Application Of Arbuscular Mycorrhizal Fungi Research Articles

Evaluation of mycorrhizae transplantation from Panicum maximum as biofertilizer for paddy cultivation in Sri Lanka

Indiscriminate chemical fertilization in paddy fields is causing detrimental global impacts, therefore exploration of bio-based sustainable alternatives to compensate requirement of chemical fertilizers is necessary. This study was designed to evaluate use of Arbuscular Mycorrhizal Fungi (AMF) obtained from roots of a spontaneous weed grass (Panicum maximum), which demonstrated an average AMF root colonization of 75-85%, as self-produced biofertilizer for rice cultivation. Field trial was carried out in paddy field at Monaragala, Sri Lanka. Two traditional rice (Oriza sativa L.) varieties (Suwadel and Kuruluthuda) were selected, and Randomized Complete Block Design was employed with three replicates in eight different treatment plots per block. Different chemical fertilizer regimes (100%, 50% and 25% of recommended fertilizer dose) and no amendments as controls were applied. AMF inocula were applied alone or supplemented to fertilized treatments (100% +AMF, 50% +AMF, 25% +AMF, AMF alone). Treatment plan was implemented separately for two varieties. Rice yield and percentage of AMF root colonization were quantified at harvest. Results revealed that grain dry weight for Suwadel was significantly higher (p<0.05) in treatments supplying AMF in addition with chemical fertilizer at optimal dose (100%) or 50% reduced, compared to other treatments. Highest number of seeds was observed in plants treated with 100% fertilizer, but result was not significantly different (p>0.05) from 50% +AMF and 100% + AMF treatments. Treatments with AMF inocula alone showed highest percentages of AMF colonization in Suwadel. Inverse connection was observed between fertilizer level and AMF colonization. Differently from Suwadel, no AMF colonization was observed in Kuruluthuda variety and no significant differences were observed in harvest for treatments with and without AMF application. According to results, usage of AMF inocula as on-field prepared biofertilizer combined with 50% of chemical fertilizer is effective in improving sustainable agriculture but efficacy of application strictly depends on crop variety.

Fullerenol nanoparticles and AMF application for optimization of Brassica napus L. resilience to lead toxicity through physio-biochemical and antioxidative modulations

Crop plants are severely affected by heavy metals (HMs), leading to food scarcity and economical loss. Lead (Pb) is outsourced by use of lead-based fertilizers, batteries, mining, smelting and metal processing. It significantly reduces growth, development and yield of crops cultivated on contaminated sites. In this study, the ameliorative role of carbon based fullerenol nanoparticles (FNPs) in combination with Arbuscular Mycorrhizal Fungi (AMF) inoculation was examined in Brassica napus L. grown in Pb contaminated soil. A pot experiment in three-ways completely randomize fashion with three replicates was conducted. For Pb stress, a 200 µM PbCl2 solution was applied at a rate of 1 L per pot. FNPs were applied via foliar spray at a concentration of 3 mM. For AMF inoculation rhizospheric soil was collected from Sorghum bicolor fields and used in this experiment. Results of the study showed that Pb toxicity greatly reduced growth (shoot length; 15%, root length; 25%) of B. napus plants. It lowered photosynthesis (38%) and gas exchange related attributes. Pb contamination caused oxidative stress, evident from elevated level of malondialdehyde (62%), and reactive oxygen species (H2O2; 60%, OH−; 103% and O2•−; 23%). It also triggered the antioxidant defense system of B. napus. These plants also had high Pb metal ions in their root and shoot compared with control. Foliar application of FNPs along with AMF inoculation effectively mitigated oxidative stress caused by Pb via increasing antioxidant enzymes activities. Catalase, peroxidase, superoxide dismutase, ascorbate peroxidase, glutathione reductase, phenylalanine ammonia-lyase and polyphenol peroxidase activities were increased by 37, 19, 96, 200, 47, 117 and 47%, respectively. In conclusion, these treatments modulated photosynthetic machinery, antioxidant defense mechanism and nutrients uptake in B. napus plants to alleviate Pb stress. It is presumed that use of carbon-based nano particles in combination with AMF inoculation could effectively mitigate HMs stress in crop plants grown in contaminated soil.

The role of vermiwash and mycorrhiza in enhancing organic head lettuce production

ABSTRACT The study aimed to enhance the organic production of head lettuce using vermiwash and arbuscular mycorrhizal fungi (AMF), both individually and in combination, in the presence of compost. These treatments were evaluated for their effects on the growth, yield, quality and mineral content of head lettuce, compared to a control treatment of compost only. The results showed that all treatments involving vermiwash and AMF, either individually or together, significantly improved growth, yield and quality over compost alone. The combination of vermiwash and AMF with compost yielded the best results across all measured parameters. This study recommends using vermiwash and AMF together with compost as an effective approach to improving organic head lettuce production, which will increase profits for organic lettuce growers. HIGHLIGHTS Vermiwash and AMF combined with compost significantly enhanced head lettuce growth and yield. The application of vermiwash and AMF led to better quality and mineral content in lettuce compared to compost-only treatment. The combination of vermiwash and AMF together outperformed their individual applications, showing a synergistic effect. The use of organic treatments (compost, vermiwash and AMF) aligns with sustainable agricultural practices. This study advocates for the combined use of vermiwash and AMF with compost to optimise organic head lettuce production.

Mitigating Chili Plant Wilt: Synergy of Arbuscular Mycorrhizal Fungi and Silver Nanoparticles

Background/Objective. The chilaca pepper (Capsicum annuum) is significantly impacted by the attack of the oomycete Phytophthora capsici, which causes chili wilt. Current methods for controlling this disease have been inefficient. Therefore, the search for more environmentally friendly alternatives is of great importance. In pursuit of this objective, we assessed the potential of arbuscular mycorrhizal fungi (AMF) and silver nanoparticles (AgNPs) to try to reduce or postpone chili pepper wilt. Materials and Methods. Growth parameters were measured in inoculated and non-inoculated chili pepper plants with AMF from a commercil consortium TM-73 (Biotecnología Microbiana) and the protective effects of AMF and AgNPs (NanoID®) against P. capsici as evaluated using a severity scale for wilt symptoms. Plant response to pathogen infection was assessed by measuring the activities of antioxidant enzymes: PER, SOD, CAT and H2O2. Results. The results indicated that AMF application improved the growth parameters of C. annuum, while the plant-pathogen interaction induced an antioxidant enzymatic response. AMF maintained wilt symptoms at or below 80%, preventing plant death. Meanwhile, AgNPs (50ppm) delayed plant mortality compared to the control treatment. Conclusion. The combined use of AMF and AgNPs offer options for future research in the disease management for chili peppers.

Garlic stalk waste and arbuscular mycorrhizae mitigate challenges in continuously monocropping eggplant obstacles by modulating physiochemical properties and fungal community structure

Background and aimsContinuous vegetable production under plastic tunnels faces challenges like soil degradation, increased soil-borne pathogens, and diminished eggplant yield. These factors collectively threaten the long-term sustainability of food security by diminishing the productivity and resilience of agricultural soils. This research examined the use of raw garlic stalk (RGS) waste and arbuscular mycorrhizal fungi (AMF) as a sustainable solution for these issues in eggplant monoculture. We hypothesized that the combined application of RGS waste and AMF would improve soil physicochemical properties compared to untreated soil in eggplant monoculture. The combined use of RGS and AMF was expected to suppress soil-borne pathogens, increase the abundance of soil beneficial microorganisms and alter fungal community structure. The combined application of RGS and AMF will significantly enhance eggplant yield compared to untreated plots. This study aimed to determine whether AMF and RGS, individually or in combination, can ameliorate the adverse effects of monoculture on eggplant soil. We also investigated whether these treatments could enhance eggplant yield.MethodsThe experiment was arranged in a completely randomized design with four treatments: AMF, RGS, and a combined treatment of AMF + RGS (ARGS), along with a control. Each treatment was replicated three times, Eggplant seedlings inoculated with AMF and treated with RGS amendments, both individually and combined. The effects on root traits, soil physicochemical properties, soil enzyme activity, and fungal community structure were investigated.ResultsRGS amendments and AMF inoculation improved root length, volume, and mycorrhizal colonization. The combined treatment showed the most significant improvement. RGS and AMF application increased soil nutrient availability (N, P, K) and organic matter content. Enzyme activities also increased with RGS and AMF treatments, with the combined application showing the highest activity. Soil electrical conductivity (EC) increased, while soil pH decreased with RGS and AMF amendments. Sequencing revealed a shift in the fungal community structure. Ascomycota abundance decreased, while Basidiomycota abundance increased with RGS and AMF application. The combined treatment reduced the abundance of pathogenic genera (Fusarium) and enriched beneficial taxa (Chaetomium, Coprinellus, Aspergillus). Pearson correlations supported the hypothesis that soil physicochemical properties influence fungal community composition.ConclusionsThis study demonstrates the potential of co-applying RGS and AMF in continuous cropping systems. It enhances soil physicochemical properties, reduces soil-borne pathogens, and promotes beneficial microbial communities and eggplant yield. This combined approach offers a sustainable strategy to address the challenges associated with eggplant monoculture under plastic tunnels.

EFFECT OF MUNICIPAL SOLID WASTE COMPOST, GYPSUM AND MYCORRHIZA ON METALS CONTENT IN SOIL AND PEANUT GRAIN

Municipal solid waste compost (MSWC) is widely used as an organic soil amendment and fertilizer on agricultural land. However, applying MSWC can cause adverse effects due to the heavy metals contained. This study aimed to determine the heavy metal content of MSWCs in the presence of mycorrhizae and gypsum and their effects on soil and peanut grain. The field experiment was conducted using a split factorial design based on a Randomized Complete Block Design (RCBD) with three replications in Iran during 2018 and 2019. The main factor includes two levels of gypsum (0 and 150 kg ha-1) and the sub-factors include the presence and absence of Arbuscular mycorrhizal fungi (AMF) and different levels of MSWC at five levels (0, 2, 4, 6, and 8 t ha-1). The findings showed that MSWC significantly increased the concentrations of manganese (Mn), lead (Pb), nickel (Ni), zinc (Zn), cobalt (Co), chromium (Cr), cadmium (Cd), and boron (B) in soil and grains. In addition, Co, Ni, and Zn concentrations in grain increased and Pb, Mn, Ni, and Zn concentrations in soil decreased with AMF application. Gypsum treatment also had no significant effect on metals in both grain and soil. According to the obtained results, the use of 4 t ha-1 of MSWC along with mycorrhiza in peanut cultivation is suggested in order to reduce the environment risks of soil and plants cause by the use of compost, and also use the benefits of urban waste compost.

Application of Arbuscular Mycorrhizal Fungi for Improved Growth and Acclimatization of Micropropagated Fegra Fig (Ficus palmata Forssk.) Plantlets

Fegra fig (Ficus palmata) is an important fruit-yielding crop and potential rootstock for grafting Ficus carica. The acclimatization phase is a pivotal step during the micropropagation of plants. During this study, the mycorrhization of micropropagated fegra fig plants with two arbuscular mycorrhizal fungi (AMF; Gigaspora margarita and Gigaspora albida) to enhance their growth and survival during the acclimatization stage was investigated. The AMF were mixed in equal proportions and the acclimatizing fegra fig plantlets were treated for 8 weeks. The leaf pigments, i.e., chlorophyll a [2.56 mg·g−1 fresh weight (FW)], chlorophyll b (1.08 mg·g−1 FW), total chlorophyll (3.67 mg·g−1 FW), and carotenoid (1.34 mg·g−1 FW), of AMF-treated plants were higher than those of non-AMF plants. The number of stomata per unit was higher in the AMF-treated plants (16.00), the density of stomata per unit area (88.40 mm2) of AMF-treated plants was similar to that of non-AMF treated plants, and the number of epidermal cells (79.00) was higher in the AMF-treated plants. The AMF-treated plants were taller and had more leaves, a greater leaf area, and higher shoot FW and dry weight. The AMF-treated plants also had the greatest total root length values, greatest surface areas of roots, and greatest total root volume and diameter compared to those of non-AMF plants. Additionally, the AMF-treated plants had a 100% survival rate, whereas a survival rate of 95% was recorded for non-AMF plants. These findings emphasize the importance of biological acclimatization of micropropagated fegra fig plants with AMF.

Arbuscular mycorrhizal symbiosis enhances the accumulation of plant-derived carbon in soil organic carbon by regulating the biosynthesis of plant biopolymers and soil metabolism

Plant-derived carbon (C) is a critical constituent of particulate organic carbon (POC) and plays an essential role in soil organic carbon (SOC) sequestration. Yet, how arbuscular mycorrhizal fungi (AMF) control the contribution of plant-derived C to SOC storage through two processes (biosynthesis of plant biopolymers and soil metabolism) remains poorly understood. Here, we utilized transcriptome analysis to examine the effects of AMF on P. communis roots. Under the AM symbiosis, root morphological growth and tolerance to stress were strengthened, and the biosynthetic pathways of key plant biopolymers (long-chain fatty acids, cutin, suberin, and lignin) contributing to the plant-derived C were enhanced. In the subsequent metabolic processes, AMF increased soil metabolites contributing to plant-derived C (such as syringic acid) and altered soil metabolic pathways, including carbohydrate metabolism. Additionally, C-acquiring soil extracellular enzyme activities were enhanced by AMF, which could affect the stabilization of plant-derived C in soil. The contents of POC (21.71 g kg−1 soil), MAOC (10.75 g kg−1 soil), and TOC (32.47 g kg−1 soil) in soil were significantly increased by AMF. The concentrations of plant-derived C and microbial-derived C were quantified based on biomarker analysis. AMF enhanced the content of plant-derived C in both POC and MAOC fractions. What's more, plant-derived C presented the highest level in the POC fraction under the AMF treatment. This research broadens our understanding of the mechanism through which plant-derived C contributes to the accumulation of POC and SOC induced by AM symbiosis, and evidences the benefits of AMF application in SOC sequestration.

Isolation, trapping, and application of arbuscular mycorrhizal fungi to increase of phosphorus efficiency, growth, and productivity of soybean under saturated soil culture on acid sulphate soil

Isolation, trapping, and application of arbuscular mycorrhizal fungi to increase of phosphorus efficiency, growth, and productivity of soybean under saturated soil culture on acid sulphate soil

Mitigation of microplastic toxicity in soybean by synthetic bacterial community and arbuscular mycorrhizal fungi interaction: Altering carbohydrate metabolism, hormonal transduction, and genes associated with lipid and protein metabolism

Microplastics (MPs) have become ubiquitous environmental pollutants, eliciting concerns about their negative impacts on terrestrial and agroecosystems. However, employing sustainable remediation approaches holds the potential to mitigate these negative impacts and bolster MPs tolerance in both the seeds and vegetative structures of plants. The current investigation explores the impact of arbuscular mycorrhizal fungi (AMF) and synthetic bacterial community (SynCom) as potential alleviators of MP-induced stress. Results exhibited that co-applied SynCom and AMF, resulted in the highest plant biomass, leaf area, pod per plant, and 100-seed weight under control (no MPs) and MPs stress. The combined application of SynCom and AMF enhanced colonization, association, and arbuscule abundance in the non-stressed plants (no MPs) as compared to stressed plants. The sole or co-application of SynCom and AMF enhanced the primary metabolites content and mitigated the MPs-induced reduction in soluble sugars, lipids, protein, and oil contents. Soybean inoculation stimulated the genes expression involved in lipid and protein biosynthesis, while a contradictory drift was noted for genes associated with lipid and protein degradation, underpinning the observed increment in protein and lipid content. Soybean inoculated with AMF exhibited the utmost α-amylase and β-amylase activities, demonstrating enhanced osmolyte (soluble sugar) production, mainly under MPs stress. Remarkably, sole or co-application further reinforces the positive effect of MPs stress on the osmoprotectants and antioxidant levels, for instance, phenol, flavonoid, glycine betaine contents, and glutathione-S-transferase (GST) activities. Subsequent to the stress release, a stress hormones known as abscisic acid (ABA) reduced in the seeds of inoculated soybean while gibberellin (GA), trans-zeatin riboside (ZR), and indole acetic acid (IAA) were increased. Therefore, it is concluded that the combined application of SynCom and AMF protected the soybean plants from MPs-induced oxidative damage by upregulating osmoprotectants and antioxidant levels. This study provides insights into the potential of sustainable remediation approaches in alleviating the complex impact of MPs on soybean, contributing to future strategies for environmental sustainability. Future studies could explore the optimization of SynCom and AMF formulations for different crops and environmental conditions, potentially leading to practical applications in sustainable agriculture and pollution management.

Impact of Poultry Manure-Derived Biochar and Bio-Fertilizer Application to Boost Production of Black Cumin Plants (Nigella sativa L.) Grown on Sandy Loam Soil

Biochar derived from poultry manure increases nutrient availability and promotes plant growth. This study investigated the effect of biochar with mycorrhizal and/or plant growth-promoting rhizobacteria on soil fertility, chemical properties, oil, and seed yield of Black Cumin (Nigella sativa L.) plants. A split-plot design with three replicates was employed, with biochar derived from poultry litter (BC) applied at rates of 0, 5, and 10 t ha−1, with beneficial microbes such as arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) affecting the growth of Black Cumin plants, and some soil properties, such as pH, electrical conductivity (EC), soil organic matter (SOM) and fertility index (FI), showing significant differences (p ≤ 0.05) among biochar and/or bio-fertilizer treatments. All biochar treatments with or without bio-fertilizers significantly increased pH, EC, OM and FI in comparison to the control treatment. The results demonstrated that applying biochar at the highest rate (10 t ha−1) increased fresh and dry capsule weights by 94.51% and 63.34%, respectively, compared to the control treatment (C). These values were significantly increased by 53.05 and 18.37%, compared to untreated plants when combined with AMF and PGPR. Furthermore, when biochar was applied in conjunction with both AMF and PGPR, fresh and dry capsule weights saw significant increases of 208.84% and 91.18%, respectively, compared to the untreated control treatment. The interaction between biochar, AMF, and PGPR significantly improved plant growth, yield, soil properties, and the fixed and volatile oil content of Black Cumin. These findings suggest that the combined application of biochar, AMF, and PGPR enhances nutrient availability and uptake, leading to improved growth and higher yields in Black Cumin plants, resulting in increased yield production.

Utilization of Arbuscular Mycorrhizal Fungi for the Efficiency Development of Lead (Pb) Metal Absorption and Growth of Hanjuang Plants (Cordyline fruticosa)

Contamination of Pb metal into the soil is an environmental problem that has a serious impact on living things, so it needs to be addressed through phytoremediation, one of which is using hanjuang plants. Plant roots in symbiosis with arbuscular mycorrhizal fungi (AMF) can increase plant growth and the phytoremediation ability of plants growing in polluted soil. This research aims to determine the effect of AMF application on the growth of hanjuang plants and the ability of hanjuang roots to absorb Pb metal. The research design used a single treatment with a Completely Randomized Block Design (CRBD) of 4 doses of AMF with 6 replications, namely control; 10 g polybag-1; 20 g polybag-1; and 30 g polybag-1. Planting was carried out for 8 weeks to see the growth and planting of hanjuang and the efficiency of Pb absorption in plant roots. The results showed that AMF had a significant effect on plant height aged 5 to 8 weeks, plant biomass, root wet weight, and root dry weight, but had no significant effect on the efficiency of Pb absorption in the roots of hanjuang plants. An AMF dose of 30 g polybag-1 provides the best results for the growth of hanjuang plants.

Synergism or Antagonism: Do Arbuscular Mycorrhizal Fungi and Plant Growth-Promoting Rhizobacteria Work Together to Benefit Plants?

In agriculture, abiotic and biotic stress reduce yield by 51–82% and 10–16%, respectively. Applications of biological agents such as plant growth-promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) can improve plant growth. Applications of lone PGPR and AMF also help plants resist abiotic and biotic stressors. The reports for dual inoculation of AMF and PGPR to benefit plants and tackle stressors are largely unknown. It is speculated that PGPR colonization in plants enhances AMF infection during dual AMF and PGPR application, although increased AMF colonization does not always correlate with the increased benefits for the plant hosts. Further research is needed regarding molecular mechanisms of communication during dual inoculations, and dual-inoculation enhancement of induced systemic resistance under pathogen stress, to understand how dual inoculations can result in enhanced plant benefits. The influence of application timing of AMF and PGPR dual inoculations on mitigating abiotic and biotic stress is also not well understood. This review documents the factors that govern and modulate the dual application of AMF and PGPR for plant benefits against stress responses, specifically abiotic (drought) stress and stress from pathogen infection.

The legacy effects of mycorrhizal fungal inoculation alleviate soil nitrogen limitations by modulating the homeostasis of extracellular enzymes and fungal function in arid mining regions

AbstractRe‐vegetation types and the application of arbuscular mycorrhizal fungi (AMF) play a crucial role in regulating soil conditions and enhancing vegetation cover during ecological restoration in the northern arid mining area. However, the impact of AMF on the balance of soil–plant–microbial ecosystems through its influence on microbial activities remains unclear. Therefore, we studied the influence of AMF on soil nutrient limitation and the soil fungal community in five different vegetation types in the Daliuta reclamation area. Through the measurement of soil extracellular enzyme activity and the analysis of soil fungal communities by high‐throughput sequencing, we found that the ratio of lnBG:ln(NAG + LAP):lnAP in the AMF sample was closer to 1:1:1, and the soil ecological enzyme stoichiometry was more balanced. The results of enzyme vector showed that AMF inoculation could alleviate the restriction of soil nitrogen nutrients. The results of high‐throughput sequencing showed that AMF improved the diversity of soil fungal community by regulating the composition of soil fungal community, and finally alleviated the nitrogen restriction during decomposition. Functional prediction of soil fungi using FUNGuild indicated that the soil fungi present were mainly saprophytic, saprophytic–symbiotic, and pathotroph–saprophytic–symbiotic trophic types. AMF reduced the percentage of pathotroph fungi and also tended to transform saprophytic into saprophytic–symbiotic type. The findings suggest that mycorrhizal reclamation can enhance the homeostasis of extracellular enzyme dynamics by optimizing fungal community structure and modulating fungal functionality, thereby alleviating microbial nutrient constraints and improving plant adaptability to arid environments. This article provides a theoretical underpinning for eco‐friendly mining construction and sustainable ecological development in arid mining areas.

Arbuscular mycorrhizal fungi affected soft wheat quality properties and nutritional index by regulating the composition and secondary structure of protein

Arbuscular mycorrhizal fungi (AMF) inoculation has important regulatory influence on plant growth and nitrogen uptake, which are intimately associated with soft wheat yield and quality. The study aimed to investigate the impact of AMF inoculation on soft wheat grain yield, protein compositions, protein quality, secondary structure of gluten, dough properties and biscuits baking quality. In this study, AMF inoculation significantly increased grain yield. AMF inoculation decreased grain protein content by 5.1%, glutenin content by 8.5%, GMP by 14.3%, and HMW-GS by 8.8% compared with CK. Conversely, AMF inoculation increased the ratio of gliadin/glutenin. Further analysis showed AMF treatment had a looser gluten network than CK, significantly reduced β-sheet and β-turn content, while α-helix content increased. The nutritional index of grain protein was slightly reduced under AMF inoculation, yet the biological value was improved. Reduced wet gluten content, gluten performance index and dough development time under AMF treatment through regulation of soft wheat protein composition and gluten protein structure. Therefore, biscuits in AMF treatment showed reduced thickness, hardness, significantly greater spread ratio and sensory score compared with CK. These indicate that AMF application would be a beneficial agronomic practice to synergistically optimize yield and grain quality in soft wheat.

Effects of Vermicast and Arbuscular Mycorrhizal Fungi (AMF) on the Establishment of Cacao (Theobroma cacao Linn.) Seedlings Grown in Degraded Soil

Declining soil fertility poses a significant challenge for cacao production, particularly for establishing seedlings. This study investigated the potential effects of vermicast and arbuscular mycorrhizal fungi (AMF) to enhance cacao seedling establishment in degraded soil conditions. The study was conducted in a low-cost protective structure established at the Abaca Project Experimental Area of the University of Southeastern Philippines, Mampising, Mabini, Davao de Oro, from December 2018 to April 2019. Furthermore, a Completely Randomized Design (CRD) was employed with eight (8) treatments and three (3) replications with eight (8) sample plants per replicate. The following are the treatment combinations: No Application (T1), Recommended Rate (T2), Vermicast (T3), AMF (T4), Vermicast + AMF (T5), Recommended Rate + AMF (T6), Recommended Rate + Vermicast (T7), and Recommended Rate + AMF + Vermicast (T8). The results of the study reveal that the application of vermicast and AMF combined with inorganic fertilizer based on the recommended rate increased the growth and development of cacao seedlings in degraded soil in terms of plant height (16.40%), length of leaves (14.59%), the width of leaves (12.11%), number of leaves (1.26%), leaf color (41%), stem diameter, shoot weight (60%), dry matter yield (116%) and root:shoot ratio (63.16%) compared to control or no application. Thus, the judicious use of inorganic fertilizer, vermicast, and AMF improves the establishment of cacao seedlings in soils with degraded conditions.

Genome-wide transcriptome and gene family analysis reveal candidate genes associated with potassium uptake of maize colonized by arbuscular mycorrhizal fungi

BackgroundPotassium (K) is an essential nutrient for plant growth and development. Maize (Zea mays) is a widely planted crops in the world and requires a huge amount of K fertilizer. Arbuscular mycorrhizal fungi (AMF) are closely related to the K uptake of maize. Genetic improvement of maize K utilization efficiency will require elucidating the molecular mechanisms of maize K uptake through the mycorrhizal pathway. Here, we employed transcriptome and gene family analysis to elucidate the mechanism influencing the K uptake and utilization efficiency of mycorrhizal maize.Methods and resultsThe transcriptomes of maize were studied with and without AMF inoculation and under different K conditions. AM symbiosis increased the K concentration and dry weight of maize plants. RNA sequencing revealed that genes associated with the activity of the apoplast and nutrient reservoir were significantly enriched in mycorrhizal roots under low-K conditions but not under high-K conditions. Weighted gene correlation network analysis revealed that three modules were strongly correlated with K content. Twenty-one hub genes enriched in pathways associated with glycerophospholipid metabolism, glycerolipid metabolism, starch and sucrose metabolism, and anthocyanin biosynthesis were further identified. In general, these hub genes were upregulated in AMF-colonized roots under low-K conditions. Additionally, the members of 14 gene families associated with K obtain were identified (ARF: 38, ILK: 4, RBOH: 12, RUPO: 20, MAPKK: 89, CBL: 14, CIPK: 44, CPK: 40, PIN: 10, MYB: 174, NPF: 79, KT: 19, HAK/HKT/KUP: 38, and CPA: 8) from maize. The transcript levels of these genes showed that 92 genes (ARF:6, CBL:5, CIPK:13, CPK:2, HAK/HKT/KUP:7, PIN:2, MYB:26, NPF:16, RBOH:1, MAPKK:12 and RUPO:2) were upregulated with AM symbiosis under low-K conditions.ConclusionsThis study indicated that AMF increase the resistance of maize to low-K stress by regulating K uptake at the gene transcription level. Our findings provide a genome-level resource for the functional assignment of genes regulated by K treatment and AM symbiosis in K uptake-related gene families in maize. This may contribute to elucidate the molecular mechanisms of maize response to low K stress with AMF inoculation, and provided a theoretical basis for AMF application in the crop field.

Biochar and arbuscular mycorrhizal fungi promote rapid-cycling Brassica napus growth under cadmium stress

Purpose: To explore the mechanisms of tolerance of Brassica napus to ultra-high concentration cadmium pollution and the synergistic effects of biochar (BC) and Arbuscular mycorrhizal fungi (AMF) on plant growth under cadmium (Cd) stress. Results: The application of 5 % BC and inoculation with 10 g AMF significantly promoted the growth and development of B. napus. The combined application of BC and AMF (BC1A and BC2A) was better than the single application. At the Cd 200 mg/kg level, BC1A increased the fresh weight and Cd content of the above-ground parts of B. napus by 35.5 % and decreased by 21.20 %. The SOD and POD activities increased by 30.63 % and 73.37 %. The MDA and H2O2 contents decreased by 40.8 % and 69.99 %, soluble sugar content increased by 37.96 %. At the Cd 300 mg/kg level, BC1A increased the fresh weight and Cd content of the above-ground parts of B. napus by 32.8 % and decreased by 15.99 %. The SOD and POD activities increased by 39.06 % and 93.56 %. The MDA and H2O2 contents decreased by 28.39 % and 72.45 %, and the soluble sugar content increased by 21.16 %. Overall, both BC and AMF treatments alone or in combination (BC1A) were able to alleviate Cd stress and promote plant growth, with the combination of biochar and AMF being the most effective. Furthermore, transcriptome analyses indicated that BC may improve cadmium resistance in B. napus by significantly up-regulating the expression of genes related to peroxidase, photosynthesis, and plant MAPK signaling pathways. AMF may alleviate the toxicity of Cd stress on B. napus by up-regulating the expression of genes related to peroxisomes, phytohormone signaling, and carotenoid biosynthesis. The results of the study will provide support for ecological restoration technology in extremely heavy metal-polluted environments and provide some reference for the application and popularization of BC and AMF conjugation technology.

Combined inoculation of arbuscular mycorrhiza fungi with Meso‐rhizobium improves nutrient uptake, growth performance, and moisture stress tolerance of chickpea (Cicer arietinum L.)

AbstractBiofertilizers can be better alternatives to chemical fertilizers to enhance plant nutrition and productivity as they improve the soil fertility and crop productivity in an eco‐friendly and cost‐effective manner. A pot experiment was conducted between December 2018 and March 2019 in southern Ethiopia to evaluate the combined inoculation of arbuscular mycorrhizal fungi (AMF) and Meso‐rhizobium (MR) on biomass yield, nutrient uptake, and moisture stress tolerance of chickpea (Cicer arietinum L.) (variety: Habru). The experiment was executed as a factorial arrangement using a completely randomized design with three replications. The treatments were control (non‐fertilized), sole AM fungi inoculation, AM fungi inoculation with phosphorus fertilizer (20 kg P ha−1) and MR, and sole inorganic fertilizers (20 kg P;10 kg N ha−1) at four different moisture levels (optimum throughout the growing season, stressed at vegetative, flowering, and seed filling stages). The results demonstrated that biomass yields were limited by moisture stress, especially at vegetative and flowering stages of chickpea. Sole and co‐application of AMF with MR and inorganic P increased biomass yields on average by 19%, 39%, and 33% under water stress conditions, respectively, compared to the non‐inoculated control. The application of AMF with MR and inorganic P also significantly increased nodulation, AMF colonization, and nutrient uptake, but these effects were dependent on soil moisture status. In conclusion, there are potential advantages to be gained from sole and combined AMF application with rhizobium to improve growth and productivity of chickpea through enhanced nutrient and water uptake, though the results of this pot experiment should be validated through field trials.

The Effectiveness of Arbuscular Mycorrhizal Fungi (AMF) on Gambier Seedlings’ (Uncaria gambir (Hunter) Roxb) Growth on Former Coal Mining Land

The availability of land limits gambier development; therefore, an alternative approach is to utilize land previously used for coal mining. This ex-coal mining land can be rehabilitated through the application of Arbuscular Mycorrhizal Fungi (AMF). This study aims to investigate the interaction between the type and dosage of AMF, as well as to identify the optimal type and dosage of AMF for the growth of Gambir seedlings. A Factorial Completely Randomized Design (CRD) was employed, incorporating two factors. The first factor consists of three types of AMF: Acaulospora sp, Glomus sp, and Gigaspora sp. The second factor pertains to the dosage of AMF, which includes 0 g/seedling, 5 g/seedling, 10 g/seedling, 15 g/seedling, and 20 g/seedling. The variables observed include soil chemical analysis, seedling height, number of leaves, and root crown ratio. The results indicate no significant interaction between the type and dosage of AMF on the growth of Gambir seedlings. However, the AMF type Glomus sp at a dosage of 20 g/seedling was found to be the most effective in promoting the growth of Gambir seedlings on ex-coal mining land.