Mycorrhizal Fungi Inoculation Research Articles

Metagenomics reveal arbuscular mycorrhizal fungi altering functional gene expression of rhizosphere microbial community to enhance Iris tectorum's resistance to Cr stress

Chromium (Cr) can disrupt a plant's normal physiological and metabolic functions and severely impact the microenvironment. However, limited studies have investigated the impact of arbuscular mycorrhizal fungi (AMF) inoculation on the rhizosphere microorganisms of Iris tectorum under Cr stress, and the mechanisms of how rhizosphere microorganisms interact with hosts and contaminants. In this study, we investigated the effects of AMF inoculation on the growth, absorption of nutrients and heavy metals, and functional genes of the rhizosphere microbial community of I. tectorum under Cr stress in a greenhouse pot experiment. The results showed that AMF significantly increased the biomass and nutrient levels of I. tectorum, while decreasing the content of Cr in soil. Furthermore, metagenome analysis demonstrated significant changes in the structure and composition of the rhizosphere microbial community after AMF formed a mycorrhizal symbiosis system with the I. tectorum. Specifically, the abundance of functional genes related to nutrient cycling (N, P) and heavy metal resistance (chrA and arsB), as well as the abundance of heavy metal transporter family (P-atPase, MIT, CDF, and ABC) in the rhizosphere microbial community were up-regulated and their expression. Additionally, the synergies between rhizosphere microbial communities were regulated, and the complexity and stability of the rhizosphere microbial ecological network were enhanced. This study provides evidence that AMF can regulate rhizosphere microbial communities to improve plant growth and heavy metal stress tolerance, and helps us to understand the potential mechanism of wetland plant remediation of Cr-contaminated soil under AMF symbiosis.

The Global Dilemma of Soil Legacy Phosphorus and Its Improvement Strategies under Recent Changes in Agro-Ecosystem Sustainability.

Phosphorus (P) is one of the six key elements in plant nutrition and effectively plays a vital role in all major metabolic activities. It is an essential nutrient for plants linked to human food production. Although abundantly present in both organic and inorganic forms in soil, more than 40% of cultivated soils are commonly deficient in P concentration. Then, the P inadequacy is a challenge to a sustainable farming system to improve the food production for an increasing population. It is expected that the whole world population will rise to 9 billion by 2050 and, therefore, it is necessary at the same time for agricultural strategies broadly to expand food production up to 80% to 90% by handling the global dilemma which has affected the environment by climatic changes. Furthermore, the phosphate rock annually produced about 5 million metric tons of phosphate fertilizers per year. About 9.5 Mt of phosphorus enters human food through crops and animals such as milk, egg, meat, and fish and is then utilized, and 3.5 Mt P is physically consumed by the human population. Various new techniques and current agricultural practices are said to be improving P-deficient environments, which might help meet the food requirements of an increasing population. However, 4.4% and 3.4% of the dry biomass of wheat and chickpea, respectively, were increased under intercropping practices, which was higher than that in the monocropping system. A wide range of studies showed that green manure crops, especially legumes, improve the soil-available P content of the soil. It is noted that inoculation of arbuscular mycorrhizal fungi could decrease the recommended phosphate fertilizer rate nearly 80%. Agricultural management techniques to improve soil legacy P use by crops include maintaining soil pH by liming, crop rotation, intercropping, planting cover crops, and the consumption of modern fertilizers, in addition to the use of more efficient crop varieties and inoculation with P-solubilizing microorganisms. Therefore, exploring the residual phosphorus in the soil is imperative to reduce the demand for industrial fertilizers while promoting long-term sustainability on a global scale.

Dual Inoculation of Rhizobium and Arbuscular Mycorrhizal Fungi Increases Soil-Total Nitrogen, Available Phosphorus, and Yield of Soybean in Vertisols

Soybean is a protein source food crop with high economic value. So far, national production has not been able to meet domestic demand resulting in continuing import of soybean. The use of rhizobium and arbuscular mycorrhizal fungi (AMF) as biological fertilizers could be an alternative to increase soybean production. The research aimed to investigate the effect of dual inoculation of rhizobium and arbuscular mycorrhizal fungi (AMF) on root nodules formation, AMF development, total-N and available P of Vertisols, and yield of soybean. This study was designed in a completely randomized design) with 4 treatments namely no inoculation (R0), rhizobium inoculation (R1), AMF inoculation (R2), and dual inoculation of rhizobium and AMF (R3), with four replications. The variables observed were the number of effective root nodules, AMF spore density, AMF colonization, soil total-N, available P, plant height, number of pods, and seed weight. The results showed that dual inoculation of rhizobium and AMF had a better effect on the number of effective root nodules, AMF spore density, AMF colonization, soil total- N, available P, plant height, number of pods, and seed weight compared to the single inoculation and un-inoculated treatments

Plant propagation Litsea garciae Vidal. with shoot cutting technique inoculated with arbuscular mycorrhizal fungi

Litsea garciae Vidal. (engkala, kalangkala) is a fruit-producing plant useful as a potential medicinal plant and food. The availability of seedlings is a must if their potential is to be developed. The study aimed to evaluate the formation and growth of roots and shoots of L. garciae shoot cuttings in response to growth regulators and arbuscular mycorrhizal fungi (AMF) inoculation. The study used a factorial experiment with a completely randomized design. The treatments tested were growth regulators (without and with rootone-F) and AMF inoculation (without and with AMF). The shoot cuttings were planted in a mixture of cocopeat and husk charcoal (2:1 v/v) and placed in a propagation box in a screen house for 12 weeks. The live percentage, the percentage of callus cuttings, the percentage of rooted cuttings, and the percentage of cuttings sprouting all shoot cuttings planted reached 100%. The interaction between rootone-F and AMF had no significant effect on initiating root and shoot growth. However, cuttings treated without or with rootone-F showed a positive response to AMF inoculation, particularly in primary root formation and secondary root count. The secondary roots’ length and wet and dry weights of the cuttings with rootone-F were significantly lower than those without rootone-F.

Growth and production of soybean on different inoculant sources of arbuscular mycorrhizal fungi and water saturation periods

Production expansion to suboptimal areas such as tidal land through the application of integrated land management technology is an effort to increase soybean production in Indonesia. The study aimed to evaluate the morphophysiological response of soybean treated with arbuscular mycorrhizal fungi (AMF) inoculation and duration of water saturation in tidal land. The study was conducted in April-October 2021 in the plastic house of the Research Field of the Faculty of Agriculture, Sriwijaya University, Palembang. The experiment used a randomized complete block design with two factors and 3 replications. The first factor was the source of AMF propagations (without inoculations, corn inoculants, soybean inoculants, sugarcane inoculants, and soybean-sugarcane inoculants). The second factor was the water saturation periods (0, 2, and 4 months since planting), so there are 15 treatments. The results showed that the interaction between the inoculant sources and the duration of water saturation had no significant effect on all parameters. The inoculant propagated in the media of sugarcane produced the highest effect as compared to other treatments. The water saturation for 2 or 4 months since planting gave soybean plants a better morphophysiological response than conventional cultivation.
 Keywords: AMF inoculants; morphophysiology; saturated soil culture; soybean

Some physio-biochemical traits of sunflower (<em>Helianthus annuus</em> L.) as affected by arbuscular mycorrhizal fungi inoculation under different irrigation treatments

Plant-arbuscular mycorrhizal (AM) fungi association is one of the oldest symbiotic relationships between organisms. This relationship may be more important under stress conditions such as drought and can help the host plant tolerate drought. This study was conducted in 2016 and 2017 at the Agricultural Research Farm of Razi University, Kermanshah, Iran to evaluate the effect of AM fungi (AMF) inoculation (with either Funneliformis mosseae or Rhizophagus intraradices) on some physio-biochemical traits of three sunflower cultivars under different soil irrigation treatments (severe water deficit stress, mild water deficit stress and well-watered). In both years, water deficit conditions significantly reduced leaf relative water content (RWC), chlorophyll concentrations (a, b and total) and shoot phosphorus concentration (SPC) while simultaneously increasing shoot proline levels and malondialdehyde (MDA) concentrations. AMF inoculation had positive effects on RWC, chlorophyll concentrations and SPC irrespective of sunflower cultivar and irrigation treatment. Shoot proline concentration and MDA reduced more in AM than non-AM plants. In most cases F. mosseae performed better than R. intraradices in terms of plant performance. Moreover, the improvements caused by AM fungi were more evident under water deficit than well-watered condition. It may be concluded that AM inoculation can alleviate the negative effects of water deficit stress on some important physio-biochemical traits of sunflower grown in the field, and can be considered as a practical and economical approach to improve crop performance in environments exposed to water limitations.

Early Effects of Mycorrhizal Fungal Inoculum and Fertilizer on Morphological and Physiological Variables of Nursery-Grown Nothofagus alessandrii Plants.

Nothofagus alessandrii (ruil) is an endangered relict species, endemic to the Mediterranean area of Chile, and one of the most threatened trees in the country. Its natural distribution area has been greatly reduced by the effect of human activities; the remaining fragments are mostly intervened and highly deteriorated as a habitat and refuge for the associated biodiversity. In order to produce healthy and resistant nursery plants for recovery and restoration of N. alessandrii forests, this study evaluates the early effects of mycorrhizal fungal inoculum (MFI) combined with fertilization on the cultivation of seedlings. The experiment was established under a completely randomized design with a factorial arrangement of the mycorrhizal factors (M0 = without mycorrhizal, M1 = Thelephora sp. and M2 = Hebeloma sp.) and fertilization (F1 = standard fertilization and F2 = intensive fertilization), with three replicates of each combination, for each type of plant (P1 = plants from one season and P2 = plants from two seasons). Each experimental unit corresponded to a group of 20 plants, with 720 plants in the test. The results indicate that application of fertilizer and MFI significantly affects some growth and photosynthesis parameters of ruil plants in one and two seasons. The morphological parameters obtained in the study show shoot height values ranging between 67 and 91 cm for P1 and between 96 and 111 cm for P2; while, for shoot diameter, values ranged between 7.91 and 8.24 mm for P1 and between 10.91 and 11.49 mm for P2. Although formation of fully developed mycorrhizal roots was not observed during the assay period, we conclude that inoculation of mycorrhizal fungi combined with fertilization could be an efficient strategy to produce a quality plant, in addition to maintaining a high photosynthetic capacity and, therefore, a higher percentage of survival in the field.

The Alien Invader, Rhus typhina L., Outperforms Its Native Competitor in the Scenario of Nitrogen Deposition and Arbuscular Mycorrhizal Fungi (AMF) Inoculation

Nitrogen deposition has been proven to facilitate the establishment of alien plants. Previous studies have certified that nitrogen deposition enhances the resource availability of habitats and promotes the growth of alien invaders. Arbuscular mycorrhizal fungi (AMF) symbiose with vascular plants and assist plants in nutrient acquisition. AMF colonization has been proven to be another driving factor of plant invasion. However, few studies have integrated nitrogen deposition and AMF inoculation into the exploration on invasion mechanism. Based on a trait approach, the present study subjected the alien invader, Rhus typhina L., and its co-occurring native species, Acer truncatum Bunge, to nitrogen deposition and AMF inoculation and compared the phenotypic variation in aboveground and belowground traits in an inter-specific competition experiment. Through the effects of different nitrogen deposition and AMF infection on the functional traits of R. typhina and A. truncatum, the effects of mycorrhizal symbiosis between R. typhina and A. truncatum on abiotic factors and interspecific relationships were analyzed. We found that inter-specific competition stimulated the colonization of AMF in R. typhina, however, decreased the colonization rate of AMF in A. truncatum. Correspondingly, inter-specific competition significantly reduced the plant growth of A. truncatum as the aboveground morphological traits including plant height and crown area, and belowground traits including root length, root surface area, root volume, number of root tips, number of root tip branches and number of root cross decreased for A. truncatum. Nitrogen deposition promoted the shoot growth of R. typhina rather than that of A. truncatum. AMF inoculation significantly affected the belowground traits of A. truncatum as the root length and root surface area significantly decreased after AMF inoculation in the mixture planting of the two species. The chlorophyll content of A. truncatum decreased without AMF inoculation, while nitrogen deposition enhanced the net photosynthetic rate of R. typhina. The alien invader R. typhina outperforms its native competitor in the simulated scenario of resource fluctuation and facilitates its establishment. We speculate that AMF colonization promotes the extension of R. typhina rhizosphere and, thus, accelerates the growth and invasion of R. typhina.

Effect of Arbuscular Mycorrhizal Fungi Inoculation on content and nutrient uptake of four-month-old Angsana (Pterocarpus indicus Willd.) plants in post-gold mining land in Bombana, Southeast Sulawesi

Mining activities are the main cause of nutrient-poor land and damage to soil physical properties. This condition also occurs in the post-Bombana gold mining area. thus negatively impacting plant growth response. Therefore, post-mining land remediation is carried out using environmentally friendly approaches such as Arbuscular Mycorrhizal Fungi and the use of adaptive local plant species such as Angsana (Pterocarpus indicus Willd.). This study aims to determine the levels and uptake of nutrients in the mycorrhizal P. indicus plant in post-gold mining field scale. Sampling was carried out in the laboratory of the Faculty of Forestry and Environmental Sciences, Halu Oleo University and observations of nutrient levels were carried out in the soil and plant laboratory of SEAMEO BIOTROP Bogor, this research was carried out for 3 months (May 2021). This research method used a Randomized Block Design (RAK) with 4 treatments, namely control, Glomus coronatum, G. claroideum and mixed AMF. The results showed that mixed AMF was effective in increasing N, Mn and Fe nutrient levels and G. claroideum increased P and K levels. Mixed AMF increased N, Mn and Fe nutrient levels and nutrient uptake in P. indicus plants four months old on the Bombana Gold Post Mining Land, Southeast Sulawesi.

Anatomical responses of leaf and stem of Catalpa bungei C.A.Mey. to nitrogen application and Rhizophagus intraradices inoculation

Plant morphology and anatomical structure are closely related to plant function, and their changes may affect physiological processes and may also be altered by nutrient availability or arbuscular mycorrhizal fungi (AMF) inoculation. To our knowledge, studies on the effect of AMF on plant anatomical characteristics under different nitrogen (N) levels are very scarce, especially in trees. Here, a pot experiment was carried out to evaluate the response of leaf and stem anatomy of Catalpa bungei using a two-factor completely randomized block design, including mycorrhizal inoculation (inoculation with Rhizophagus intraradices or not) and N application (low, medium, high). Regardless of the inoculation status, moderate N addition promoted leaf and stem development, while excessive N had a significant negative impact on the anatomical structure of seedlings. Compared with the non-inoculated treatments, AMF inoculation increased most of the leaf stomatal characteristic parameters and stem structural parameters of C. bungei seedlings, while significantly reduced leaf upper epidermis thickness (UET), lower epidermis thickness (LET), spongy tissue thickness (STT), and leaf thickness (LT) at low to medium N levels. In addition, the lenticel density (LD) at low N levels and the lenticel length (LL), width (LW), and area (SLA) at medium N levels in mycorrhizal seedlings were significantly higher than those in non-mycorrhizal seedlings. We concluded that AMF inoculation may significantly improve the water and gas exchange capacity of seedlings at least at low to medium N levels.

Effect of arbuscular mycorrhizal fungi inoculation on revegetation at Nukui Dam site, Japan

The establishment of the surviving arbuscular mycorrhizal (AM) fungi, Gigaspora margarita Becker & Hall, inoculated in revegetation at the Nukui Dam was studied. The population of AM fungi and AM colonization of three plant species Japanese hill cherry (Prunus jamasakura Sieb. ex Koidz, yamazakura-inoculated plant), eulalia (Miscanthus sinensis Anderss, susuki), and mugwort (Artemisia vulgaris Pampan, yomogi) were investigated to compare inoculated and non-inoculated treatments. The AM colonisation was enhanced in inoculated plots although natural or accidental AM fungi were involved in non-inoculated plots and successfully colonised. Coverage of soil surface was more than 80% and even reached nearly 100% in summer regardless of the soil amendment type.The number of spores and the percentage of colonisation of investigated plant roots, as well as the density of typical AM structures such as arbuscules, auxiliary cells, vesicles, and coiling hyphae by AM fungi in inoculated plots were higher than those in non-inoculated ones. Some spores were Gigaspora andGlomus-inoculated species and were relatively rich in inoculated plots of Yamazakura. There was a significant increase in the number of AM spores in inoculated treatments at a 5% confidence level (ANOVA, p<0.05) in Susuki and Yamazakura. Much more spores of Gigaspora sp.occurred in the rhizosphere soil of Yamazakura and Susuki plants in inoculated plots than in non-inoculated plots (2.33 and 3.73 times, respectively).The colonisation intensity and spore number in the rhizosphere were positively correlated. Therefore, inoculation at an early establishment should be important for the successive development of AM-plant symbiosis formation.

Friends to the rescue: using arbuscular mycorrhizal fungi to future-proof Australian agriculture

With a rising global population and the challenges of climate change, there is an increasing need to find solutions to maintain crop yields in an ecologically sustainable way. Although many studies have focussed on this issue, comparatively few are conducted in the southern hemisphere. This is worrisome because the geographical and geomorphological conditions within Australia differ greatly from the northern hemisphere. To ensure food security, approaches can rely on conventional agricultural methods as well as commercial arbuscular mycorrhizal (AM) fungal inoculants. Both approaches lack the capacity to be successful in the long term or could have unknown negative effects on the naturally occurring microbial communities. We advocate for a sustainable and holistic approach that combines the effective management of functionally diverse AM fungal communities with precision farming techniques while integrating landscape elements into agricultural fields. In addition, landowners and scientists should collaborate and communicate their work with industry and government to take forward the shift to a more-sustainable agriculture. In this way, we will be better able to secure our food production while restoring our soil ecosystems.

Inoculation of Arbuscular Mycorrhizal Fungi and Plant Growth Promoting Rhizobacteria Mediated Water Stress Tolerance in Quinoa Seeds by Modulating the Phenolics Compounds, Stress Markers, Osmolytes Accumulation and Antioxidant Defense

Inoculation of Arbuscular Mycorrhizal Fungi and Plant Growth Promoting Rhizobacteria Mediated Water Stress Tolerance in Quinoa Seeds by Modulating the Phenolics Compounds, Stress Markers, Osmolytes Accumulation and Antioxidant Defense

Effects of arbuscular mycorrhizal fungus inoculation on the growth and nitrogen metabolism of Catalpa bungei C.A.Mey. under different nitrogen levels.

Evidence suggests that arbuscular mycorrhizal fungi (AMF) may promote the growth of woody plants. However, the effects of AMF on nitrogen (N) metabolism in plants, especially trees, and its regulatory mechanism are rarely reported. Here, the effects of AMF inoculation on the growth and N nutrition status of Catalpa bungei under different N levels were reported. Three N levels (low, medium, high) and two mycorrhizal inoculation treatments (inoculation with Rhizophagus intraradices or not) were used with factorial design. The results showed that medium N could significantly improve the physiological metabolism and growth of C. bungei seedlings. However, when N was excessive, growth was significantly inhibited whether inoculated AMF or not. Compared with non-inoculated treatments, AMF inoculation could promote the absorption of N and P, improve photosynthesis under low to medium N levels, thus promoting the growth of seedlings. AMF changed the biomass allocation in seedlings by reducing the stem mass ratio and root/shoot ratio, and increasing the leaf mass ratio. At medium N levels, compared with non-inoculated treatment, AMF inoculation could significantly promote root growth by changing root hormone levels and improving root architecture and root activity. Under N addition, AMF inoculation could improve the absorption and assimilation of N by regulating the expression of key enzyme genes of N metabolism and nitrate transporter genes (NRT2.4, NRT2.5, NRT2.7) in roots, and enhancing the activities of the key enzyme of N metabolism. This study may provide a reference for the application of AMF in the cultivation and afforestation technology of C. bungei in Northwest China.

A response of biomass and nutrient allocation to the combined effects of soil nutrient, arbuscular mycorrhizal, and root-knot nematode in cherry tomato

IntroductionThe biomass and nutrient allocation strategies in plants are fundamental for predicting carbon storage and mineral and nutrient cycles in terrestrial ecosystems. However, our knowledge regarding the effects of multiple environmental factors on biomass and nutrient allocation remains limited.MethodsHere we manipulated soil composition (three levels), arbuscular mycorrhizal fungi inoculation (AMF, five levels), and root-knot nematode inoculation (RKN, two levels) using random block design to reveal the effects of these factors on biomass and nutrient allocation strategies of cherry tomato.Results and DiscussionOur results showed that biomass and nutrient allocation were affected by soil composition, AMF and RKN individually or interactively. The biomass and nutrient allocation in cherry tomato shows different adaptation strategies responded to the joint action of three factors. The reduction of soil nutrients increased belowground biomass allocation, and aboveground nitrogen and phosphorus concentration. AMF colonization increased aboveground biomass allocation and reproductive investment and promoted aboveground nitrogen and phosphorus inputs. Cherry tomato can mitigate the stress of RKN infection by investing more biomass and nutrients into belowground organs. Our study showed that plants can adjust their survival strategies by changing biomass and nutrient allocation to adapt to variation in soil abiotic and biotic factors. These findings contribute to our understanding of the adaptive processes of plant biomass and nutrient allocation strategies under multiple environmental factors.

Do commercial arbuscular mycorrhizal inoculants contain the species that they claim?

The use of arbuscular mycorrhizal (AM) fungal inoculants as a means to promote plant growth is gaining momentum worldwide. Although there is an increasing number of commercial products available for various applications, the quality of these remains uncertain. We determined the AM fungal species composition in eleven inoculants from four producers by using DNA metabarcoding and compared them to the AM fungal species declared on the product labels. Our DNA metabarcoding of the inoculants revealed a concerning discrepancy between the declared and detected AM fungal species compositions of the products. While nine products contained at least one declared species, two did not contain any matching species and all inoculants but one contained additional species not declared on the product label. These findings highlight the need for better guidelines and industry standards to ensure consumer protection in the AM fungal inoculum market. Additionally, we call for caution when using commercial AM fungal inoculants in scientific experiments without confirmatory information about their species composition.

The trade-in-trade: multifunctionalities, current market and challenges for arbuscular mycorrhizal fungal inoculants

The trade-in-trade: multifunctionalities, current market and challenges for arbuscular mycorrhizal fungal inoculants

Effect of Mycorrhizal Inoculation on Melon Plants under Deficit Irrigation Regimes

The shortage of good quantity and quality of water for irrigated agriculture is a major problem in arid and semiarid regions. To deal with this problem, deficit irrigation (DI) or arbuscular mycorrhizal fungi (AMF) inoculation have been proposed and adopted for many crops as a tool to save water, or to improve crop tolerance to drought stress. An experiment was conducted for two consecutive years to evaluate the effect of mycorrhizal inoculation on the physiological, morphological, yield, and quality characteristics of melon plants grown under deficit irrigation. Melon crop (Cucumis melo L. cv. Helios) was grown under field conditions adopting a split-plot design with four replications, where DI was the main factor and AMF inoculation was the secondary factor. DI treatments consisted of applying 60%, 80%, or 100% of crop evapotranspiration (ETc) on melon plants inoculated or not with a commercial biostimulant containing 50% of Rhizophagus irregularis, and 50% of Funneliformis mosseae. Moderate and severe deficit irrigation significantly reduced the relative water content, stomatal conductance, yield, nitrogen applied efficiency (NAE), and fruit firmness of the uninoculated plants, but significantly increased irrigation water use efficiency (IWUE) and the ascorbic acid content of the fruit. AMF had a positive effect on plant tolerance to moderate water stress, and on some fruit quality parameters (fruit length, firmness, and sugar content). The combined use of moderate deficit irrigation (80%) and soil inoculation with AMF on melon plants allows water savings without affecting fruit yield, and increases IWUE, NAE, and some fruit quality characteristics (firmness, SSC, and SSC/TA). Furthermore, the use of AMF plants could be worth it to reduce the yield loss and increase fruit quality, even with severe deficit irrigation (60%).

Coriander (Coriandrum sativum) Cultivation Combined with Arbuscular Mycorrhizal Fungi Inoculation and Steel Slag Application Influences Trace Elements-Polluted Soil Bacterial Functioning.

The cultivation of aromatic plants for the extraction of essential oils has been presented as an innovative and economically viable alternative for the remediation of areas polluted with trace elements (TE). Therefore, this study focuses on the contribution of the cultivation of coriander and the use of arbuscular mycorrhizal fungi (AMF) in combination with mineral amendments (steel slag) on the bacterial function of the rhizosphere, an aspect that is currently poorly understood and studied. The introduction of soil amendments, such as steel slag or mycorrhizal inoculum, had no significant effect on coriander growth. However, steel slag changed the structure of the bacterial community in the rhizosphere without affecting microbial function. In fact, Actinobacteria were significantly less abundant under slag-amended conditions, while the relative proportion of Gemmatimonadota increased. On the other hand, the planting of coriander affects the bacterial community structure and significantly increased the bacterial functional richness of the amended soil. Overall, these results show that planting coriander most affected the structure and functioning of bacterial communities in the TE-polluted soils and reversed the effects of mineral amendments on rhizosphere bacterial communities and their activities. This study highlights the potential of coriander, especially in combination with steel slag, for phytomanagement of TE-polluted soils, by improving soil quality and health.

Effects of Arbuscular Mycorrhizal Fungi on Leaf N: P: K Stoichiometry in Agroecosystem

Leaf nitrogen (N), phosphorus (P), and potassium (K) stoichiometry can reflect plant strategies of nutrient allocation, which play key roles in ensuring food security and maintaining nutrient balance in the agroecosystem. Arbuscular mycorrhizal fungi (AMF) inoculation is an effective and green management measure affecting nutrient uptake and utilization strategies, especially in the agroecosystem. However, the interplay between AMF and leaf nutrient stoichiometry that is important for sustainable agriculture remain underexplored. Therefore, the efficacy of AMF in improving leaf nutrients of host plants in agricultural ecosystems were tested with meta-analysis by 1932 pairs of observations in research publications from 1995 to 2022. Overall analysis showed that AMF inoculation increases leaf N, P, and K by 8.75%, 24.61%, and 13.54%, respectively. Moreover, leaf P: K increased by 11.74% by AMF inocula, but leaf N: P and N: K of host plants decreased by 15.38% and 5.52%, respectively. Furthermore, the AMF effect on leaf nutrient stoichiometry was significantly regulated by species, life cycle, and growth habits of host plants. The prominent efficacy of AMF was higher for leaf P in fruit (30.06%), perennial (30.19%), and woody plants (31.6%) than other groups. Moreover, AMF effects on leaf N: P: K stoichiometry of inoculated crops varied depending on the identity of AMF. The Glomeraceae (especially Rhizophagus genera) increased more leaf P content than other AMF families. Thus, the leaf nutrient of host plants significantly increased by AMF inocula, especially leaf P content in the agroecosystem. The effect of AMF on leaf N: P: K stoichiometry was related to plant species, plant life cycle, plant growth habits, and the identity of AMF. These findings highlight the response of AMF to the strategies of nutrient in host plants and provide a theoretical and applicable way for better crop yield and sustainable agriculture.