FROM AUTHOR]

Vanda tricolor is currently a protected species because is the occurrence of orchid late blight caused by the Fusarium sp. pathogenic fungus. The objective of this study was to investigate the effectiveness of Rhizoctonia mycorrhizae in inducing resistance against Fusarium sp., the causative agent of late blight, in V. tricolor. The research employed CRBD with three treatments and six replications. Rhizoctonia mycorrhizae were isolated and identified following the procedure outlined by Bayman. Pre-inoculation of Rhizoctonia mycorrhizae was conducted on PDA media, and mycorrhizae were subsequently inoculated onto the roots of V. tricolor seedlings derived from tissue culture. The presence of peloton structures on the roots was determined using the Nakano methods. The Saravanan method was employed to measure peroxidase activity. The results demonstrated that V. tricolor induced by Rhizoctonia mycorrhizae exhibited resistance against Fusarium sp. and displayed the formation of peroxidase enzymes, peloton structures, and lignification. In contrast, the non-induced orchids suffered significant damage to the epidermal tissue of the leaves, did not exhibit an increase in peroxidase enzymes, and failed to form peloton or lignified structures. The novelty of this research is the use of Rhizoctonia mycorrhizae to control orchid late blight diseases at Mount Merapi. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal (AM) fungi frequently colonise plant roots and can affect plant morphology and physiology through their contribution to plant nutrition. However, the functional role of AM fungi in the presence of other microbial symbionts, including widespread Mucoromycotina 'fine root endophytes' (MFRE) fungi, remains largely unknown.While both AM fungi and MFRE transfer nutrients, including nitrogen, from inorganic and organic sources to host plants, their combined effects on co‐colonised plants have only been investigated in liverworts. Here, we compare the morphology and physiology of the grass Holcus lanatus grown with an AM fungal community versus a more diverse symbiotic fungal community containing both AM fungi and MFRE.Holcus lanatus plants were grown in the presence of either a diverse MFRE+AM fungi soil inoculum or a multi‐species AM fungal inoculum. Plant traits associated with growth were quantified, along with fungal transfer of 15N tracer to plants from a variety of sources (ammonium chloride, alanine, glycine and algal necromass).Holcus lanatus grown with the AM fungal community had greater root and shoot growth during early development and prior to the addition of 15N‐labelled sources, compared with plants grown with the more diverse symbiotic fungal community. When nitrogen sources were made available to the fungal symbionts in the pot microcosms, plants growing with the MFRE+AM fungi soil inoculum had a faster growth rate than plants growing with the AM fungal community. At harvest, H. lanatus grown with the AM fungal community had a larger biomass, and there were no differences in 15N tracer assimilation in plants across the two fungal community treatments.Our results demonstrate that the diversity of fungal inocula in conjunction with soil nutrient availability determine the benefits derived by plants from diverse fungal symbionts. Our research contributes to understanding host plant outcomes in diverse multi‐symbiont scenarios. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Interview with Caroline Gutjahr, who studies the molecular factors influencing the formation and function of mycorrhiza at the Max Planck Institute of Molecular Plant Physiology, where she is also the Director. [ABSTRACT FROM AUTHOR]

This article is a Commentary on Yamawo & Ohno (2024), 243: 1586–1599. [ABSTRACT FROM AUTHOR]

To evaluate the effect of using mycorrhizae and rhizobium at different levels of nitrogen starter fertilizer on some important growth indices of a common bean cultivar, a factorial experiment was conducted in a randomized complete block design with three replications in 2016 at Bu-Ali Sina University research farm. The factors included two bio-fertilizers of mycorrhizae (Glomus mosseae) and rhizobium (Rhizobium phaseoli) each one with two levels (used and non-used) and nitrogen starter fertilizer with three levels (0, 30, 60 kg ha−1) from urea as the third factor. The studied factors caused significant changes in growth indices. The maximums of leaf area index (5.9), total dry weight (860 g m−2) and crop growth rate (44 g m−2 day−1) were observed in the simultaneous application of both bio-fertilizers plus use of 60 kg ha−1 N. This superior treatment compared with no bio-fertilizer + 60 kg ha−1 N treatment increased maximums of LAI, TDM and CGR, 115, 68 and 60%, respectively. Also in superior treatment, the two indices of net assimilation rate (NAR) and relative growth rate (RGR) on 60th day after planting were 25 g m−2 day−1 and 0.046 g g−1day−1, that were respectively 116 and 17% higher than no bio-fertilizer + 60 kg ha−1 N treatment. Therefore application of mycorrhiza and rhizobium simultaneously in addition to 60 kg ha−1 N as starter fertilizer is an appropriate treatment in common bean to maximize the growth indices. [ABSTRACT FROM AUTHOR]

To investigate the effect of soil additives in reducing the effect of water deficit stress on sugar beet, an experiment was performed as a combined analysis in two regions based on randomized complete block design with four replications. Experimental treatments were location factor at two levels of Miandoab and Malekan, water deficit stress factor at three levels of 50 mm (lack of stress), 110 mm (moderate stress) and 170 mm (severe stress) evaporation from class A evaporation pan and soil additive factor at four levels of control (no soil additives), superabsorbent, mycorrhiza and livestock manure. In the present study, the use of soil additive treatments in both regions were able to improve the yield of pure sugar compared to control. In irrigation treatment after 170 mm of evaporation, the highest leaf area index (3.28), relative leaf water content (65.96%), shoot dry weight (3.45 t ha-1 ), root yield (49.48 t ha-1 ), gross sugar yield (9.73 t ha-1 ) and pure sugar yield (8.32 t ha-1 ) were obtained by mycorrhiza application and sugar content (20.48%) and pure sugar percent (17.11%) were obtained in control and superabsorbent application, respectively. In water deficit stress, application of mycorrhiza and superabsorbent were able to significantly increase the yield of pure sugar compared to the control. Due to the fact that sugar beet is exposed to different periods of water deficit stress in the tested areas, the use of mycorrhiza and superabsorbent can be a suitable method to reduce the effect of water deficit stress in sugar beet. [ABSTRACT FROM AUTHOR]

Meeting the ever-increasing food demands of a growing global population while ensuring resource and environmental sustainability presents significant challenges for agriculture worldwide. Arbuscular mycorrhizal symbiosis (AMS) has emerged as a potential solution by increasing the surface area of a plant's root system and enhancing the absorption of phosphorus, nitrogen nutrients, and water. Consequently, there is a longstanding hypothesis that rice varieties exhibiting more efficient AMS could yield higher outputs at reduced input costs, paving the way for the development of Green Super Rice (GSR). Our prior research study identified a variant, OsCERK1DY, derived from Dongxiang wild-type rice, which notably enhanced AMS efficiency in the rice cultivar "ZZ35." This variant represents a promising gene for enhancing yield and nutrient use efficiency in rice breeding. In this study, we conducted a comparative analysis of biomass, crop growth characteristics, yield attributes, and nutrient absorption at varying soil nitrogen levels in the rice cultivar "ZZ35" and its chromosome single-segment substitution line, "GJDN1." In the field, GJDN1 exhibited a higher AM colonization level in its roots compared with ZZ35. Notably, GJDN1 displayed significantly higher effective panicle numbers and seed-setting rates than ZZ35. Moreover, the yield of GJDN1 with 75% nitrogen was 14.27% greater than the maximum yield achieved using ZZ35. At equivalent nitrogen levels, GJDN1 consistently outperformed ZZ35 in chlorophyll (Chl) content, dry matter accumulation, major nutrient element accumulation, N agronomic efficiency (NAE), N recovery efficiency (NRE), and N partial factor productivity (NPFP). The performance of OsCERK1DY overexpression lines corroborated these findings. These results support a model wherein the heightened level of AMS mediated by OsCERK1DY contributes to increased nitrogen, phosphorus, and potassium accumulation. This enhancement in nutrient utilization promotes higher fertilizer efficiency, dry matter accumulation, and ultimately, rice yield. Consequently, the OsCERK1DY gene emerges as a robust candidate for improving yield, reducing fertilizer usage, and facilitating a transition towards greener, lower-carbon agriculture. [ABSTRACT FROM AUTHOR]

In this study, the effect of mycorrhiza (Glomus intraradices N.C. Schenck & G.S. Sm.) inoculation on the micronutrient and macroelement uptakes in different organs of daffodil (Narcissus tazetta L.) grown under saline conditions is examined. For this purpose, Narcissus tazetta plant grown in the climate chamber was treated with sodium chloride (NaCl) at three different concentrations such as salt-free (S0), 34 mmol (S1) and 68 mmol (S2) in mediums with mycorrhiza (M+) and without mycorrhiza (M-). At the end of the experiment, the uptakes of sodium (Na), iron (Fe), manganese (Mn), zinc (Zn) and copper (Cu) uptakes in the bulb, root and leaves of the plant were analyzed. The effects of salt and mycorrhiza interactions on the N uptakes were statistically significant at the 5% level in bulbs. The effects of salt applications were found significant at 1% level for all nutrients uptakes of roots except Cu uptake (5%). The effects of interactions among salt and mycorrhiza were found significant at 5% level for P, Ca and Mn uptakes and at 1% level for Mg, Fe and Cu uptakes of leaves statistically. Increasing doses of sodium chloride had statistically negative effects on nutrient uptakes of different organs except Na and K uptakes of bulbs. Mycorrhiza applications generally increased nutrient uptakes of daffodil's roots and leaves under salinity conditions. The interactions between salt and mycorrhiza were significant for N in bulbs, for N, P and Fe in roots and for P, Ca, Mg, Fe, Mn and Cu in leaves. The decreases in these nutrients uptakes by 68 mmol NaCl applications were lower in mycorrhiza applications than those in non mycorrhiza applications. [ABSTRACT FROM AUTHOR]

The maintenance of growth and crop productivity under water deficit represents one of the main challenges of modern agriculture. In this research, the role of foliar spraying with putrescine (0, 0.5, and 1 mM), soil application of humic acid, and soil application of arbuscular mycorrhizal fungi) in reducing the negative effect of irrigation regime[full irrigation or control, stopping irrigation from the beginning of flowering (moderate drought) and the beginning of branching (severe drought) respectively] on the morphological and biochemical indicators of Balangu (Lallemantiaroyleana Benth. in Wall.) plants was investigated. The experiment was set up in three replications, utilizing a split-plot design based on a randomized complete block design. Moderate and severe drought levels decreased morphological parameters and leaf elements, while increasing proline, soluble carbohydrate content, reactive oxygen species, and total phenol. The use of putrescine, humic acid, and Arbuscular mycorrhizal fungi reduced the adverse effects of drought stress on plant height, fresh and dry weight, crown diameter, lateral bench number, leaf length, and width. They also increase proline and soluble carbohydrate content, which increases the plant's resistance to stress conditions. Humic acid and Arbuscular mycorrhizal fungi increased the content of soluble carbohydrates by 30 and 22% and proline by 72 and 72% under severe drought stress conditions, while decreasing reactive oxygen species by 25 and 19%. In general, with the stopping of irrigation from the beginning of flowering, the growth characteristics of the plant decreased, but with the use of growth stimulants, the negative effects of the drought stress were moderated. [ABSTRACT FROM AUTHOR]

Background: Water is one of the factors limiting rice cultivation on raindrop land. The provision of mycorrhizae can help the absorption of water in the soil solum deeper. Besides, it can also save the use of nitrogen and phosphor fertilizers in water-choked conditions. This research aimed to optimize dosage of nitrogen and phosphorus fertilizers on growth in rainfed lowland rice applied mycorrhizae. Methods: This research was carried out from April to July 2019 in rainfed lowland rice with entisol in Demangan, Sambi, Boyolali, Center Java, Indonesia The research method was a randomized complete block design (RCBD) with three replications. The first factor was the dosage of nitrogen fertilizer, which consisted of four levels, i.e., 0, 45, 90 and 135 kg ha-1. The second factor was the dosage of phosphorus fertilizer, which consisted of four levels, i.e., 0, 25, 50 and 75 kg ha-1. Result: The results showed that fertilizer dosage of nitrogen of 90 kg ha-1 and phosphorus of 50 kg ha-1 increased the leaf area index (LAI), leaf area duration (LAD), net assimilation rate (NAR), and crop growth rate (CGR). The application of nitrogen and phosphorus fertilizer can improve the Situ Bagendit variety's physiological character better than without fertilizer. Rice cultivation in rainfed lowland rice applied mycorrhizae should use nitrogen of 90 kg ha-1 and phosphorus of 50 kg ha-1. [ABSTRACT FROM AUTHOR]

This study aimed to determine the effectiveness of the use of host plants in an effort to multiply mycorrhizal propagules indigenous to Gunung Ciremai National Park. The experimental method used a factorial complete randomized design with 2 factors. The first factor was the location of the source of inoculum by 3 levels: mixed forests, shrubs, and pine stands. The second factor was 4 types of host plant many as 4 levels: corn (Zea mays), sorghum (Sorghum bicolor. (L.) Moench), centro beans (Centrosema pubescens), and ruji beans (Pueraria javanica). Each treatment was repeated five times, so there were 60 experimental units. The spores were isolated by wet filtration and decantation methods adapted from Gerdemann and Nicolson (1963), followed by the modified sugar centrifugation method from Jenkins (1964). The observed parameter was the number of mycorrhizal spores. The data obtained were analyzed by a variance test (F test). To evaluate the treatment's effect and compare the selected treatments, Duncan's follow-up test was used at the level of 5%. The combination of the location of the shrub inoculum and the centro bean host plant showed the largest spore population, which was 222.60 per 50 g soil sample. Trapping techniques using host plants of corn, sorghum, centro beans, and ruji beans showed suboptimal results. The most common genera were Glomus (80%; 4 species), Gigaspora (10%, 1 species), and Acaulospora (10%, 1 species). Glomus was evenly found in all trapping results. [ABSTRACT FROM AUTHOR]

The coming century in agriculture will be marked by increasing exposure of crops to abiotic stress and disease due to climate change. The plant traits with the strongest potential to mitigate these stresses are complex, and are increasingly recognized to involve interaction with the microbiome. Through symbiosis with soil fungi, plants form arbuscular mycorrhizae (AM) that can alleviate nutrient, water, and temperature stress, and can confer pathogen resistance and increased yield. The portfolio of advantages offered by AM overlaps with the benefits of agriculturally useful plant traits that have been the subject of decades of intensive biotechnological efforts, such as C4 photosynthesis and rhizobial nitrogen fixation. In this article we illustrate the prospective benefits of genetic engineering to produce AM in nonmycorrhizal plants and modify AM in already-mycorrhizal crops. We highlight recent advances which have clarified the key genetic and metabolic components of AM symbiosis, and show that many of these components are involved in other plant biological processes and have already been subject to extensive genetic engineering in nonsymbiotic contexts. We provide a theoretical research roadmap to accomplish engineering of AM into the nonmycorrhizal model Arabidopsis including specific molecular genetic approaches. We conclude that AM is potentially more tractable than other complex plant traits, and that a concerted research initiative for biotechnological manipulation of AM could fill unique needs for agricultural resilience. Finally, we note that engineering of AM provides a potential back door into manipulation of other essential plant traits, including carbon storage, and beneficial microbiome assembly. [ABSTRACT FROM AUTHOR]

Orchids are a diverse and widespread family of flowering plants, with over 25,000 known species and more than 100,000 hybrids and cultivars. Orchids are characterised by their often showy and highly specialised flowers and have unique and intricate floral. Orchids are known to be highly dependent on their mycorrhizal fungi for nutrient uptake, especially during the early stages of their development. Orchid seeds lack the endosperm present in most other seeds, which means they cannot germinate without a source of nutrition. The relationship between orchids and mycorrhiza is known as orchid mycorrhizae or orchid mycorrhiza. In orchid mycorrhiza, the orchid plant forms a mutualistic relationship with certain species of fungi that are able to penetrate the orchid's roots and colonise its tissues to provides the orchid with essential nutrients. Orchid mycorrhizal fungi are often highly specific, meaning that they can only form partnerships with certain orchid species, and vice versa. The importance of mycorrhizal fungi in the orchid life cycle is crucial from both evolutionary and ecological standpoints. Therefore, it is essential to acquire a thorough comprehension of this relationship and develop methodologies for isolating, identifying, and preserving significant fungal strains that are associated with different orchid species. In recent years, there has been a considerable increase in research concentration on mycorrhizal interactions in orchids. However, certain inquiries remain unresolved pertaining to the fungal communities associated with orchids as well as the divergences notices across different species and geographical locales. The present paper provides a through, and extensive analysis of the fungal life associated with orchids. This article presents a succinct overview of the molecular techniques utilised by researchers globally to isolate and identify pelotonforming fungi in both temperateterrestrial and tropical orchids. The review begins by proving a concise introduction to the background material regarding the wide range of fungal species that are linked with orchids. It then proceeds to explores the topic of orchid mycorrhizal fungi (OMF) and orchid nonmycorrhizal fungi (ONF). The subsequent analysis explores the crucial function that orchid mycorrhizal fungi play in the processes of seed germination and development. Moreover, the study elaborates on the methodologies utilised for isolating fungi, extracting fungal DNA, selecting primers, amplifying DNA and subsequent analysis sequence data. This article considers several molecular identification approaches that are used in studying orchid endophytic mycorrhizal. Using molecular approaches, orchid mycorrhizal can be further explored and identified. [ABSTRACT FROM AUTHOR]

SUMMARY: Tree growth and survival are dependent on their ability to perceive signals, integrate them, and trigger timely and fitted molecular and growth responses. While ectomycorrhizal symbiosis is a predominant tree‐microbe interaction in forest ecosystems, little is known about how and to what extent it helps trees cope with environmental changes. We hypothesized that the presence of Laccaria bicolor influences abiotic cue perception by Populus trichocarpa and the ensuing signaling cascade. We submitted ectomycorrhizal or non‐ectomycorrhizal P. trichocarpa cuttings to short‐term cessation of watering or ozone fumigation to focus on signaling networks before the onset of any physiological damage. Poplar gene expression, metabolite levels, and hormone levels were measured in several organs (roots, leaves, mycorrhizas) and integrated into networks. We discriminated the signal responses modified or maintained by ectomycorrhization. Ectomycorrhizas buffered hormonal changes in response to short‐term environmental variations systemically prepared the root system for further fungal colonization and alleviated part of the root abscisic acid (ABA) signaling. The presence of ectomycorrhizas in the roots also modified the leaf multi‐omics landscape and ozone responses, most likely through rewiring of the molecular drivers of photosynthesis and the calcium signaling pathway. In conclusion, P. trichocarpa‐L. bicolor symbiosis results in a systemic remodeling of the host's signaling networks in response to abiotic changes. In addition, ectomycorrhizal, hormonal, metabolic, and transcriptomic blueprints are maintained in response to abiotic cues, suggesting that ectomycorrhizas are less responsive than non‐mycorrhizal roots to abiotic challenges. Significance Statement: Current research on tree physiology primarily focuses on tree responses to abiotic stress, with little emphasis on root‐associated mutualistic fungi. Our results provide insights into how and to what extent the presence of ectomycorrhizas modifies host responses to abiotic changes: symbiosis has local and systemic impacts on host signaling pathways. A better understanding of the molecular mechanisms underpinning root‐microbe mutualistic interactions under abiotic stress will allow for robust modeling of tree adaptation to environmental challenges. [ABSTRACT FROM AUTHOR]

In sustainable agricultural ecosystem management, a key focus is on minimizing chemical fertilizer use and maximizing the use of non-chemical alternatives. Our study was designed to explore the impact of mycorrhizal fungi and humic acid (HA) on the quantitative and qualitative characteristics of faba beans under varying chemical fertilizer levels. The experiment involved different treatments, which included HA and mycorrhiza in four variations (control, HA, HA+ mycorrhiza, and mycorrhiza alone), and nitrogen, phosphorus, and potassium (NPK) fertilizers at three different dosages (50%, 75%, and 100% of the recommended amount). The findings revealed that combining HA with mycorrhiza significantly influenced root colonization, with the highest chlorophyll a concentration (1.58 mg g-1) observed in the HA+ mycorrhiza treatment at 75% NPK. This treatment also led to the highest counts in seeds per pod, number of pods, and weight of 100 seeds. Between the 100% and 75% NPK levels in the HA+ mycorrhiza treatment, no significant differences were noted in terms of grain and biological yield. The greatest grain yields were measured at 4356 kg ha-1 and 4322 kg ha-1 for the HA+ mycorrhiza treatment at 100% and 75% NPK, respectively. Additionally, the highest concentrations of Fe, N, P, K, and Zn were observed with the HA+ mycorrhiza application at the 100% NPK level. [ABSTRACT FROM AUTHOR]

Millet is a cereal plant that's potential for rice substitution. This plant is adaptive to be cultivated in dry land but has a tolerance limit to drought stress. Mycorrhiza and phospate (P) fertilizer treatments help plants adapt to this condition. This study aimed to determine the effects of phosphate fertilizer and mycorrhiza as well as their interaction effects on the growth and yield of foxtail millet (Setaria italica L.) under drought stress. The experiment was carried out from January to June 2020 in the experimental farm, Faculty of Agriculture, University of Jenderal Soedirman. The research was arranged in a factorial randomized complete block design consisting of two factors. The first factor was the dose of SP-36 fertilizer per polybag, namely P0 = 0 g, P1 = 37,5 kg.ha-1 (25%), P2 = 75 kg.ha-1 = 0.88 g/polybag (50%), and P3 = 150 kg.ha-1. The second factor was the dose of mycorrhiza biofertilizer, namely M0 = 0 g.polibag-1, M1 = 33.3 g. polibag-1 and M2 = 66.6 g.polybag-1. The treatment was replicated three times. The data observed were analyzed using the F test, continued with DMRT test at p=0.05. The results showed that SP-36 fertilizer application at half of the recommended dose (0.88 g/polybag) could increase growth variables, such as leaf area, panicle length, and seed weight. Mycorrhizae application 33.3 g/polybag could improve variables such as plant height, leaf area, panicle length, and seed weight. It also accelerated the initiation of panicle emergence compared to control. [ABSTRACT FROM AUTHOR]

Orchid mycorrhizal fungi (OMF) are vital biocontrol agents, especially for Odontoglossum ringspot virus (ORSV). The promising study helped identify the mycorrhiza isolate from native tropical orchids and determine its potential as a biocontrol. Sample collection of healthy roots of Phalaenopsis amabilis emanated in Yogyakarta, Indonesia, carrying out molecular identification with rDNA-ITS amplification using a set of universal primers ITS1 and ITS4. In vivo, antagonist tests began by inoculating viruses and mycorrhiza to determine the effect of growth and induction of secondary metabolites. The result showed one isolate of Trichoderma sp. associated with the molecular analysis has amplified the ITS1-5.8S-ITS4 section by 600-750 bp DNA. The sequenced products revealed insertion and substitution occurrences, which may have caused the variance by strain diversity and potential severity. Indonesian isolates have undergone speciation and separation from other isolates by a substantial distance. The considerable effects were the increase in leaf length, leaf width, root length, leaf count, the number of roots, fresh weight, and a lowering of the virus content. The analysis of the plant growth parameters and virus concentrations provided significant differences among the treatments inoculated with orchid mycorrhiza (Mycorrhiza [M], Mycorrhiza + Virus [MV], and Virus + Mycorrhiza [VM]) and those without orchid mycorrhiza inoculation (Control [C] and Virus [V]). The orchid resistance suggested that the virus infecting plant leaves contain more phenolic chemicals. This study is the first-ever report of the Trichoderma sp. isolated from native tropical orchids in Indonesia. [ABSTRACT FROM AUTHOR]

Forests in the northeastern US are experiencing shifts in community composition due to the northward migration of warm-adapted tree species and certain species' declines (for example, white ash and eastern hemlock) due to invasive insects. Changes in belowground fungal communities and associated functions will inevitably follow. Therefore, we sought to investigate the relative importance of two important tree characteristics—mycorrhizal type [ectomycorrhizal (EcM) or arbuscular mycorrhizal (AM)] and leaf habit (deciduous or evergreen) on soil fungal community composition and organic matter cycling. We sampled soil in the organic and mineral horizons beneath two AM-associated (Fraxinus americana and Thuja occidentalis) and two ECM-associated tree species (Betula alleghaniensis and Tsuga canadensis), with an evergreen and deciduous species in each mycorrhizal group. To characterize fungal communities and organic matter decomposition beneath each tree species, we sequenced the ITS1 region of fungal DNA and measured the potential activity of carbon- and nitrogen-targeting extracellular enzymes. Each tree species harbored distinct fungal communities, supporting the need to consider both mycorrhizal type and leaf habit. However, between tree characteristics, mycorrhizal type better predicted fungal communities. Across fungal guilds, saprotrophic fungi were the most important group in shaping fungal community differences in soils beneath all tree species. The effect of leaf habit on carbon- and nitrogen-targeting hydrolytic enzymes depended on tree mycorrhizal association in the organic horizon, while oxidative enzyme activities were higher beneath EcM-associated trees across both soil horizons and leaf habits. [ABSTRACT FROM AUTHOR]

The existing literature on symbioses involving microorganisms is biased towards describing the larger of the partners, even though it is often the microbial partner that determines fitness. It is possible to address size asymmetries between mutualistic partners through the scale-independent parameters, z and c, of species–area relationships (SARs). Some general questions and gaps in understanding which can be addressed with SARs are the spatial scales where spatial aggregation is observed whether SAR parameters are determined by environmental settings, and formulating null expectations for global diversity of endosymbionts. We highlight how SARs can be used to address key questions in arbuscular mycorrhizal symbioses, such as the relationship between fine-scale diversity of fungal symbionts on roots and plant fitness. Symbioses involving microorganisms prevail in nature and are key to regulating numerous ecosystem processes and in driving evolution. A major concern in understanding the ecology of symbioses involving microorganisms arises in the effectiveness of sampling strategies to capture the contrasting size of organisms involved. In many mutualisms, including mycorrhizas and gut systems, hosts interact simultaneously with multiple smaller sized mutualists, the identity of which determines success for the host. This complicates quantifying the diversity of mutualisms because sampling techniques fail to capture effectively the diversity of each partner. Here we propose the use of species–area relationships (SARs) to explicitly consider the spatial scale of microbial partners in symbioses, which we propose will improve our understanding of the ecology of mutualisms. [ABSTRACT FROM AUTHOR]

Soil organic carbon (C) is the largest active C pool of Earth's surface and is thus vital in sustaining terrestrial productivity and climate stability. Arbuscular mycorrhizal fungi (AMF) form symbioses with most terrestrial plants and critically modulate soil C dynamics. Yet, it remains unclear whether and how AMF–root associations (i.e., mycorrhizae) interact with soil minerals to affect soil C cycling. Here we showed that the presence of both roots and AMF increased soil dissolved organic C and reactive Fe minerals, as well as litter decomposition and soil CO2 emissions. However, it reduced mineral‐associated C. Also, high‐resolution nanoscale secondary ion mass spectrometry images showed the existence of a thin coating (0.5–1.0 μm thick) of 56Fe16O− (Fe minerals) on the surface of 12C14N− (fungal biomass), illustrating the close physical association between fungal hyphae and soil Fe minerals. In addition, AMF genera were divergently related to reactive Fe minerals, with Glomus being positively but Paraglomus and Acaulospora negatively correlated with reactive Fe minerals. Moreover, the presence of roots and AMF, particularly when combined with litter addition, enhanced the abundances of several critical soil bacterial genera that are associated with the formation of reactive minerals in soils. A conceptual framework was further proposed to illustrate how AMF–root associations impact soil C cycling in the rhizosphere. Briefly, root exudates and the inoculated AMF not only stimulated the decomposition of litter and SOC and promoted the production of CO2 emission, but also drove soil C persistence by unlocking mineral elements and promoting the formation of reactive minerals. Together, these findings provide new insights into the mechanisms that underlie the formation of reactive minerals and have significant implications for understanding and managing soil C persistence. [ABSTRACT FROM AUTHOR]

Keywords: Glomeromycota; mycorrhizal phenotype; mycorrhizal responsiveness; quantitative synthesis; unusual observations EN Glomeromycota mycorrhizal phenotype mycorrhizal responsiveness quantitative synthesis unusual observations 13 16 4 09/11/23 20231001 NES 231001 Data availability Data are made available in the form of Notes S3 and S4. As an example, we know that plant mycorrhizal growth responses can get negative under very low light availability (Konvalinkova & Jansa, [9]), which describes nonetheless an unusual set of growth conditions in the mycorrhizal literature. Context-dependent plant responses to arbuscular mycorrhiza mainly reflect biotic experimental settings Plant growth stimulation, by contrast, can be observed frequently across experimental settings that include plant pathogens or root-feeding nematodes (Veresoglou & Rillg, [15]). [Extracted from the article]

Background: In rice belts, cultivation of rice under aerobic conditions provides an alternative way to reduce the enormous amounts of water usage, by using 50 percent of the water when compared to traditional cultivation. However, micronutrient deficiencies are more common in aerobic rice during its early stages of growth. Mycorrhizal fungi were found to be efficient in mobilizing the nutrients under aerobic situations. Methods: The field experiment was conducted in Department of Agronomy, Tamil Nadu Agricultural University, Coimbatore. The experiment consisted of thirteen treatments which includes different recommended doses of VAM 50, 62.5 and 75kg ha-1 along with different combinations of foliar application of 0.5% urea, 0.5% ZnSO4 and 1% FeSO4. Result: The study revealed that combined application of 150 % of recommended dose of VAM and foliar application of 0.5% urea + 0.5% ZnSO4 + 1% FeSO4 at 25 and 45 DAS significantly increased the VAM colonization area, photosynthetic pigments and growth parameters such as plant height, shoot and root weight, root growth, leaf area index and yield attributes and it was found to be a better optionin rice cultivation to overcome the micronutrient deficiencies in its earlier stages under aerobic conditions. [ABSTRACT FROM AUTHOR]

The aim of the study was to determine the effect of magnetically treated water (ATM) with a stationary magnetic field on the yield of tomato (Solanum lycopersicum L.) inoculated with three strains of arbuscular mycorrhizal fungi (AMF) infested with the nematode Meloidogyne incognita (Kofoid and White) Chitwood. The investigation began in a soft brown soil without carbonate, in the "Campo Antena" Protected Cultivation Unit, belonging to "América Libre" Socialist State Enterprise; between November 2018 and February 2019. The inoculation of the microorganisms was carried out at the time of the transplant, in a proportion of 10% with respect to the volume of the root ball. The experimental design was completely randomized blocks, with 8 treatments and four replicas, with a control without AMF inoculation, a treatment without AMF inoculation and irrigation with magnetically treated water, 3 treatments with inoculation with Glomus cubense, Rhizophagus irregularis, Fummeliformis mosseae, and 3 treatments with the inoculation of these 3 AMF species combined with irrigation with magnetically treated water with an induction of 0.07 T. The data obtained were processed in the statistical package R Commander by means of a simple analysis of variance, applying Duncan's Test of mean multiple comparison for p= 5. The results obtained showed the efficiency of the treatments applied in tomato yield, highlighting the treatment with G. cubense and ATM, which yielded 112.9 t·ha-1 and provided greater protection to the plant against the nematode attack by reducing the galling index to 1. [ABSTRACT FROM AUTHOR]

Açaí (Euterpe oleracea Mart., Arecaceae), a palm tree native to the Amazon basin, faces problems associated with its initial development, such as uneven germination and slow growth. The objective of this study was to evaluate the initial biometric development of açaí palm seedlings as a function of inoculation, or co-inoculation, with plant growth-promoting microorganisms. The experiment was carried out in a nursery and the treatments consisted of inoculation, or co-inoculation, of seedlings with arbuscular mycorrhizal fungi (Glomus sp. and Gigaspora sp.), diazotrophic bacteria (Azospirillum brasilense) and beneficial microorganisms©, applied in the rhizosphere of the seedlings. At 90 days after sowing, there were no statistical differences between treatments for any of the individual variables. However, hierarchical cluster analysis revealed the existence of four clusters. Shoot height (25.0 cm), leaf insertion height (12.0 cm) and root length (12.1 cm) tended to be slightly lower in non-inoculated seedlings (cluster 1). Inoculation of mycorrhizal fungi tended to promote the best development of seedlings, especially verified through root length (18.3 cm), but forming a cluster with diazotrophic bacteria (cluster 4). On the other hand, co-inoculation of mycorrhizae and diazotrophic bacteria tended to result in the lowest means, especially for shoot dry mass (0.20 mg) (cluster 3). The mix of beneficial microorganisms©, alone or co-inoculated, always formed a single cluster (cluster 2). Inoculation of açaí palm seedlings affects their initial development, but does not promote significant growth and development in a period of 90 days. [ABSTRACT FROM AUTHOR]

The article discusses the current proposals to redefine lichens and highlights the disadvantages of these proposals. Lichens are currently defined as a symbiotic relationship between a fungus (mycobiont) and an alga or cyanobacterium (photobiont). However, some lichen biologists have suggested expanding this definition to include other microorganisms that colonize the lichen thallus. The article argues that these proposals are not justified because the roles and significance of these additional microorganisms are still poorly understood and their inclusion would blur the distinction between lichens and other ecosystems. The article concludes that the current definition of lichens as a partnership between mycobiont and photobiont remains meaningful and should not be amended. [Extracted from the article]

Background: The most common soil-borne diseases in cotton are root rot and wilt, which are caused by Rhizoctonia solani (Taub) Butler and Fusarium oxysporum f. sp. vasinfectum, respectively. These two diseases significantly reduce plant stand and production. Under extreme circumstances, the application of fungicides does not provide satisfactory management of these diseases and also pollutes the environment. The effect of biocontrol agents, their combinations and fungicides on root rot and wilt management and plant growth in Gossypium hirsutum and G. arboreum cultivars CSH-3129 and CICR-3 were studied during 2017–18 and 2018–19. Results: Out of six isolates of Trichoderma spp., T. asperellum (Th-11) was the most effective for inhibiting the mycelial growth of R. solani and F. oxysporum f. sp. vasinfectum (64.4–100%). The combined seed treatment of T. asperellum (Th-11, c.f.u. 2 × 108/g) + Pseudomonas fluorescens (c.f.u. 2 × 108/g) + arbuscular mycorrhizal fungi (AMF; 1200 IP/g) resulted in the highest plant vigour index in CSH-3129 (890.9%) and CICR-3 cultivars (393.5%) at 15 days after treatment. Ninety days after sowing, the combined seed treatments of T. asperellum (Th-11) + P. fluorescens + AMF followed by T. asperellum (Th-11) + P. fluorescens showed the lowest area under the disease progress curve in CICR-3 and CSH 3129. Two-year pooled results indicated that the combined seed treatment with T. asperellum (Th-11) + P. fluorescens + AMF reduced the root rot disease by 51 and 57.5% in CICR-3 and CSH-3129 cultivars, respectively, under field conditions. Conclusion: The present investigation suggested that combined application of the most effective strains of T. asperellum (Th-11) @10 g/kg + P. fluorescens @10 g/kg and AMF @20 g/kg can effectively manage root rot and wilt diseases up to 60 days after sowing and enhance plant growth under field conditions. However, the application rates of these biocontrol agents vis-à-vis load of pathogen inoculum in the field must be further evaluated for improved and long-term effects. [ABSTRACT FROM AUTHOR]

Root systems of most land plants are colonised by arbuscular mycorrhiza fungi. The symbiosis supports nutrient acquisition strategies predominantly associated with plant access to inorganic phosphate. The nutrient acquisition is enhanced through an extensive network of external fungal hyphae that extends out into the soil, together with the development of fungal structures forming specialised interfaces with root cortical cells. Orthologs of the bHLHm1;1 transcription factor, previously described in soybean nodules (GmbHLHm1) and linked to the ammonium facilitator protein GmAMF1;3, have been identified in Medicago (Medicago truncatula) roots colonised by AM fungi. Expression studies indicate that transcripts of both genes are also present in arbuscular containing root cortical cells and that the MtbHLHm1;1 shows affinity to the promoter of MtAMF1;3. Both genes are induced by AM colonisation. Loss of Mtbhlhm1;1 expression disrupts AM arbuscule abundance and the expression of the ammonium transporter MtAMF1;3. Disruption of Mtamf1;3 expression reduces both AM colonisation and arbuscule development. The respective activities of MtbHLHm1;1 and MtAMF1;3 highlight the conservation of putative ammonium regulators supporting both the rhizobial and AM fungal symbiosis in legumes. [ABSTRACT FROM AUTHOR]

Summary: Stable isotope signatures of fungal sporocarps have been instrumental in identifying carbon gains of chlorophyllous orchids from a fungal source. Yet, not all mycorrhizal fungi produce macroscopic sporocarps and frequently fungi of different taxa occur in parallel in orchid roots.To overcome this obstacle, we investigated stable isotope signatures of fungal pelotons extracted from orchid roots and compared these data to the respective orchid and reference plant tissues. Anoectochilus sandvicensis and Epipactis palustris represented specialized or unspecialized rhizoctonia‐associated orchids. Epipactis atrorubens and Epipactis leptochila are orchids considered ectomycorrhiza‐associated with different preferences for Basidio‐ and Ascomycota.13C enrichment of rhizoctonia pelotons was minor compared with plant tissues and significantly lower than enrichments of pelotons from ectomycorrhizal Epipactis species. 15N values of pelotons from E. leptochila and E. atrorubens showed similar patterns as known for respective sporocarps of ectomycorrhizal Ascomycota and Basidiomycota, however, with an offset towards lower 15N enrichments and nitrogen concentrations.Our results suggest an explicit fungal nutrition source of orchids associated with ectomycorrhizal fungi, whereas the low 13C enrichment in rhizoctonia‐associated orchids and fungal pelotons hamper the detection of carbon gains from fungal partners. 15N isotopic pattern of orchids further suggests a selective transfer of 15N‐enriched protein‐nitrogen into orchids. [ABSTRACT FROM AUTHOR]

Soil functioning is closely linked to the interactions between biological communities with the physical environment. Yet, the impact of plant community attributes on metabolic processes promoting soil nutrient cycling remains largely unknown. We hypothesized that the plant community acts as a regulating agent of nutrient mobilization in soils according to the phylogenetic and morpho-functional traits of plant species of which it is composed. Rhizosphere soils were collected in autumn and spring under 32 tree and shrub species in two Mediterranean mixed forests (four plots in each) located in southern Spain, and nine soil enzymatic activities related to C, N and P mobilization were assessed. Phylogeny and morpho-functional traits of plant species were recorded and their imprint in soil enzymatic activities across forests was determined. The results showed a plant phylogenetic signal for N mobilization in both forests, while it varied across forests for non-labile C and P mobilization. The plant phylogenetic signals were primarily driven by lineages that diversified through the Miocene, about 25 Myr ago. In addition, leaf traits and plant's mycorrhizal type explained soil enzymatic activities independently from phylogeny. C and P mobilization increased under ectomycorrhizal plants, whilst enhanced N mobilization did occur under arbuscular mycorrhizal ones. The plant community composition led to a different carbon and nutrient mobilization degree, which in turn was mediated by distinct microbial communities mirroring differentiated resource-acquisition strategies of plants. Our results highlight the role of plant traits and mycorrhizal interactions in modulating carbon and nutrient cycling in Mediterranean mixed forest soils. [ABSTRACT FROM AUTHOR]

A field experiment was conducted to investigate the effect of biochar, organic matter (hundz soil) and mycorrhiza on soil hydrophysical properties, irrigation water applied and water productivity of soybean crop in arid soils. The treatments included eight practices i.e., control (C), 15 t ha–1 biochar (B), 15 t ha–1 hundz soil (H), 2.5 kg ha–1 mycorrhiza (M), 15 t ha–1 B + 2.5 kg ha–1 M (B + M), 15 t ha–1 H + 2.5 kg ha–1 M (H + M), 7.5 t ha–1 B + 7.5 kg ha–1 H (50% B + 50% H) and 7.5 t ha–1 B + 7.5 t ha–1 H + 2.5 kg ha–1 (50% B + 50% H + M). The results observed that there is a significant decrease in soil bulk density at the mixture of B, H and M. Also, a significant increase in soil porosity and hydraulic conductivity were recorded. The reduction of actual evapotranspiration (ETa) and irrigation water applied (IWA) by the treatments could be set in the descending order: 50% B + 50% H + M > 50% B + 50% H > H + M > B + M > H > B > M > C. The highest relative decrease (mean of both seasons) of ETa and IWA were 25.98% and 23.46%, respectively at 50% B + 50% H + M treatment. Also, crop water productivity and irrigation water productivity were significantly (P ≤ 0.05) increased as compared to control. Plant height, seed index, seed yield, portion content and oil content were significantly (P ≤ 0.05) increased as a result applying of B, H and M. The results imply that the mixture of biochar, hundz soil and treated soybean seed with mycorrhiza are considered a valuable approach to improve soil hydrophysical properties, water productivity and soybean yield in arid regions. [ABSTRACT FROM AUTHOR]