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In the field of crop research, the study of roots involves many challenges, particularly the lack of effective methods for identifying crop roots. To deal with this problem, this study proposes a solution strategy: in applying strontium to crop leaves, the roots of different crops are distinguished. In this study, we applied strontium ions to the leaves of hydroponically grown wheat, and these strontium ions were partially absorbed by the leaves and transported to the roots. Therefore, the strontium concentration of roots was significantly increased through the foliar application of strontium. After mixing the treated wheat with the untreated wheat root, the greater the biomass of the wheat root applied with strontium ions, the higher the strontium concentration in the mixed root. Based on this phenomenon, we can establish the relationship between wheat root biomass and strontium concentration in mixed roots through linear fitting. Furthermore, we can also use the relationship between root biomass and root length to establish the correlation between strontium concentration in mixed roots and the root length of wheat with strontium ions. After measuring the strontium concentration of the mixed roots to be distinguished, the root biomass and root length of wheat applied with strontium ions can be calculated according to the equation obtained through linear fitting. The accuracy of this method was verified through a comparison with the actual value and the existing root staining method. The results show that the coefficient of determination (R2) of the root biomass estimation equation obtained through linear fitting reached 0.83, which is statistically significant (p < 0.01). The Pearson correlation coefficient with the measured value was more than 0.9, showing a very high correlation and significance. The root length estimation equation derived from the relationship between the root biomass, strontium concentration and root length was compared with the real root length value and the root length value obtained using the staining method. The Pearson correlation coefficient also exceeded 0.8 and reached a statistically significant level (p < 0.01). This study confirms that strontium ions can be absorbed and transported to roots through wheat leaves and successfully developed a new method for predicting the length of wheat roots, providing an effective new tool for wheat root research. [ABSTRACT FROM AUTHOR]

Soil microbial biomass (SMB) is a fundamental contributor to soil ecosystem services. Mycorrhizal fungi, a significant group of soil microbes, play essential roles in regulating carbon allocation and nutrient cycles. Acknowledging the profound importance of SMB and mycorrhizal symbiosis, our objective was to explore how mycorrhizal types modulate the global patterns of SMB across varied land use types (LUTs). Using data from 329 independent studies, we categorized vegetation species with defined mycorrhizal types into arbuscular mycorrhizal (AM) type (with 958 observations) or mixed AM and ectomycorrhizal (AM + ECM) type (with 481 observations). This categorization served as the foundation for our investigation into the impacts of various LUTs and environmental conditions (mean annual temperature, and mean annual precipitation, MAP) on global SMB patterns associated with specific mycorrhizal associations. The overall mean value of SMB was remarkably higher under AM + ECM type (92.23 ± 4.73 nmol/g) compared with that under AM type (49.45 ± 1.87 nmol/g) at a global scale. The primary factor contributing to this difference was the natural system. Additionally, the AM + ECM type (0.19 ± 0.01) exhibited a higher F:B ratio (Fungi‐to‐bacteria ratio) than the AM type (0.16 ± 0.001), attributed to the cumulative effects of different LUTs. Furthermore, SMB was markedly positively affected by aridity index under AM type and negatively influenced by temperature under AM + ECM type. Besides, MAP had a pronounced positive impact on SMB under AM type, while exhibiting a negative impact under AM + ECM type. Our study presented evidence affirming the essential role of mycorrhizal associations in shaping global patterns of SMB in response to environmental factors across varied LUTs. Key Points: Soil microbial biomass (SMB) was significantly higher under arbuscular mycorrhizal + ectomycorrhizal (AM + ECM) type compared to that under AM type, with this difference being most pronounced in the natural systemAM + ECM type had a higher F:B ratio than the AM type, attributed to the cumulative effects of different LUTsSMB exhibited a notable increase with aridity index under AM type, and a slight yet significant decrease with temperature under AM + ECM type [ABSTRACT FROM AUTHOR]

Fine roots are essential for terrestrial biogeochemical cycles. Mycorrhizal fungi's functions in regulating the uptake of carbon (C), nitrogen (N), and phosphorus (P) in plants are increasingly being recognized. However, the influence of mycorrhizae on Chinese plants' fine-root stoichiometry has not been considered. Herein, 772 plants with identified mycorrhizal types were divided into arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) types to investigate the differences in their fine-root stoichiometry and their driving factors. The results showed that the AM and ECM fine-root stoichiometries were significantly different (p < 0.001; p < 0.05). The AM plants' fine-root stoichiometry was mainly affected by the soil environment (8.76–90.12%), while ECM plants were more sensitive to climatic factors (23.51–52.41%). Further analysis showed that the mean annual temperature (MAT) was significantly correlated with AM plants' fine-root C and P and ECM plants' fine-root N and P. Mean annual precipitation (MAP) was significantly correlated with all AM plants' fine-root elements (p < 0.01) but was only negatively correlated with ECM fine-root P. It was concluded that the mycorrhizal type affects the response of the fine-root stoichiometry to climate and soil variations. Therefore, the mycorrhizal effect deserves attention when studying the relationship between plant nutrient uptake and environmental changes. [ABSTRACT FROM AUTHOR]

The use of arbuscular mycorrhizal fungi (AMF) is a vital strategy for enhancing the phytoremediation of heavy metals. However, the role of AMF under molybdenum (Mo) stress is elusive. A pot culture experiment was conducted to explore the effects of AMF (Claroideoglomus etunicatum and Rhizophagus intraradices) inoculation on the uptake and transport of Mo and the physiological growth of maize plants under different levels of Mo addition (0, 100, 1000, and 2000 mg/kg). AMF inoculation significantly increased the biomass of maize plants, and the mycorrhizal dependency reached 222% at the Mo addition level of 1000 mg/kg. Additionally, AMF inoculation could induce different growth allocation strategies in response to Mo stress. Inoculation significantly reduced Mo transport, and the active accumulation of Mo in the roots reached 80% after inoculation at the high Mo concentration of 2000 mg/kg. In addition to enhancing the net photosynthetic and pigment content, inoculation also increased the biomass by enhancing the uptake of nutrients, including P, K, Zn, and Cu, to resist Mo stress. In conclusion, C. etunicatum and R. intraradices were tolerant to the Mo stress and could alleviate the Mo-induced phytotoxicity by regulating the allocation of Mo in plants and improving photosynthetic leaf pigment contents and the uptake of nutrition. Compared with C. etunicatum, R. intraradices showed a stronger tolerance to Mo, which was manifested by a stronger inhibition of Mo transport and a higher uptake of nutrient elements. Accordingly, AMF show potential for the bioremediation of Mo-polluted soil. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhiza (AM) and ectomycorrhiza (ECM) are the two most common mycorrhizal types and are paid the most attention to, playing a vital common but differentiated function in terrestrial ecosystems. The leaf carbon isotope ratio (δ13C) is an important factor in understanding the relationship between plants and the environment. In this study, a new database was established on leaf δ13C between AM and ECM plants based on the published data set of leaf δ13C in China's C3 terrestrial plants, which involved 1163 observations. The results showed that the differences in leaf δ13C between AM and ECM plants related closely to life forms. Leaf δ13C of ECM plants was higher than that of AM plants in trees, which was mainly led by the group of evergreen trees. The responses of leaf δ13C to environmental changes were varied between AM and ECM plants. Among the four life forms, leaf δ13C of ECM plants decreased more rapidly than that of AM plants, with an increase of longitude, except for deciduous trees. In terms of the sensitivity of leaf δ13C to temperature changes, AM plants were higher than ECM plants in the other three life forms, although there was no significant difference in evergreen trees. For the response to water conditions, the leaf δ13C of ECM plants was more sensitive than that of AM plants in all life forms, except evergreen and deciduous trees. This study laid a foundation for further understanding the role of mycorrhiza in the relationship between plants and the environment. [ABSTRACT FROM AUTHOR]

BACKGROUND: Selenium (Se) is an essential micronutrient for humans and animals, but not for plants. Generally, cereals including wheat and rice are the main source of dietary Se for humans. Although arbuscular mycorrhizal fungi (AMF) are ubiquitous soil microbes and commonly develop symbionts with winter wheat (Triticum aestivum L.), the influence of AMF on accumulation and translocation of Se during developmental cycle of winter wheat is still unclear. RESULTS: Based on a pot trial, the present results indicated that the effects of AMF on grain Se concentration in winter wheat depend on the Se species spiked in the soil and that Rhizophagus intraradices (Ri) significantly enhanced grain Se concentration under selenite treatment. Moreover, inoculation of AMF significantly increased grain Se content under selenite and selenate treatments. The enhanced grain Se content of mycorrhizal wheat could be attributed to (i) apparently increased root growth of mycorrhizal wheat at jointing could absorb more Se for translocating to aerial tissues and consequently result in significantly higher stalk Se content and (ii) enhancing Se translocation from vegetative tissues to grains. The present study showed that AMF significantly (P < 0.05) increased pre‐anthesis Se uptake under selenate treatment and post‐anthesis Se uptake under selenite treatment. CONCLUSION: The present study indicated the feasibility of inoculation of AMF for increasing grain Se concentration under selenite treatment and enhancing the efficiency of biofortification of Se under selenate treatments. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Nitrogen (N) deposition is known to significantly affect plant growth. Mycorrhizas play an important role in plant productivity, and plants of different mycorrhizal types respond differently to global change, which will inevitably affect plant response to N deposition. However, little is known about the differences of different mycorrhizas in biomass allocation of host plants in response to N addition. Here, a meta-analysis of data from N addition experiments was carried out to analyze the response of biomass in arbuscular mycorrhiza (AM) and ectomycorrhiza (ECM) plants to N addition. The results showed that biomass of leaf, stem, fine root (FR), and litter between AM and ECM plants responded differently to N addition (p < 0.05). Among them, biomass of leaf and stem in ECM plants (leaf: 46.89%; stem: 45.59%) was more sensitive (positively) to N addition than AM plants (leaf: 27.84%; stem: 10.30%) (p < 0.05). N addition suppressed biomass of FR in AM plants (−11.22%) but promoted that in ECM plants (13.77%). The effects on biomass also varied with different functional groups between AM and ECM plants. However, the N responses were influenced by other resources. When other treatments were added, biomass was less varied in AM plants compared to ECM plants. In addition, the N response of WB (whole biomass) and root biomass were positively correlated with annual temperature in ECM plants, but that in AM plants did not. The effects on shoot biomass in AM and ECM plants to N addition both decreased with annual temperature. The N response of root biomass increased with annual precipitation. It can be seen that different mycorrhizal types regulate the response of different plant organ biomass to N addition, which is significant for predicting ecosystem responses and feedback to environmental change. [ABSTRACT FROM AUTHOR]

Leaf nitrogen (N) and phosphorus (P) are the most important functional traits in plants which affect biogeochemical cycles. As the most widely observed plant–fungus mutualistic symbiosis, mycorrhiza plays a vital role in regulating plant growth. There are different types of mycorrhiza with various ecological functions in nature. Drought, as a frequent environmental stress, has been paid more and more attention due to its influence on plant growth. Numerous studies have confirmed that drought affects the concentration of N and P in plants, but few studies involve different mycorrhizal types of plants. In this study, the differences of N and P between arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) plants under different drought patterns, drought duration and cultivation conditions were explored based on a dataset by a meta-analysis. Drought stress (DS) showed negative effects on AM plant N (−7.15%) and AM plant P (−13.87%), and a positive effect on AM plant N:P ratio (+8.01%). Drought significantly increased N and the N:P ratio of ECM plants by 1.58% and 3.58%, respectively, and decreased P of ECM plants by −2.00%. Short-term drought (<30 d) reduces more N and P than long-term drought (<30 d) in AM plant species. The duration of drought did not change the N concentration of ECM plant N, while short-term drought reduced ECM plant P. The effects of N and P on DS also varied with different planting conditions and functional groups between AM and ECM plants. Therefore, mycorrhizal effects and stoichiometry of N and P play a key role in plant response to drought. So mycorrhizal effects should be considered when studying plant responses to drought stress. [ABSTRACT FROM AUTHOR]

(1) Background: Understanding the diversity of communities of arbuscular mycorrhizal fungi (AMF) is the basis for understanding the ecological functions of AMF. (2) Methods: The community diversity and distribution of AMF at different elevations in tropical montane rainforests of Mt. Jianfenfling and Mt. Diaoluo were explored using high-throughput sequencing technology. (3) Results: A total of 283 AMF operational taxonomic units (OTUs) were identified from roots and the number of unique OTUs was 173, accounting for 61.13% of the total number discovered in these tropical montane rainforests. At different altitudes, high turnovers of AMF were observed, with the maximum proportion of unique OTUs between two altitudes being 45.16%, recorded between a.s.l. 250 m and 900 m on Mt. Diaoluo. The highest Sobs, Shannon and Pielou diversity indices appeared at 650 m on Mt. Diaoluo. For the two mountains, the soil properties of C, N and C/N have significant impacts on the genera Scutellospora, Paraglomus and unclassified in Archaeosporaceae, while the genera Glomus, Diversispora and Acaulospora are significantly affected by soil P and pH. It can be considered that altitude probably determines the presence of AMF communities by affecting edaphic properties. (4) Conclusions: There are abundant AMF associated with roots in the tropical montane rainforests of China. Furthermore, a high turnover of OTUs was found to exist between the mountains and at different altitudes, revealing diverse AMF community structures in tropical montane rainforests. [ABSTRACT FROM AUTHOR]

(1) Background: environmental gradient strongly affects microbial biodiversity, but which factors drive the diversity of arbuscular mycorrhizal fungi (AMF) associated with roots at relatively large spatial scales requires further research; (2) Methods: an experiment on large spatial scales of Mt. Taibai was conducted to explore the biodiversity and drivers of AMF-associated with roots using high-throughput sequencing; (3) Results: a total of 287 operational taxonomic units (OTUs) belong to 62 species representing 4 identified and 1 unclassified order were identified along different altitudinal gradients. With increasing altitude, AMF colonization could be simulated by a quadratic function trend, and altitude has a significant impact on colonization. AMF alpha diversity, including the Sobs and Shannon indexes, tended to be quadratic function trends with increasing altitude. The highest diversity indices occurred at mid-altitudes, and altitude had a significant effect on them. AMF communities have different affinities with soil and root nutrient, and Glomus is most affected by soil and root nutrient factors through the analysis of the heatmap. Glomus are the most dominant, with an occurrence frequency of 91.67% and a relative abundance of 61.29% and 53.58% at the level of species and OTU, respectively. Furthermore, AMF diversity were mostly associated with soil and root nutrients; (4) Conclusions: in general, AMF molecular diversity is abundant in Mt. Taibai, and altitude and nutrient properties of soil and root are the main influencing factors on AMF diversity and distribution. [ABSTRACT FROM AUTHOR]

Mycorrhizal types are a predictive framework for nutrient cycling within and across ecosystems, and their types represent different nutrient-acquisition strategies for plants. Carbon (C), nitrogen (N) and phosphorus (P) stoichiometric ratios are essential for understanding biogeochemical processes. The purpose of this study was to reflect the balance in the process of plant resource acquisition by exploring the C, N and P stoichiometric ratios (C/N, N/P, and C/P) in shrub organs in different mycorrhizal types. In this study, the C, N, and P stoichiometric ratios in leaves, stems and roots were analyzed in the types of arbuscular mycorrhizal (AM), ectomycorrhizal (ECM) and AM + ECM of shrubs in Northern China. The results showed that C/N in the stems and roots of AM plants (95.75 and 81.42) was significantly lower than in AM + ECM plants (109.89 and 102.37) and ECM plants (107.67 and 96.93), while both N/P and C/P in the leaves, stems and roots of AM shrubs (38.67, 36.17, 40.69; 1028.14, 2989.13, and 2659.18) were significantly higher than in ECM shrubs (30.52, 22.31, 20.47; 796.51, 2208.28, and 1714.95). Moreover, different elements among the same plant organs were closely correlated, and the same pattern was found among the same element ratios among different plant organs. This suggests that mycorrhizal type can influence C, N and P ratios among different organs. [ABSTRACT FROM AUTHOR]

The mycorrhizal traits of plants have been widely reported based on different scales or plant functional groups. To better utilize mycorrhizae to improve the cultivation yield and active ingredient accumulation of medicinal plants, a database of medicinal plant mycorrhizal characteristics is needed. A database on mycorrhizal traits including mycorrhizal type or status of Chinese medicinal plant species was assembled. In this study, the mycorrhizal type or status of a total of 3,230 medicinal plants was presented. Among them, the mycorrhizal traits of 1,321 species were ascertained. These medicinal plants had three mycorrhizal statuses, both single mycorrhiza (SM) and multi-mycorrhiza (MM) contained four mycorrhizal types. The majority of medicinal plants were obligatorily symbiotic with mycorrhizal fungi with 926 (70.10%) species. The most widespread mycorrhizal type is AM, which is associated with 842 medicinal plant species (90.93% of mycorrhiza has an obligatorily symbiotic relationship with Chinese medicinal plants). Another broadly studied mycorrhizal type is ECM, which is associated with 15 medicinal plant species. This study is the first exclusive database on mycorrhizal traits of medicinal plants, which provides both mycorrhizal type and status. This database provides valuable resources for identifying the mycorrhizal information of medicinal plants and enriching the theory of mycorrhizal traits, which will greatly benefit the production or management of medicinal plants. [ABSTRACT FROM AUTHOR]

Mycorrhizal strategies include mycorrhizal statuses and mycorrhizal types, which are important reflections of the functional characteristics of ecosystems. The stoichiometry of carbon, nitrogen, and phosphorus in plant organs is an important part of ecosystem functions, which has an important impact on the nutrient cycle of the ecosystem. The concentration of carbon, nitrogen, and phosphorus played a crucial role in ecosystem functioning and dynamics. The purpose of this study is to provide theoretical basis and data support for improving the properties of global terrestrial ecosystems by exploring the impact of mycorrhizal strategies on the stoichiometry of C, N, and P in different shrub organs. In this study, stoichiometric patterns of carbon (C), nitrogen (N) and phosphorus (P) in different shrub organs under different mycorrhizal status or types were analyzed at 725 samples across Northern China. Results showed that in different mycorrhizal status, the highest carbon concentration in shrub organs appeared in the facultatively mycorrhizal (FM) mycorrhizal status, and the highest nitrogen concentration appeared in the Non-mycorrhizal (NM) mycorrhizal status. Under different mycorrhizal types, the nitrogen concentration in the shrub organs under the arbuscular mycorrhiza (AM) mycorrhizal type was the highest, and the phosphorus concentration under the ecto-mycorrhiza (ECM) mycorrhizal type was the highest. In the OM or FM mycorrhizal status, the concentrations of C, N, and P in the stems and leaves increase with the increase of the concentrations of C, N, and P in the roots. In the NM mycorrhizal status, the N concentration in the stems and leaves increases with the increase of the N concentration in the roots. Under AM, AM+ECM, and ECM mycorrhizal type, the concentrations of C, N, and P are closely related in roots, stems and leaves. The content of plant nutrients in different organs is closely related. It turned out that mycorrhizal statuses or types are able to alter the allocation of C, N, and P in different organs, and the relationships of C, N, and P among different organs are able to present different trend with the varying of mycorrhizal statuses or types. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi (AMFs) play a vital role in ecosystems, especially in ecosystem variability, diversity, and function. Understanding the AMF diversity, distribution, and their driver at different altitudinal gradients is a benefit for understanding the ecological function of AMF in mountain ecosystems. In this study, we explored the AMF molecular diversity and their distribution from 660 to 3,500 m a.s.l. in Mount Taibai of Qinling Mountains based on high-throughput sequencing technology. A total of 702 operational taxonomic units (OTUs) in 103 species of AMF are isolated from soil samples, which belong to 18 identified and 1 unidentified genus in 10 families. The fungi in the genus of Glomus is the most dominant, with the occurrence frequency of 100% and the relative abundance of 42.268% and 33.048% on the species and OTU level, respectively. The AMF colonization in root could be simulated by a cubic function with the change of altitudes with the peak and trough at a.s.l. 1,170 and 2,850 m, respectively. Further, AMF diversity indices including Sob, Shannon diversity, and Pielou evenness also showed the same cubic function change trends with increasing altitude at OTU and species levels. However, the average values of diversity indices at OTU level are always higher than these at the species level. Based on the OTU level, the highest and lowest values of Shannon and Pielou indices are observed at the altitudes of 1,400 and 2,800 m, respectively. The pattern of AMF community distribution in Mt. Taibai is driven by altitude with the characteristics of more abundance in the medium- to low-altitude than high-altitude areas. In general, abundant AMF molecular diversity and species exit in different elevations of Mt. Taibai, which indicate gradient changes with elevations. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal (AM) fungi (AMF) can not only improve soil and plant health, but also alter the accumulation of contaminants in plants. Here, the effects of AMF on the contents of organic contaminants and the underlying mechanisms are summarized. Data show that AMF widely occur in sites contaminated with organic chemicals. In most cases, AMF improve plant tolerance to organic contaminants and enhance crop growth, leading to increased biomass of the crops. Overall, AMF decrease organic contaminant residues in crop shoots, but often cause increased accumulation of contaminants, especially persistent organic pollutants (POPs), in crop roots. The benefits and mechanisms behind AMF's role in ameliorating organic contaminant residues in crops can be summarized as follows: (1) increased biomass via improved mineral nutrition and water availability; (2) alleviation of oxidative stress induced by contaminants; (3) enhanced activities of contaminant degradation-related enzymes; (4) accumulation and sequestration of contaminants by AMF structures; (5) glomalin-related soil protein (GRSP)-triggered changes in bioavailability of contaminants; (6) stimulation of contaminant-degrading microorganisms in soil; (7) improved soil structure; and (8) reduced pesticide application via enhanced crop resistance to pathogens and improved competition with weeds. Finally, future challenges and perspectives regarding AMF's contribution to crop safety are proposed. [ABSTRACT FROM AUTHOR]

Global climate change is one of the most pressing conservation challenges; in particular, changes in precipitation regimes have already substantially influenced terrestrial ecosystems. However, the mechanisms influencing precipitation changes on individual plants and the plant communities in desert grasslands have yet to be fully elucidated. We therefore examine the influence of increased precipitation on plant community compositions in the Gurbantunggut Desert, Xinjiang, northwestern China, from 2005 to 2009. We found that growth of all plant species and the community productivities increased markedly with enhanced water input. Cover of ephemeral synusia also significantly increased due to increased precipitation, implying that the role of the ephemeral community for stabilization of sand dunes was strengthened by increased precipitation. The response of plant community compositions to increased precipitation was primarily reflected as changes in plant density, while increased precipitation did not affect plant species richness and the diversity index. Dominant species drove the response of plant density to increasing precipitation during the five‐year study period. However, the relative responses of rare species were stronger than those of the dominant species, thereby potentially driving species turnover with long‐term increased precipitation. This finding improved our understanding of how increased precipitation drives the changes in plant community composition in desert grasslands and will help to better predict changes in the community composition of ephemerals under future global climate change scenarios. [ABSTRACT FROM AUTHOR]

Elevational patterns of plant and animal diversity have been studied for centuries; however, the effects of land elevation on arbuscular mycorrhizal (AM) fungal diversity remains unclear. We examined AM fungal diversity and distribution along 19 elevation belts in Mount Taibai of the Qinling Mountains, with the aim to assess the altitudinal diversity patterns. In total, 63 AM fungal taxa belonging to 12 genera were discovered. Mycorrhizal colonization rates on roots; AM fungal spore density; and fungal species richness, evenness, and diversity had different patterns in terms of the changes of elevation. Root colonization followed a cubical parabolic pattern, with a peak and a foot at an elevation of about 2000 and 3000 m above sea level, respectively. Species richness decreased monotonically from the lowest to the highest elevations. Spore density and α-diversity exhibited a unimodal pattern and peaked at an elevation of 2107 and 1350 m, respectively. Species evenness increased monotonically at an elevation of between 1050 and 2250 m. β-Diversity also presented a basically incremental pattern along altitudinal gradients. Our findings suggest that elevation changes were the main factor governing the patterns of AM fungal diversity. [ABSTRACT FROM AUTHOR]

The effect of three arbuscular mycorrhizal (AM) fungi on phosphorus (P) nutrient activation and acquisition by maize from spatially heterogeneous sand was investigated using dual-mesh packages enriched with different P concentrations and compared with non-mycorrhizal cotrols. As would be expected the AM fungi significantly enhanced leaf photosynthetic rate and the biomass and P concentrations in shoots and roots. All three fungi (Glomus intraradices, Glomus mosseae and Glomus etunicatum) displayed the capacity to dissolve inorganic P and promoted P nutrient availability in the packages (P patches). G. etunicatum showed the largest effect comparing with Glomus intraradices and Glomus mosseae, particularly in packages with high concentrations of P. Possible mechanisms involved include the acidification of the P patches by the AM fungi, promotion of the dissolution of the P, and more marked effects of the three fungal isolates with increasing enrichment of P in the patches. Inoculation with G. etunicatum resulted in greater acidification compared to the other two fungi. We conclude that AM fungi can promote P availability by acidifying the soil and consequently exploiting the P in nutrient patches and by facilitating the growth and development of the host plants. [ABSTRACT FROM AUTHOR]

This article presents a comprehensive subpixel water mapping algorithm to automatically produce routinely open water fraction maps in the Tibetan Plateau (TP) with the Moderate Resolution Imaging Spectroradiometer (MODIS). A multi-index threshold endmember extraction method was applied to select the endmembers from MODIS images. To incorporate endmember variability, an endmember selection strategy, called the combined use of typical and neighboring endmembers, was adopted in multiple endmember spectral mixture analysis (MESMA), which can assure a robust subpixel water fractions estimation. The accuracy of the algorithm was assessed at both the local scale and regional scale. At the local scale, a comparison using the eight pairs of MODIS/Landsat 8 Operational Land Imager (OLI) water maps demonstrated that subpixels water fractions were well retrieved with a root mean square error (RMSE) of 7.86% and determination coefficient (R2) of 0.98. At the regional scale, the MODIS water fraction map in October 2014 matches well with the TP lake data set and the Global Lake and Wetland Database (GLWD) in both latitudinal and longitudinal distribution. The lake area estimation is more consistent with the reference TP lake data set (difference of −3.15%) than the MODIS Land Water Mask (MOD44W) (difference of −6.39%). [ABSTRACT FROM AUTHOR]

• Plant and AMF community are correlated in Central Asia, support Habitat Hypothesis. • Stability of plant and AMF community are positively correlated and related to SM. • Plant-AMF symbioses stability sharply decrease, when SM drop down to the threshold. Terrestrial ecosystems are composed of above- and belowground community, which have been researched separately for many years even though the two subsystems clearly interact with each other. And it is still less understood how the above- and belowground ecosystems co-response to the changing precipitation in this changing world. To understand the interdependence and co-responses of plant-arbuscular mycorrhizal (AM) fungi symbioses to this facet of climate change, we examined the plant and AM fungal diversity and abundance along both, a transect from east to west of the desert which exhibits an annual precipitation gradient and a topographical transect of a typical sand dune which exhibits a gradient of soil moisture but equal precipitation, in a temperate desert in Central Asia. The results showed that community structure and biomass of plants and AM fungi along both transects were positively correlated and related to either precipitation or soil moisture, strongly support the Habitat Hypothesis. We found a soil moisture threshold between 0.64% and 0.86%, below which the variability of plant coverage, plant species richness, spore density and Shannon-wiener diversity index of both plant and AM fungal communities increased sharply yielding in an average threshold of 0.73% for the stability of plant-AMF symbioses. Our results highlight that increasing precipitation contributes to above- and belowground, and particularly to the overall AM-symbiotic stability in a desert ecosystem. This emphasizes the susceptibility and the importance plant-AMF symbioses for ecosystem stability to climate changes across different scales. [ABSTRACT FROM AUTHOR]

Leaf economic spectrum (LES) traits are considered to be the most important plant functional traits, greatly influencing element cycling and ecosystem processes. Mycorrhizal features are considered as part of the root economic spectrum constituting the whole plant economic spectrum, and thus probably linked to LES. Arbuscular mycorrhizas (AMs) are one of the most abundant symbiotic associations in nature, however, the relationship between the global LES traits and AMs remains unknown. Here, based on the global leaf traits database, 1037 plant species with ascertained mycorrhizal types are classified into arbuscular mycorrhizal (AM) and nonAM groups in order to explore the differences in LES traits between AM and nonAM plants. Results show the worldwide LES traits are greatly linked with mycorrhizal traits. For all plants, LES traits vary greatly, but AM plants display larger variations in the six LES traits than nonAM species. AM woody plants, especially trees, have shorter leaf lifespan (LL), lower leaf mass per area (LMA), and higher leaf nitrogen concentration (N mass), photosynthetic capacity (A mass) and dark respiration rate (R mass) than nonAM woody ones, but similar leaf phosphorus concentration (P mass). However, the LES traits of herbaceous plants showed no significant correlation with AMs. Compared to nonAM plants, more AM plants tend to adopt a "quick investment-return" strategy. In most cases, LES traits correlate significantly, but their interrelationships vary with mycorrhizal traits. In conclusion, AM plants possess highly varied LES traits and preference for a "quick" strategy, leading them to a high responsiveness to environmental challenges. • The relationship of the global foliar traits and arbuscular mycorrhizas was studied. • AM woody plants, especially trees, have different leaf traits with nonAM plants. • AM plants tend to adopt a "quick investment-return" strategy. • The worldwide leaf economic spectrum traits relate closely to mycorrhizal traits. [ABSTRACT FROM AUTHOR]

Mycorrhizas play a vital role in ecosystem function, diversity and productivity. However, mycorrhizas in tropical forests are considered to be a neglected area of research in contrast to the well-studied diversity patterns of macro organisms. To this end, soil samples from 0 to 30 cm in depth were collected from six or four elevations in a typical tropical forest of Mt. Jianfeng and Mt. Diaoluo in China. The arbuscular mycorrhizal fungal (AMF) diversity and community composition were explored among different elevations based on high-throughput barcoded sequencing on the Illumina MiSeq platform. Environmental variables of soil characteristics, and elevation on AMF community assembly were analyzed using canonical correspondence analysis. In total, 316 AMF operational taxonomic units (OTUs) were found to belong to four identified and one unclassified order, and Glomus was the most dominant genus in tropical forest. AMF communities or diversity did not clearly reflect local environmental conditions, the spatial distance between mountains and elevation. In total, 68% and 56% of taxa of AMF were observed on multiple elevations in Mt. Jianfeng and Mt. Diaoluo, respectively. Furthermore, 8.9% and 19% of OTUs were exhibited on all elevations in Mt. Jianfeng and Mt. Diaoluo, respectively. The AMF alpha diversity, richness and evenness were similar across the two surveyed tropical mountains. The influence of elevation showed no distinct role on the diversity of AMF taxa. Overall, AMF communities and diversity are abundant in tropical forests and with little influence of elevation in tropical forests of China. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal (AM) fungi (AMF) are widely known to form a symbiosis with most higher plants and enhance plant adaptation to a series of environmental stresses. Sweet sorghum (Sorghum bicolor (L.) Moench) is considered a promising alternative feedstock for bioalcohol production because of its sugar-rich stalk and high biomass. However, little is known of AMF benefit for biomass production and salt tolerance of sweet sorghum. Here, we investigated the effects of Acaulospora mellea ZZ on growth and salt tolerance in two sweet sorghum cultivars (Liaotian5 and Yajin2) under different NaCl addition levels (0, 0.5, 1, 2, and 3 g NaCl/kg soil). Results showed AMF colonized the two cultivars well under all NaCl addition levels. NaCl addition increased mycorrhizal colonization rates in Yajin2, but the effects on Liaotian5 ranged from stimulatory at 0.5 and 1 g/kg to insignificant at 2 g/kg, and even inhibitory at 3 g/kg. High NaCl addition levels produced negative effects on both AM and non-AM plants, leading to lower biomass production, poorer mineral nutrition (N, P, K), higher Na+ uptake, and lower soluble sugar content in leaves. Compared with non-AM plants, AM plants of both cultivars had improved plant biomass and mineral uptake, as well as higher K+/Na+ ratio, but only Yajin2 plants had a low shoot/root Na ratio. AM inoculation increased the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), and soluble sugar content in leaves. Overall, both cultivars benefited from mycorrhization, and Yajin2 with less salt tolerance showed higher mycorrhizal response. In conclusion, AMF could help to alleviate the negative effects caused by salinity, and thus showed potential in biomass production of sweet sorghum in saline soil. [ABSTRACT FROM AUTHOR]

Both metals and metal-based nanoparticles (NPs) can easily accumulate in soil, posing risks for plants and microbes. However, the interaction between NPs and toxic metals coexisting in soil is not yet well understood. Here, we studied the combined effects of ZnO NPs and Cd on sweet sorghum inoculated with or without the arbuscular mycorrhizal (AM) fungus Funneliformis caledonium . Plants were grown in soil amended with ZnO NPs (50, 250, and 500 mg/kg), alone or in combination with 5 mg/kg Cd. The two higher doses of ZnO NPs inhibited plant growth, leading to synergistic toxicity with Cd. However, at the lowest dose, ZnO NPs were non-phytotoxic, displaying antagonistic interactions with Cd on plant growth. When added with high doses of ZnO NPs, Cd significantly increased root Zn concentrations, but decreased shoot Zn concentrations at the low dose. Conversely, all doses of ZnO NPs significantly decreased shoot and root Cd concentrations. Furthermore, high doses of ZnO NPs generally inhibited soil enzyme activities, but Cd addition showed no significant or even stimulative effects, and mitigated the inhibitory effects of ZnO NPs. AM inoculation increased plant growth and P nutrition, and soil enzyme activities. When the low dose of ZnO NPs was added alone or in combination with Cd, AM inoculation decreased shoot Zn concentrations. Our results reveal complex interactions between ZnO NPs and Cd on plant growth and nutrition, plant Zn and Cd accumulation, and soil enzyme activities, while AM inoculation can help diminish the adverse effects induced by ZnO NPs and Cd. [ABSTRACT FROM AUTHOR]

ZnO nanoparticles (NPs) are considered an emerging contaminant when in high concentration, and their effects on crops and soil microorganisms pose new concerns and challenges. Arbuscular mycorrhizal (AM) fungi (AMF) form mutualistic symbioses with most vascular plants, and putatively contribute to reducing nanotoxicity in plants. Here, we studied the interactions between ZnO NPs and maize plants inoculated with or without AMF in ZnO NPs-spiked soil. ZnO NPs had no significant adverse effects at 400 mg/kg, but inhibited both maize growth and AM colonization at concentrations at and above 800 mg/kg. Sufficient addition of ZnO NPs decreased plant mineral nutrient acquisition, photosynthetic pigment concentrations, and root activity. Furthermore, ZnO NPs caused Zn concentrations in plants to increase in a dose-dependent pattern. As the ZnO NPs dose increased, we also found a positive correlation with soil diethylenetriaminepentaacetic acid (DTPA)-extractable Zn. However, AM inoculation significantly alleviated the negative effects induced by ZnO NPs: inoculated-plants experienced increased growth, nutrient uptake, photosynthetic pigment content, and SOD activity in leaves. Mycorrhizal plants also exhibited decreased ROS accumulation, Zn concentrations and bioconcentration factor (BCF), and lower soil DTPA-extractable Zn concentrations at high ZnO NPs doses. Our results demonstrate that, at high contamination levels, ZnO NPs cause toxicity to AM symbiosis, but AMF help alleviate ZnO NPs-induced phytotoxicity by decreasing Zn bioavailability and accumulation, Zn partitioning to shoots, and ROS production, and by increasing mineral nutrients and antioxidant capacity. AMF may play beneficial roles in alleviating the negative effects and environmental risks posed by ZnO NPs in agroecosystems. [ABSTRACT FROM AUTHOR]