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Plant–fungal associations are frequently key drivers of plant invasion success. Foliar fungi can benefit their invasive hosts by enhancing growth promotion, disease resistance and environmental stress tolerance. However, the roles of foliar fungi may vary when a given invasive plant faces different stresses. In this study, we designed three independent experiments to evaluate the effects of a foliar fungus, Colletotrichum sp., on the growth performance of the invasive plant Ageratina adenophora under different soil conditions, as well as the responses of A. adenophora to the foliar fungal pathogen Diaporthe helianthi and to herbivory. We found that the soil type was the most influential factor for the growth of A. adenophora. The role of the foliar fungus Colletotrichum sp. varied in the different soil types but generally adversely affected leaf development in A. adenophora. Colletotrichum sp. may be a weak latent foliar pathogen that can enhance the pathogenicity of D. helianthi on leaves of A. adenophora and marginally reduce signs of herbivory by natural insects in the wild on A. adenophora seedlings. In general, the benefits of the foliar fungus Colletotrichum to the fitness of A. adenophora are not significant in the context of this experimental design. However, our data highlight the need to consider both aboveground and belowground biota in different soil habitats when evaluating the effects of foliar fungi.

Local pathogens can accumulate as asymptomatic endophytes, making it difficult to detect the impacts of invasive species as propagators of disease in the invaded range. We used the invasive plant Ageratina adenophora to assess such accumulation. We intensively collected foliar fungal endophytes and leaf spot pathogens of A. adenophora and co-occurring neighbours and performed an inoculation experiment to evaluate their pathogenicity and host range. Ageratina adenophora harboured diverse necrotrophic pathogens; its communities of endophytes and leaf spot pathogens were different in composition and shared only a small number of fungal species. In the pathogen communities of local plant hosts, 21% of the operational taxonomic units (OTUs), representing 50% of strains, also occurred as leaf spot pathogens and/or endophytes of A. adenophora. The local pathogen community was more similar to the endophytes than to the pathogens of A. adenophora. The inoculation experiment showed that local pathogens could infect A. adenophora leaves asymptomatically and that local plant hosts were susceptible to both A. adenophora endophytes and pathogens. Ageratina adenophora is a highly competent host for local pathogens, and its asymptomatic latent pathogens are fungi primarily shared with local neighbours. This poses challenges for understanding the long-term ecological consequences of plant invasion.

Anthocyanins composed the major pigments which conferred sensory and chemical values to red grapes and wines. Multiple factors involved in grape anthocyanin biosynthesis have been greatly covered to date. However, the endophytes which closely associate with plants, their possible roles in plant coloration are still under clear. Our present research firstly investigated the diversity distributions of culturable fungal endophytes (CFE) in different colored grapevine leaves which harvested from same vineyard and cultivar, and then proposed method to analyze the possible effects of these fungal endophytes on anthocyanin concentrations of grape cells. In totally 532 endophytic fungal isolates, 19 OTUs belong to 13 genera were isolated from five color different grapevine leaves. Obvious leaf color specificity of CFE communities were observed distribution in different colored grapevine leaves in this experiment. Assessing the influences of those isolated CFEs on anthocyanin concentrations of a teinturier grape pulp cells via dual culture system revealed that anthocyanin promotion fungal strains were more possibly isolated from red and purple colored grape leaves. And elite CFE strains such as DQ53 and DQ55, both belong to the fungal genus Epicoccum, which conferred significant promotion effects on grape cellular anthocyanin contents were selected out. And the transcriptions of anthocyanin biosynthesis association genes MYBA1, UFGT and F3′5′H in grape cells, were significantly influenced by these endophytic fungi, furtherly implicated the involvements of these genes in fungal endophytes-mediated grape cell anthocyanin promotion process. Additionally, endophytic fungi triggered anthocyanin promotion in grape cells seem independently to that of the light mediated anthocyanin synthesis pathway. This work demonstrated that beside other environmental factors, endophytes may also involve in grape anthocyanin metabolisms. And the study provided methods and clues to explore fungal endophytes in colored grape leaves which possibly applied in grape pigmentation processing.

The assembly of the root-associated microbiome provides mutual benefits for the host plant and bacteria in soils. It is interesting how invasive plants interact with the local soil microbial community and establish the soil bacterial community in the endosphere of these plants in the short term. In this study, we compared the bacterial community in the rhizosphere with that in the root endosphere of an invasive plant, Ageratina adenophora, using high-throughput sequencing. The results showed that the roots of A. adenophora selectively accumulated the genera Clostridium and Enterobacter, which are rarely distributed in the rhizosphere. This selective accumulation caused a switch in the bacterial composition at the phylum level from Bacteroidetes predominant in the rhizosphere to Proteobacteria dominant in the root endosphere of A. adenophora. Our data indicated the potential existence of a highly conserved signal recognition in which hosts, either invasive or native, enrich the endosphere bacteria, such as Clostridium, Enterobacter, etc., from the rhizosphere. Moreover, the accumulated bacteria were physiologically and genetically different at the strain level and displayed distinct roles in growth between invasive and native plants. The assembly of the bacterial community in the roots may be an advantageous strategy for A. adenophora in competition with native plants.

Pathogen accumulation after introduction is unavoidable for exotic plants over a long period of time. Therefore, it is important to understand whether plant invasion promotes novel pathogen emergence and increases the risk of pathogen movement among agricultural, horticultural, and wild native plants. In this study, we used multiple gene analysis to characterize the species composition of 104 isolates of

A total of 390 bacterial strains were obtained from rhizosphere soils of an invasive plant, Ageratina adenophora, and common native plants. These strains were evaluated for their plant growth-promoting (PGP) characteristics, including IAA and siderophore production and phosphate solubilization. These traits were dependent on bacterial phylogenetic position but independent of isolation sources. Twenty-four phylogenetically distinct strains were selected and evaluated for their effects on the plant performance of A. adenophora and the two native plants Fallopia multiflora and Arthraxon lanceolatus. All strains had a neutral influence on germination rate; however, the germination timing and aboveground and belowground growth of the three tested plants were significantly changed. Among all tested strains, 20.8% and 16.7% were beneficial for the aboveground and belowground growth of A. adenophora, but none were beneficial to the two native species. In contrast, no strain negatively affected the performance of A. adenophora, but more than half of the strains showed detrimental effects on the belowground growth of the two native species, and approximately half of them delayed the germination timing of F. multiflora. The phylogenetic position of strains distinctly affected plant performance. The bacteria accumulated in the rhizosphere soil of A. adenophora showed a host-specific growth-promotion of A. adenophora; however, such bacteria showed no more detrimental effects on the growth of the two native species than those inhabiting the native plants. Our data suggested that the increased bacterial number and altered species structure in the soils were able to provide a competitive advantage to A. adenophora after invasion.

To determine if Ageratina adenophora can accumulate diverse pathogens from surrounding native plants, we intensively sampled fungal communities, including endophytes, leaf spot pathogens and canopy air fungi, associated with Ag. adenophora as well as native plants in its invasive range. In total, we collected 4542 foliar fungal strains from 10 geographic sites, including 1340 from healthy leaves of Ag. adenophora, 2051 from leaf spots of Ag. adenophora and 1151 from leaf spots of 56 species of native plants and crops. Taxonomically, the common fungal genera included Colletotrichum, Diaporthe, Alternaria, Nemania, Xylaria, Neofusicoccum, Nigrospora, Epicoccum, Gibberella, Pestalotiopsis, Irpex, Schizophyllum and Clonostachys. We also isolated the cultivable fungi from 12 air samples collected from six areas in Yunnan Province, PR China. Among the total of 1255 air fungal isolates, the most common genera were Cladosporium, Trichoderma and Epicoccum. Among them, two new Remotididymella species, Remotididymella ageratinae from leaf spot of Ag. adenophora and Remotididymella anemophila from canopy air of Ag. adenophora were found. The two species showed both asexual and sexual reproductive structures. The conidia of R. ageratinae and R. anemophila are larger than those of R. anthropophila and R. destructiva. The size of ascospores of R. ageratinae and R. anemophila also differ from R. bauhiniae. Phylogenetic analysis of the combined ITS, LSU rRNA, rpb2 and tub2 sequences showed that R. ageratinae and R. anemophila each formed a distinct clade, separated from all species previously described in Remotididymella and confirmed them as new species belonging to Remotididymella. Full descriptions of R. ageratinae and R. anemophila are provided in this study.

The virulence evolution of multiple infections of parasites from the same species has been modelled widely in evolution theory, and the trajectories of evolution are relevant to parasite transmission mode, as well as to parasite and host population dynamics. However, experimental studies on this topic remain scarce, particularly regarding multiple infections by different parasite species. In this study, we employed the invasive plant Ageratina adenophora to verify the predictions made by the model. We observed that A. adenophora was a highly susceptible host to phylogenetically diverse foliar pathogens with mixed vertical and horizontal transmission within leaf spots. The pathogen community structure at the leaf spot level was determined by transmission mode. Over time, the pathogen community decreased in diversity; meanwhile, the vertically transmitted pathogens exhibited decreased virulence to the host A. adenophora, but the horizontally transmitted pathogens exhibited increased virulence to the host. Our results demonstrate that the predictions of classical models are still valid in a complex environment. Moreover, we propose that it is very important to determine whether the primary foliar pathogen of a given plant host is relevant to seedborne fungi, as this characteristic is an important factor in understanding pathogen-host interactions.

Airborne fungi and their ecological functions have been largely ignored in plant invasions. In this study, high-throughput sequencing technology was used to characterize the airborne fungi in the canopy air of the invasive weed Ageratina adenophora. Then, representative phytopathogenic strains were isolated from A. adenophora leaf spots and their virulence to A.adenophora as well as common native plants in the invaded range was tested. The fungal alpha diversities were not different between the sampling sites or between the high/low part of the canopy air, but fungal co-occurrences were less common in the high than in the low part of the canopy air. Interestingly, we found that the phytopathogenic Didymellaceae fungi co-occurred more frequently with themselves than with other fungi. Disease experiments indicated that all 5 Didymellaceae strains could infect A. adenophora as well as the 16 tested native plants and that there was large variation in the virulence and host range. Our data suggested that the diverse pathogens in the canopy air might be a disease infection source that weakens the competition of invasive weeds, a novel phenomenon that remains to be explored in other invasive plants.

Plant–fungal associations are frequently key drivers of plant invasion success. Foliar fungi can benefit their invasive hosts by enhancing growth promotion, disease resistance and environmental stress tolerance. However, the roles of foliar fungi may vary when a given invasive plant faces different stresses. In this study, we designed three independent experiments to evaluate the effects of a foliar fungus, Colletotrichum sp., on the growth performance of the invasive plant Ageratina adenophora under different soil conditions, as well as the responses of A. adenophora to the foliar fungal pathogen Diaporthe helianthi and to herbivory. We found that the soil type was the most influential factor for the growth of A. adenophora. The role of the foliar fungus Colletotrichum sp. varied in the different soil types but generally adversely affected leaf development in A. adenophora. Colletotrichum sp. may be a weak latent foliar pathogen that can enhance the pathogenicity of D. helianthi on leaves of A. adenophora and marginally reduce signs of herbivory by natural insects in the wild on A. adenophora seedlings. In general, the benefits of the foliar fungus Colletotrichum to the fitness of A. adenophora are not significant in the context of this experimental design. However, our data highlight the need to consider both aboveground and belowground biota in different soil habitats when evaluating the effects of foliar fungi., Soil type played the most important role in the growth of A. adenophora, and the role of the foliar fungus Colletotrichum sp. varied according to different habitats but in general adversely affected the growth of A. adenophora. The Colletotrichum sp. might be a weak latent pathogen and enhanced the pathogenicity of Diaporthe helianthi on leaves of A. adenophora. Colletotrichum sp. marginally reduced the feeding frequency of seedlings by natural enemies in the wild.

Some exotic plants become invasive because they partially release from soil-borne enemies and thus benefit from positive plant–soil feedbacks (PSFs) in the introduced range. However, reports that have focused only on PSFs may exaggerate the invader's competitiveness. Here, we conducted three experiments to characterize plant–soil–foliage feedbacks, including mature leaves (ML), leaf litter (LL), rhizosphere soil (RS) and leaves plus soil (LS), on the early growth stages of the invasive plant Ageratina adenophora. In general, the feedbacks from aboveground (ML, LL) adversely affected A. adenophora by delaying germination time, inhibiting germination rate and reducing seedling growth. The increased invasion history exacerbated the adverse effects of LL and LS feedbacks on seedling growth. These adverse effects were partially contributed by more abundant fungi (e.g. Didymella) or/and more virulent fungi (e.g. Fusarium) developed in the aboveground part of A. adenophora during the invasion. Interestingly, the aboveground adverse effects can be weakened by microbes from RSs. Our novel findings emphasize the important role of aboveground feedbacks in the evaluation of plant invasiveness, and their commonness and significance remain to be explored in other invasive systems.

Previously, specific interactions in morphology were observed between grape cells and endophytic fungal strains during a dual culture experiment. However, the biochemical impacts of these fungal endophytes on grape cells is also expected due to their potential application in grape quality management. After assessed multiple physiochemical traits to those grape cells which have co-cultured with different endophytic fungal strains in this study, and found the presence of fungal endophytes obviously triggered ROS stress responses in grape cells, and the biochemical status in grape cells were differentially modified by different fungal strains. In those tested endophytic fungal strains, RH37 (Epicoccum sp.), RH6 (Alternaria sp.), RH32 (Alternaria sp.) and RH34 (Trichothecium sp.) conferred greater metabolic impacts on grape cells. And soluble protein (SPr), total flavonoids (TF), total phenols (TPh) and malondialdehyde (MDA) on the other hand, were sensitive biochemical parameters which can be influenced in greater ranges than other detected parameters. Most interestedly, fungal endophytes shaped metabolites patterns in grape cells during the dual culture appeared fungal genus/species/strain-specificity. The work confirmed the significance of fungal endophytes in grape metabolic regulation and elucidated the possibility to purposely manage grape quality using tool of fungal endophytes.

Anthocyanins contribute greatly to the organoleptic and biochemical properties of grapes and wines. Although there are broadly documented factors involved in grape anthocyanin synthesis, the present work focused on fungal endophytes and their possible role in grape coloration. Our results showed that exposure to endophytic fungi within a dual culture system differentially affected total anthocyanin concentrations and PAL activities in grape cells. Grape cells dual cultured with fungal strains XH-2, R2-21 and B2-17 showed significant differences of their anthocyanin concentrations were subjected to further analysis of their anthocyanidin compositions. Compared to the no-fungus controls, grape cells exposed to fungal strains XH-2 and R2-21 exhibited quantitative promotion of their total anthocyanidin concentrations by 74% and 28%, respectively, whereas treatment with the fungus B2-17 reduced the anthocyanidin content by 19%. A total of 14 species of anthocyanidins were detected from the grape cells in these experiments. Most interestingly, exposure to any of these fungal strains differentially modified the compositional patterns of grape cellular anthocyanidins. The obvious upregulation of the transcription of VvMYB in grape cells treated with fungal strains XH-2 and R2-21 implies that the increased anthocyanin levels in these grape cells may be due to the activated transcriptional factors. In addition, the exposure of grape cells to extracts of these fungi initiated similar responses of anthocyanin contents and PAL activities to exposure to the living fungi and appeared obvious dosage effects. The influence of fungal endophytes on the coloration of grape berries was also examined in this study.

The virulence evolution of multiple infections of parasites from the same species has been modeled widely in evolution theory. However, experimental studies on this topic remain scarce, particularly regarding multiple infections by different parasite species. Here, we characterized the virulence and community dynamics of fungal pathogens on the invasive plant Ageratina adenophora to verify the predictions made by the model. We observed that A. adenophora was highly susceptible to diverse foliar pathogens with mixed vertical and horizontal transmission within leaf spots. The transmission mode mainly determined the pathogen community structure at the leaf spot level. Over time, the pathogen community within a leaf spot showed decreased Shannon diversity; moreover, the vertically transmitted pathogens exhibited decreased virulence to the host A. adenophora, but the horizontally transmitted pathogens exhibited increased virulence to the host. Our results demonstrate that the predictions of classical models for the virulence evolution of multiple infections are still valid in a complex realistic environment and highlight the impact of transmission mode on disease epidemics of foliar fungal pathogens. We also propose that seedborne fungi play an important role in structuring the foliar pathogen community from multiple infections within a leaf spot., Author summary A growing number of examples indicate that many plant diseases are caused by multiple taxa of microbes. Therefore, how virulence evolves in the context of multiple infections by different species with both vertical and horizontal transmission modes represents an important area of pathogen ecology and evolution, but there is a lack of experimental study. Here, we employ a naturally occurring host-parasite system, the invasive plant Ageratina adenophora and its foliar pathogens, to verify that theoretical predictions of classical models for virulence evolution are still valid in a complex realistic environment, i.e., the transmission mode determines the dynamics of the virulence and pathogen community under multiple infections. Moreover, we propose that seedborne fungi are important in structuring the foliar pathogen community consisting of multiple infections within a leaf spot. Our findings provide valuable information for understanding how multiple infections affect the key components, i.e., the virulence evolution and pathogen community dynamics, of host-pathogen interactions in the field.

In order to solve the problem of reasonable distribution of joint combination in the design process of manipulator. In the design of manipulator, the target trajectory of manipulator and the requirement of end attitude should be taken into account. By dividing the change of trajectory and terminal attitude according to the three components of X-Y-Z, the corresponding joint combination mode is given. The kinematics relation of the arm shape of the manipulator is established by using the D-H representation. The forward and inverse solutions are obtained by using the Robotics Toolbox in MATLAB, and the workspace is given. By checking whether there is a reasonable inverse solution to judge the appropriate joint combination mode, according to the change of the attitude at the end of the joint, it is increased according to the change of the posture at the end of the joint. Add the corresponding joint type to complete the target task. According to this method, the design idea of manipulator can be given clearly, which provides a reference for improving the rationality of manipulator joint combination.

Evidence accumulated in recent years supports the crucial role of remodeled cell walls (CWs) in enabling plants to adapt to environmental challenges. However, the metal tolerance and alleviation mechanisms involving the CWs by endophyte-plant interactions to toxic metals have not yet been elucidated. In the present study, these mechanisms are tested by exploring the maize (Zea mays) Cd tolerance by modifying its root CW structure via inoculation with a dark septate endophyte (DSE) fungus Exophiala pisciphila. Our present study demonstrates that the root CWs were the primary site for Cd accumulation, functioning as a sink for toxic Cd ions. Interestingly, E. pisciphila colonization significantly bioaugmented subcellular compartmentalization of maize roots and increased the Cd content of various CW subfractions through a significantly increased enzyme activity, e.g., pectin methylesterase, as well as an upregulated expression of genes involved in CW biosynthesis and changes in the contents of functional groups in pectin and hemicellulose 1 in response to Cd stress. Consequently, the enhanced Cd compartmentation in plant CWs by DSE lowers the entry of trace metals in the protoplast, thereby conferring the tolerant races of plants that can survive and thrive on metal-contaminated soils.

Some exotic plants become invasive because they partially release from soil-borne enemies and thus benefit from positive plant–soil feedbacks (PSFs) in the introduced range. However, reports that have focused only on PSFs may exaggerate the invader's competitiveness. Here, we conducted three experiments to characterize plant–soil–foliage feedbacks, including mature leaves (ML), leaf litter (LL), rhizosphere soil (RS) and leaves plus soil (LS), on the early growth stages of the invasive plant Ageratina adenophora . In general, the feedbacks from aboveground (ML, LL) adversely affected A. adenophora by delaying germination time, inhibiting germination rate and reducing seedling growth. The increased invasion history exacerbated the adverse effects of LL and LS feedbacks on seedling growth. These adverse effects were partially contributed by more abundant fungi (e.g. Didymella ) or/and more virulent fungi (e.g. Fusarium ) developed in the aboveground part of A. adenophora during the invasion. Interestingly, the aboveground adverse effects can be weakened by microbes from RSs. Our novel findings emphasize the important role of aboveground feedbacks in the evaluation of plant invasiveness, and their commonness and significance remain to be explored in other invasive systems.

Background Gastrodia elata is a widely distributed achlorophyllous orchid and is highly valued as both medicine and food. Gastrodia elata produces dust-like seeds and relies on mycorrhizal fungi for its germination and growth. In its life cycle, G. elata is considered to switch from a specific single-fungus relationship (Mycena) to another single-fungus relationship (Armillaria). However, no studies have investigated the changes in the plant-fungus relationship during the growth of G. elata in the wild. In this study, high-throughput sequencing was used to characterize the fungal community of tubers in different growth phases as well as the soils surrounding G. elata. Results The predominant fungi were Basidiomycota (60.44%) and Ascomycota (26.40%), which exhibited changes in abundance and diversity with the growth phases of G. elata. Diverse basidiomycetes in protocorms (phase P) were Hyphodontia, Sistotrema, Tricholoma, Mingxiaea, Russula, and Mycena, but the community changed from a large proportion of Resinicium bicolor (40%) in rice-like tubers (phase M) to an unidentified Agaricales operational taxonomic unit 1(OTU1,98.45%) in propagation vegetation tubers (phase B). The soil fungi primarily included Simocybe, Psathyrella, Conocybe, and Subulicystidium. Three Mycena OTUs obtained in this study were differentially distributed among the growth phases of G. elata, accounting for less than 1.0% of the total reads, and were phylogenetically close to Mycena epipterygia and M. alexandri. Conclusions Our data indicated that G. elata interacts with a broad range of fungi beyond the Mycena genus. These fungi changed with the growth phases of G. elata. In addition, these data suggested that the development of the fungal community during the growth of G. elata was more complex than previously assumed and that at least two different fungi could be involved in development before the arrival of Armillaria. Electronic supplementary material The online version of this article (10.1186/s12866-019-1501-z) contains supplementary material, which is available to authorized users.

To characterize the potential effects of an introduced fungus in a local ecosystem, an experiment was performed in an abandoned farmland, where a traditional Chinese medicinal plant, Gastrodia elata had been continuously cultivated using the introduced Armillaria M2 and it had not been grown for the last 6 years. In this case, a newly introduced Armillaria strain M1 was used to cultivate orchid G. elata again. Inoculating strain M1 showed an infection rate of 95.56% on G. elata, much higher than that of without, 22.2%. Molecular evidence showed that all Armillaria re-isolated from G. elata in the farmland were genetically identical to the introduced ones. It suggested that the introduced Armillaria completely blocked the infection of natural ones on G. elata. Such an effect could persist several years even after stopping cultivation of G. elata. A total of 53 strains of Armillaria were obtained from a variety of isolation sources. Analysis of their intergenic spacer (IGS) sequences revealed that diverse and novel species of Armillaria existed in local forest. They are valuable resources for cultivating G. elata in future. Regarding ecological risk, utilization of the introduced Armillaria is not recommendable for local farmers. Key words: Gastrodia elata, Armillaria, the introduced microbe, orchid, ecological risk.

Endophytes may gradually accumulate in the new geographic range of a non-native plant, just as pathogens do. To test this hypothesis, the dynamics of colonization and diversity of foliar fungal endophytes of non-native Ageratina adenophora were investigated. Previous reports showed that the time since the initial introduction (1930s) of A. adenophora into China varied among populations. Endophytes were sampled in three provinces of Southwest China in 21 sites that varied from 20 to 70 years since the introduction of A. adenophora from its native Central America. Endophyte isolation frequencies varied from 1.87 % to 60.23 % overall in a total of 4,032 leaf fragments. Based on ITS sequence variations, 463 fungal endophytes were distinguished as 112 operational taxonomic units (OTUs) belonging to the Sordariomycetes (77 OTUs, 373 isolates), Dothideomycetes (18 OTUs, 38 isolates), and Agaricomycetes (17 OTUs, 52 strains) classes. Colletotrichum (28.51 %), Nemania (14.90 %), Phomopsis (13.17 %), and Xylaria (4.97 %) were the most abundant genera. Both endophyte diversity and overall isolation frequency increased with time since introduction. The genetic differentiation of the fungus Colletotrichum gloeosporioides indicated that the dispersal of endophytes was likely affected by a combination of geographic factors and the invasion history of the host A. adenophora.

In this paper, some scholars’ idea of applying neural network technology in the design of hacker intrusion detection system model and making a hacker intrusion detection system model based on artificial neural network is adopted. This study selects KDDCup’99 for network intrusion detection data set to learn the characteristics of the intrusion accurately; completes the normalization of all characteristics to achieve rapid convergence of the artificial neural network; analyses the advantages and disadvantages of different neural network training functions; achieves a high accuracy rate for intrusion detection successfully.

Endophytes proved to exert multiple effects on host plants, including growth promotion, stress resistance. However, whether endophytes have a role in metabolites shaping of grape has not been fully understood. Eight endophytic fungal strains which originally isolated from grapevines were re-inoculated to field-grown grapevines in this study, and their effects on both leaves and berries of grapevines at maturity stage were assessed, with special focused on secondary metabolites and antioxidant activities. High-density inoculation of all these endophytic fungal strains modified the physio-chemical status of grapevine to different degrees. Fungal inoculations promoted the content of reducing sugar (RS), total flavonoids (TF), total phenols (TPh), trans-resveratrol (Res) and activities of phenylalanine ammonia-lyase (PAL), in both leaves and berries of grapevine. Inoculation of endophytic fungal strains, CXB-11 (Nigrospora sp.) and CXC-13 (Fusarium sp.) conferred greater promotion effects in grape metabolic re-shaping, compared to other used fungal strains. Additionally, inoculation of different strains of fungal endophytes led to establish different metabolites patterns of wine grape. The work implies the possibility of using endophytic fungi as fine-tuning regulator to shape the quality and character of wine grape.

This study evaluated the soil characteristics and nitrogen-fixing bacterial (NFB) communities inhabiting the rhizosphere of an invasive plant, Ageratina adenophora , in Southwest of China. In a large geographic range, heavily invaded (HI) soils generally had higher nutrient levels compared with lightly invaded (LI) and non-invaded (NI) ones. The NFB number and species diversity of HI soils were significantly greater than those of NI ones. A total of 416 NFB isolates were divided into 47 operational taxonomic units (OTUs). They were phylogenetically categorized into Proteobacteria (63.9%), Actinobacteria (32.2%), Firmicutes (1.9%) and Bacteroidetes (1.9%). At a lower taxonomic level, these isolates were grouped into 20 genera, among which, the dominant isolates were Arthrobacter , Mitsuaria , Burkholderia , Sinorhizobium , Pseudomonas and Rhizobium . The phylogenetical structures of NFB communities obtained from HI, LI and NI soils were slightly different, with their phylogenetic structure similarity indices ( θ YC ) being less than 0.8. However, the percentages of isolates represented by the shared species between any two communities were more than 80%, and in most cases, nearly 100%. There were 16 OTUs shared by these three communities (HI, NI and LI), representing 351 isolates (84.38% of total isolates). These facts indicated that numerically dominant species among HI, LI and NI soils were highly similar. In conclusion, A. adenophora invasion significantly increased the NFB number and diversity of soils, but did not change their phylogenetic structure of core community.

High-purity, homogeneous and ultra fine LaB 6 powders were prepared by combustion synthesis. The effects of reactant ratio and molding pressure on the phase and morphology of the combustion products were studied. The combustion products and leached products were analyzed by XRD, SEM and EDS. The results indicate that the combustion product consists of LaB 6 , MgO and a little Mg 3 B 2 O 6 . The combustion product becomes denser and harder when the molding pressure increases. The purity of LaB 6 is higher than 99.0%. The LaB 6 particle size is in range of 1.92–3.00 μm and the lattice constant of LaB 6 is a =0.414 8 nm.

The endophytic fungal composition of healthy leaves from an invasive plant (Eupatorium adenophorum) in China was investigated. Six morphologically different endophytes were found to inhabit the leaves. Based on a phylogenetic analysis of the internal transcribed spacer sequences (ITS), four morphotypes were close to Alternaria, Cladosporium, Pestalotiopsis, and Didymella, respectively, while two morphotypes were close to unidentified fungi. The frequency at which the endophytes occurred varied among leaves, branches, and individuals, with species diversity markedly increasing with increasing leaf age. Chemical conditions alone did not adequately explain the lower degree of endophytic fungal diversity in younger leaves. Competition between endophytes mediated through non-volatile and volatile metabolites were common and may be a major factor accounting for the heterogeneous distribution of endophytes in leaves of E. adenophorum.

Since endophytes can affect metabolism of host plants, they are expected to be used to improve crop quality, especially for crops with organoleptic sensitive products such as wine grape. However, details of metabolic interactions between endophytes and host plants were less understood. In this work, we used high pressure liquid chromatography (HPLC) to analyze the metabolites of fruit flesh cells of grape treated with dual culture of different endophytic fungal strains (EFS). We observed that the dual-culture with different fungal strains show different metabolites composition in grape cells. In response to different EFS, quantities of detected metabolites in grape cells varied from 6 to 17 in this assay, and 1 to 11 novel metabolites were introduced into metabolome of grape cells. Dual-culture with fungal strains CS2, RH16 and RH5 introduced the highest quantities (10 or 11) of novel metabolites in grape cells. More importantly, the modification of metabolic profiles in grape cells via fungal endophytes appeared to be fungal strain/genus-specificity. Overall, this work revealed that introduction of specific metabolites in host plants may be one consequence during the process of endophytes-host metabolic interactions, which raise the possibility to shape grape qualities and characteristics using tool of fungal endophytes.

The diversity of arbuscular mycorrhizal fungi (AMF) colonizing the roots and rhizosphere soils of Heteropogon contortus and Dodonaea viscose growing in a valley-type savanna, southwest China, were analyzed by the large subunit ribosomal RNA genes (LSU). A total of 547 AMF sequences were screened for establishment of four clone libraries. Phylogenetic analysis revealed that the sequences clustered in at least 8 discrete sequence groups, all belonging to the genus Glomus . Among the Glomus spp., Glo 1 (GlGr A) and Glo 7 (GlGr B) were the most common in all root and soil samples of the two xerophytes, accounting for 42% and 33% of all screened clones, respectively. The ∫-LIBSHUFF analysis revealed that the composition of AMF communities associated with the two xerophytic hosts varied greatly both in roots and their rhizosphere soils.

Pot culture experiments were established to determine the effects of colonization by arbuscular mycorrhizal fungi (AMF) (Glomus mosseae and G. sp) on maize (Zea mays L.) grown in Pb, Zn, and Cd complex contaminated soils. AMF and non-AMF inoculated maize were grown in sterilized substrates and subjected to different soil heavy metal (Pb, Zn, Cd) concentrations. The root and shoot biomasses of inoculated maize were significantly higher than those of non-inoculated maize. Pb, Zn, and Cd concentrations in roots were significantly higher than those in shoots in both the inoculated and non-inoculated maize, indicating the heavy metals mostly accumulated in the roots of maize. The translocation rates of Pb, Zn, and Cd from roots to shoots were not significantly difference between inoculated and non-inoculated maize. However, at high soil heavy metal concentrations, Pb, Zn, and Cd in the shoots and Pb in the roots of inoculated maize were significantly reduced by about 50% compared to the non-inoculated maize. These results indicated that AMF could promote maize growth and decrease the uptake of these heavy metals at higher soil concentrations, thus protecting their hosts from the toxicity of heavy metals in Pb, Zn, and Cd complex contaminated soils.

Iris bulleyana has long been used as a remedy for detoxication and detumescence. Hydrodistillation was used to extract the essential oil from its rhizomes, and 0.23% oil yield was obtained. Using gas chromatography-mass spectrometry (GC-MS) analysis, 31 chemicals including aristolone, cuparene, b-gurjunene, d-amorphene, a-muurolene, a-cadinol, camphor, g-elemene, and t-cadinol were identified. The essential oil exhibited antibacterial activity against Acetobacter calcoacetica, Bacillus subtillis, Clostridium sporogenes, Clostridium perfringens, Escherichia coli, Salmonella typhii, Staphylococcus aureus, and Yersinia enterocolitica. Its antifungal and antioxidant activities were also tested.

Bacterial communities in decaying sapwood and heartwood of Keteleeria evelyniana were demonstrated through constructing rRNA gene libraries. At 3% of sequence difference, 81 operational taxonomic units (OTUs) were identified from 91 partial 16S rRNA gene fragments. These clones belonged to Proteobacteria (63.7%), Actinobacteria (13.2%), Acidobacteria (8.8%), Firmicutes (3.3%), Chlamydiae (5.5%), Chloiroflexi (3.3%), Verrucomicrobia (1.1%) and Cyanobacteria (1.1%). The heartwood displayed higher species richness than the sapwood. No OTU overlapped between these two parts. Most α- and β-, and all δ-proteobacterial clones occurred in the heartwood, whereas γ-proteobacteria mainly occurred in the sapwood. Chlamydiae and Verrucomicrobia exclusively appeared in the heartwood, but Chloroflexi, Cyanobacteria, and Firmicutes, distributed in the sapwood. Clones belonging to Acidobacteria and Actinobacteria were also divided into distinct subgroups between in the sapwood and in the heartwood. Based on the present species definition, we estimated the wood-inhibiting bacteria of K. evelyniana achieved up 1056 species (ranging from 452 to 2647). Only small number of sequences (13/91) can be found the nearest neighbor previously cultured and named; thereby, the majority of wood-inhabiting bacteria still remains to be uncovered.

The ectomycorrhizal fungus Thelephora ganbajun is an endemic gourmet mushroom in Yunnan province, south-western China. However, despite its widespread consumer appeal, nutritional value and potential ecological role in natural forests, very little is known about its genetics, diversity and ecology. In this study, we investigated DNA sequence variation at the internal transcribed spacer (ITS) regions among 156 specimens collected from 23 sites of nine regions in Yunnan Province. Our analysis identified a total of 34 ITS haplotypes and these haplotypes were clustered into five distinct phylogenetic groups. The evolutionary divergences among these clades are similar to or greater than many known sister species pairs within the genus Thelephora and the closely related genus Tomentella. Among the 34 ITS haplotypes, 22 were represented by one specimen each and the remaining 12 were each shared by two or more specimens. The most common haplotype contained 68 specimens distributed in 21 of the 23 sites, a result consistent with gene flow among geographical populations. However, analysis of molecular variance (AMOVA) revealed low but significant genetic differentiation among local and regional populations. Interestingly, the Mantel test identified that the extent of genetic differentiation was not significantly correlated with geographical distance. Our study revealed significant genetic divergence within Th. ganbajun and limited but detectable gene flow among geographical populations of this endemic ectomycorrhizal gourmet mushroom.

To investigate the genetic diversity of Tricholoma matsutake, we studied ITS and IGS1 sequences and PCR polymorphism of a retrotransposon in 56 fruit bodies collected from 13 counties of 9 regions in Yunnan Province. We found one and three haplotypes based on ITS and IGS1 sequences, respectively. Moreover, there was no significant difference in PCR polymorphism of the retrotransposon among different populations. Compared with Jilin Province (China) and Japanese populations, although Yunnan was highly homogenous to Japanese populations, low genetic diversity of T. matsutake in Yunnan did not support the view that this species originated from Yunnan.

Bacillus nematocida B16 has been shown to use “Trojan horse” mechanism in pathogenesis that has characteristics of “social” behavior. The ComP-ComA system, a conserved quorum sensing system in the genus Bacillus, functions in many physiological processes including competence development, lipopeptide antibiotic surfactin production, degradative enzyme production and even some unknown functions. Here we investigated the requirement of ComP-ComA system in B. nematocida B16 for its pathogenicity against nematodes. The ΔcomP mutant displayed deficiencies in attracting and killing nematodes, due to the absence of attractive signal molecules and the decreased expressions of virulence factors, respectively. Contrarily, a complemented comP mutant at least partially resumed its pathogenicity. Our data from transcriptional analysis further confirmed that this signaling system directly or indirectly regulated the expressions of two major virulence proteases in the infection of B. nematocida B16. Bioinformatics analyses from comparative genomics also suggested that the potential target genes of transcription factor ComA were involved in the processes such as the synthesis of attractants, production of extracellular degradative enzymes and sortase, secondary metabolites biosynthesis, regulation of transcription factors, mobility, as well as transporters, most of which were different from a saprophytic relative B. subtilis 168. Therefore, our investigation firstly revealed that the participation and necessity of ComP-ComA signaling system in bacterial pathogenesis.

Mid-montane moist evergreen broadleaved forest (MMF) and top-montane dwarf mossy forest (DMF) are the two major natural forest types in subtropical mountainous area of Ailao Mountains, Northwest China. In this paper, a comparative study was made on the microbial composition, quantity, biochemical activity, metabolic activity, and their seasonal dynamics in the canopy- and understory humus of the two forest types. The composition, quantity, and metabolic activity of the microbes in the canopy humus of dominant tree species in MMF and DMF were also analyzed. In the canopy humus of the two forest types, the amounts of fungi and actinomycetes, microbial biomass C and N, and intensities of nitrogen fixation and cellulose decomposition were significantly higher than those in understory humus. Meanwhile, the amount of cellulose-decomposing microbes (ACDM), cellulose decomposition intensity, microbial biomass C and N, and metabolic activity in the canopy humus of MMF were significantly higher than those of DMF. The amounts of bacteria, fungi, and aerobic nitrogen-fixing bacteria (ANFB) and the metabolic activity in the canopy humus of MMF and DMF were significantly higher in wet season than in dry season, while a contradictory trend was observed on the amount of actinomycetes. No significant difference was observed on the amount of ACDM between wet season and dry season. For the two forest types, the amounts of microbes and their biochemical activities in canopy humus had a larger seasonal variation range than those in understory humus. There was a significant difference in the amounts of the microbes in canopy humus among the dominant tree species in MMF and DMF, especially in wet season. The microbes in canopy humus played important roles in maintaining the biodiversity of epiphytes in the canopy, and in supplying the needed nutrients for the vigorous growth of the epiphytes.