In the context of global climate change, exploring how plant adaptation and responses to drought vary among different regions are crucial to understanding and predicting its geographic distribution. In this study, to explore the drought adaptation and responses of the dominant species in the semi-arid Eurasian Steppes and their differences among the different regions in terms of growth, physiology, and RNA-seq transcriptome, was chosen as the study material, and a seed source (three regions: eastern, middle, and western regions) × soil moisture treatment (three treatments: control, light drought, and heavy drought) two-factor experiment was conducted. (1) Four growth traits for individuals from the western region were significantly lower than those from the other two regions.
View Article and Find Full Text PDFBackground: Epichloë endophytes provide many benefits to host plants, including enhanced insect resistance. Fungal alkaloids are usually thought to be responsible for the endophyte-conferred herbivore resistance. Nonetheless, the fungal alkaloid profiles and concentrations may vary considerably among grass-endophyte systems.
View Article and Find Full Text PDFExploring how interactions between species evenness and dominant species identity affect litter decomposition processes is vital to understanding the relationship between biodiversity and ecosystem functioning in the context of global changes. We carried out a 127-day litter decomposition experiment under controlled conditions, with interactions of four species evenness types (high, medium, low and single species) and three dominant species identity (, , ). After collecting the remaining litter, we estimated how evenness and dominant species identity affected litter mass loss rate, carbon (C) loss rate, nitrogen (N) loss rate and remaining litter C/N directly or indirectly, and assessed relative mixture effects (RMEs) on litter mass loss.
View Article and Find Full Text PDFIn plant-herbivore interactions, plant volatile organic compounds (VOCs) play an important role in anti-herbivore defense. Grasses and Epichloë endophytes often form defensive mutualistic symbioses. Most Epichloë species produce alkaloids to protect hosts from herbivores, but there is no strong evidence that endophytes can affect the insect resistance of their hosts by altering VOC emissions.
View Article and Find Full Text PDFUnderstanding patterns of intraspecific trait variation can help us understand plant adaptability to environmental changes. To explore the underlying adaptation mechanisms of zonal plant species, we selected seven populations of , a dominant species in the Inner Mongolia Steppe of China, and evaluated the effects of phenotypic plasticity and genetic differentiation, the effects of climate variables on population trait differentiation, and traits coordinated patterns under each soil moisture treatment. We selected seeds from seven populations of in the Inner Mongolia Steppe, China, and carried out a soil moisture (2) × population origin (7) common garden experiment at Tianjin City, China, and measured ten plant traits of .
View Article and Find Full Text PDFIntroduction: Increases in plant species diversity may increase the community diversity effect and produce community over-yielding. Epichloë endophytes, as symbiotic microorganisms, are also capable of regulating plant communities, but their effects on community diversity effects are often overlooked.
Methods: In this experiment, we investigated the effects of endophytes on the diversity effects of host plant community biomass by constructing artificial communities with 1-species monocultures and 2- and 4-species mixtures of endophyte-infected (E+) and endophyte-free (E-) Achnatherum sibiricum and three common plants in its native habitat, which were potted in live and sterilized soil.
Exploring how plant-plant interactions between species and their neighbors vary with biotic and abiotic factors is vital to understanding community assembly mechanisms in the context of global changes. In this study, using a dominant species (Leymus chinensis (Trin.) Tzvel.
View Article and Find Full Text PDFAchnatherum sibiricum can be infected by two species of fungal endophytes, Epichloë gansuensis (Eg) and Epichloë sibirica (Es). In this study, the metabolites of Eg, Es, and their infected plants were studied by GC−MS analysis. The results showed that the metabolic profiles of Eg and Es were similar in general, and only six differential metabolites were detected.
View Article and Find Full Text PDFendophytes can improve the resistance of host grasses to pathogenic fungi, but the underlying mechanisms remain largely unknown. Here, we used phytohormone quantifications, gene expression analysis, and pathogenicity experiments to investigate the effect of on the resistance of to pathogens. Comparison of gene expression patterns between endophyte-infected and endophyte-free leaves revealed that endophyte infection was associated with significant induction of 1,758 and 765 differentially expressed genes in the host before and after pathogen inoculation, respectively.
View Article and Find Full Text PDFBiodiversity changes in terrestrial communities continue in the context of global changes. However, the interactive effects of the changes in diversity at inter- and intraspecific levels as well as cascading effects from plant to soil microorganisms on ecosystem functioning under climate changes remains largely unexplored. Using grassland species in the semi-arid Inner Mongolia Steppe, we conducted a microcosm experiment to assess how drought treatment (non-drought and drought conditions), species diversity (2, 4, and 7 species) and genotypic diversity of the dominant species Leymus chinensis (1, 3, and 6 genotypes) affected ecosystem functions directly or indirectly via regulating plant community functional structure [community-weighted mean (CWM) and functional dispersion (FDis)] and soil microbial diversity (Shannon-Wiener index).
View Article and Find Full Text PDFEpichloë endophytes can not only affect the growth and resistance of the host plant but also change the biotic and abiotic properties of the soil where the host is situated. Here, we used endophyte-infected (EI) and endophyte-free (EF) Leymus chinensis as plant materials, to study the microbial diversity and composition in the host root endosphere and rhizosphere soil under both pot and field conditions. The results showed that endophyte infection did not affect the diversity of either bacteria or fungi in the root zone.
View Article and Find Full Text PDFBoth species (interspecific) richness and genotype (intraspecific) richness of dominant species have significant effects on ecosystem functioning directly or indirectly by regulating plant community functional structure. However, the similarities and differences of the effects between inter- and intraspecific levels are poorly understood. In this study, we selected the main species in the semi-arid Eurasian typical steppe as study objects and simultaneously carried out a species richness experiment and a genotype richness experiment of which is one of the dominant species in this region.
View Article and Find Full Text PDFUnderstanding relationships between biodiversity and ecosystem functions (BEF) and the way in which ecosystem functions respond to changing climatic conditions or community composition is useful for predicting ecological consequences of global changes. However, how soil moisture condition, plant species richness interactively affect ecosystem functions in shrub-encroached grasslands is poorly understood. We conducted a soil moisture × species richness microcosm experiment using semi-arid grassland species with a N-fixing shrub Caragana microphylla Lam.
View Article and Find Full Text PDFIn artificial ecosystems, mixed planting of gramineous and leguminous plants can have obvious advantages and is very common. Due to their improved growth performances and stress tolerance, endophyte-infected grasses are considered to be ideal plant species for grasslands. However, endophytic fungi can inhibit the growth of neighboring nonhost leguminous plants.
View Article and Find Full Text PDFIt is well documented that endophytes can enhance the resistance of grasses to herbivory. However, reports on resistance to pathogenic fungi are limited, and their conclusions are variable. In this study, we chose pathogenic fungi with different trophic types, namely, the biotrophic pathogen species and the necrotrophic pathogen , to test the effects of on the pathogen resistance of .
View Article and Find Full Text PDFEndophytes of grasses have been reported to affect the colonization by arbuscular mycorrhizal fungi (AMF) not only of their dual host plant but also of neighboring non-endophyte-infected plants. However, studies investigating the impact of AMF identity on the effects of endophyte-infected grasses on neighboring plants are rare. In this study, we investigated the influence of Leymus chinensis litter type (NL, no litter; E-, endophyte-free litter; E-E+, half E+ and half E- litter; E+, endophyte-infected litter) on Stipa krylovii growth with different AMF species (Claroideoglomus etunicatum, CE; Funneliformis mosseae, FM; Claroideoglomus claroideum, CC; Rhizophagus intraradices, RI).
View Article and Find Full Text PDFEpichloë endophytes may not only affect the growth and resistances of host grasses, but may also affect soil environment including soil microbes. Can Epichloë endophyte-mediated modification of soil microbes affect the competitive ability of host grasses? In this study, we tested whether Epichloë endophytes and soil microbes alter intraspecific competition between Epichloë endophyte-colonized (EI) and endophyte-free (EF) and interspecific competition between and . The results demonstrated that Epichloë endophyte colonization significantly enhanced the intraspecific competitive ability of and that this beneficial effect was not affected by soil microbes.
View Article and Find Full Text PDFUnderstanding community assembly mechanisms is helpful to predict community dynamics. To explore which community assembly mechanism(s) drive(s) the grassland restoration in semi-arid region, we investigated the relationships between plant trait and species relative abundance (SRA), and estimated community functional diversity indices for each community under different treatments (enclosure, grazing and mowing treatment) in a restoration region of Stipa grandis - Leymus chinensis communities in the northern China from 2010 to 2012. There was a high fraction of significant relationships between trait value and SRA, suggesting that niche theory structured the grassland restoration in this region.
View Article and Find Full Text PDFGrasses often establish multiple simultaneous symbiotic associations with endophytic fungi and arbuscular mycorrhizal fungi (AMF). Many studies have examined pair-wise interactions between plants and endophytic fungi or between plants and AMF, overlooking the interplays among multiple endosymbionts and their combined impacts on hosts. Here, we examined both the way in which each symbiont affects the other symbionts and the tripartite interactions between leaf endophytic fungi, AMF, and Leymus chinensis.
View Article and Find Full Text PDFStudies have indicated that plant litter diversity can affect litter decomposition at both species diversity and genotypic diversity level within a species. However, the essence and relative importance of these two diversity levels on litter decomposition remain unknown. Here, two independent one-factor experiments, litter species diversity and litter genotypic diversity of the dominant species-Stipa grandis, were carried out to explore the effects of initial litter quality, litter composition and diversity on decomposition of mass, nitrogen (N), carbon (C) and phosphorus (P) simultaneously.
View Article and Find Full Text PDFPlant-plant interactions play a key role in the function and structure of communities. The combined effect of drought stress and grazing disturbance on shaping plant-plant interactions is still poorly understood, while this combination is common in semiarid ecosystems. Four species including , which is dominant in the typical steppe, and , and , which are dominant species in the degraded communities, were selected as study targets.
View Article and Find Full Text PDFAlkaloids are usually thought to be responsible for protecting endophyte-infected (EI) grasses from their herbivores. For EI grasses that produce few alkaloids, can endophyte infection enhance their resistance to herbivores? Related studies are limited. In the Inner Mongolian steppe, is highly infected by endophytes, but produces few alkaloids.
View Article and Find Full Text PDFWhether plants are able to adapt to environmental changes depends on their genetic characteristics and phenotypic plastic responses. We investigated the phenotypic responses of 7 populations of an important dominant species in semi-arid steppe of China - Stipa grandis, and then distinguished which adaptive mechanism(s), phenotypic plasticity or local adaptation, was/were involved in this species to adapt to environmental changes. (1) All traits were significantly influenced by the interaction of population and growth condition and by population in each condition, and inter-population variability (CV) was larger in the field than in the common garden for 8/9 traits, indicating that both phenotypic plasticity and genetic differentiation controlled the phenotypic differences of S.
View Article and Find Full Text PDFGrasses can be infected simultaneously by endophytic fungi and arbuscular mycorrhizal (AM) fungi. In this study, we tested the hypothesis that endophyte-associated drought resistance of a native grass was affected by an AM fungus. In a greenhouse experiment, we compared the performance of endophyte-infected (EI) and endophyte-free (EF) Leymus chinensis, a dominant species native to the Inner Mongolia steppe, under altered water and AM fungus availability.
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