Plant Microbe Research Articles

Prediction of olive tuberculosis through physicochemical characterisation of Pseudomonas savastanoi and surfaces of different olive tree parts

ABSTRACT This study examined plant–microbe interactions and surface contamination of olive trees by Pseudomonas savastanoi pv. savastanoi, the pathogen causing olive tuberculosis. Using XDLVO theory, we assessed the theoretical adhesion of P. savastanoi B97 cells to the bark, upper, and lower leaf surfaces of four olive cultivars based on physicochemical properties. Contact angle measurements revealed that lower leaf surfaces were more hydrophobic than upper leaf and bark surfaces, with a stronger electron donor character observed on the latter two. Lower leaf surfaces were identified as the preferred site for bacterial adhesion because of higher hydrophobicity. Among the cultivars, Arbicuina DOC and Arbicuina were most susceptible to colonisation. Conversely, cultivars with lower hydrophobicity and stronger electron donor properties, such as Haouzia and Moroccan Picholine, demonstrated greater resistance. These findings suggest that evaluating these properties can inform disease control strategies, promoting sustainable agriculture through resistant cultivars or targeted management of vulnerable surfaces.

Diversity and Function Patterns of Soil Microbial Communities in Native and Invasive Plants Along an Altitudinal Gradient in the Qinling Mountains

Soil microbial communities are essential drivers of ecosystem functions, yet the factors shaping their structure and function, particularly at different altitudes and between invasive and native plants, remain insufficiently understood. Using high-throughput Illumina sequencing, we assessed the composition, diversity, impact factors, and functional potential of the microbial communities associated with Galinsoga quadriradiata (an invasive species) and Artemisia lavandulifolia (a native species) across an altitudinal gradient ranging from 896 m to 1889 m in the Qinling Mountains. The results revealed that both plant species and altitude significantly influenced soil bacterial diversity and community structure. Actinobacteriota, Proteobacteria, and Acidobacteriota accounted for higher proportions in the soils of G. quadriradiata and A. lavandulifolia. A linear discriminant analysis showed that the two species hosted distinct microbial communities, with variations driven by species-specific traits and environmental factors. Compared with plant parameters, environmental factors had a greater impact on plant soil bacterial abundance. Functional analysis indicated that A. lavandulifolia soils were more associated with nitrogen cycling processes, while G. quadriradiata soils contributed more to organic matter decomposition. Therefore, invasive and native plants harbored microbial flora with different nutritional preferences and metabolic characteristics. These findings advance our understanding of plant–microbe interactions along altitudinal gradients, and they have practical implications for managing invasive species and supporting ecosystem resilience.

Rhizosphere Shifts: Reduced Fungal Diversity and Microbial Community Functionality Enhance Plant Adaptation in Continuous Cropping Systems

Continuous cropping problems constitute threats to perennial plant health and survival. Soil conditioners have the potential to enhance plant disease resistance in continuous cropping systems. However, how microbes and metabolites of the rhizosphere respond to soil conditioner addition remains largely unknown, but this knowledge is paramount to providing innovative strategies to enhance plant adaptation in continuous cropping systems. Here, we found that a biochar conditioner significantly improved plant survival rates in a continuous cropping system. The biochar-induced rhizosphere significantly alters the fungal community, causing a decline in fungal diversity and the downregulation of soil microbial community functionality. Specifically, the biochar-induced rhizosphere causes a reduction in the relative abundance of pathogenic Fusarium sp. and phenolic acid concentration, whose variations are the primary causes of continuous cropping problems. Conversely, we observed an unexpected bacterial diversity increase in rhizospheric and non-rhizospheric soils. Our research further identified key microbial taxa in the biochar-induced rhizosphere, namely, Monographella, Acremonium, Geosmithia, and Funneliformis, which enhance soil nutrient availability, suppress Fusarium sp., mitigate soil acidification, and reduce phenolic acid concentrations. Collectively, we highlight the critical role of regular microbial communities and metabolites in determining plant health during continuous cropping and propose a synthetic microbial community framework for further optimizing the ecological functions of the rhizosphere.

Endophytic Actinomycetes of Liliaceae Plants as Biocontrol Agents of Fusarium oxysporum f.sp. cepae Causes of Basal Plate Rot Disease on Shallots

Basal plate rot disease is one of the critical diseases in shallot plants. Control using synthetic chemical fungicides is still unable to overcome this problem, and it hurts the environment and reduces the population of essential microbes in plants. Endophytic actinomycetes have potential as biocontrol agents. They are reported to be able to inhibit the growth of pathogens, induce plant resistance, produce cell wall degrading enzymes, and promote growth. This research aims to obtain endophytic actinomycete isolates that have the potential to inhibit the growth of the fungus Fusarium. oxysporum f.sp. cepae causes of basal plate rot disease in shallot, and evaluate its inhibitory mechanism. Endophytic actinomycetes were isolated from tubers and roots of Liliaceae plants collected from shallots-production center area. The isolate obtained was tested for biosafety and continued with its inhibitory effectiveness against the fungus F. oxysporum f.sp. cepae in vitro, ability to induce resistance, and plant growth promotion test. The six best isolates were selected based on weighting using AHP and identified molecularly. The endophytic actinomycetes of Liliaceae plants can inhibit the growth of F. oxysporum f.sp. cepae up to 63.49% with an antibiosis mechanism, producing chitinase enzymes that cause lysis, induce resistance, and produce growth hormones such as IAA. Streptomyces sp. can inhibit the fungus F. oxysporum f.sp. cepae causes basal plate rot disease on shallot by producing antifungal compounds and chitinase enzymes, inducing resistance, and producing growth hormone.

Deciphering phenomics approaches for understanding plant–microbe interactions in nutrient absorption and utilization

Deciphering phenomics approaches for understanding plant–microbe interactions in nutrient absorption and utilization

Nectar‐inhabiting bacteria differently affect the longevity of co‐occurring egg parasitoid species by modifying nectar chemistry

AbstractFlowering plants can be introduced in modern agroecosystems to support resident natural enemies in the context of Conservation Biological Control (CBC). Buckwheat (Fagopyrum esculentum) (Polygonales: Polygonaceae) has been shown to enhance the longevity of several parasitoids through the provision of high quality and easily accessible floral nectar. Yet floral nectar is ubiquitously colonized by microbes which can change nectar chemistry with consequences for parasitoids. Nonetheless, how bacteria associated with buckwheat floral nectar affect parasitoid performance is not known. In this study, adult females of Trissolcus basalis (Hymenoptera: Scelionidae) and Ooencyrtus telenomicida (Hymenoptera: Encyrtidae), two parasitoids of Nezara viridula (Hemiptera: Pentatomidae), were provided with synthetic nectar fermented by 14 bacterial isolates originating from buckwheat nectar. We recorded the effect of bacterial fermentation on female longevity and nectar chemistry. In the case of T. basalis, females consuming nectar fermented by Bacillus sp., Brevibacillus sp., Brevibacterium frigoritolerans, Saccharibacillus endophyticus, and Terribacillus saccharophilus significantly enhanced their longevity compared with females fed with non‐fermented nectar. For O. telenomicida, enhanced longevity was recorded only in the case of B. frigoritolerans and Pantoea dispersa. For both parasitoids, no negative effects due to bacterial fermentation of nectar were recorded. Chemical investigations of bacteria‐fermented nectars revealed an increased diversity in the composition of sugars and sugar alcohols, whereas non‐fermented nectar only contained sucrose. Our findings show that nectar‐inhabiting bacteria are important “hidden players” in the interactions between flowers and parasitoids, an indication that a better understanding of plant–microbe–insect interactions could improve CBC programmes.

Molecular Communication of Microbial Plant Biostimulants in the Rhizosphere Under Abiotic Stress Conditions.

Microbial plant biostimulants offer a promising, sustainable solution for enhancing plant growth and resilience, particularly under abiotic stress conditions such as drought, salinity, extreme temperatures, and heavy metal toxicity. These biostimulants, including plant growth-promoting rhizobacteria, mycorrhizal fungi, and nitrogen-fixing bacteria, enhance plant tolerance through mechanisms such as phytohormone production, nutrient solubilization, osmotic adjustment, and antioxidant enzyme activation. Advances in genomics, metagenomics, transcriptomics, and proteomics have significantly expanded our understanding of plant-microbe molecular communication in the rhizosphere, revealing mechanisms underlying these interactions that promote stress resilience. However, challenges such as inconsistent field performance, knowledge gaps in stress-related molecular signaling, and regulatory hurdles continue to limit broader biostimulant adoption. Despite these challenges, microbial biostimulants hold significant potential for advancing agricultural sustainability, particularly amid climate change-induced stresses. Future studies and innovation, including Clustered Regularly Interspaced Short Palindromic Repeats and other molecular editing tools, should optimize biostimulant formulations and their application for diverse agro-ecological systems. This review aims to underscore current advances, challenges, and future directions in the field, advocating for a multidisciplinary approach to fully harness the potential of biostimulants in modern agriculture.

Wild again: recovery of a beneficial Cannabis seed endophyte from low domestication genotypes

BackgroundBeyond carrying the plant embryo, seeds harbour intricate microbial communities whose transmission across successive plant generations can significantly influence the ecological and evolutionary dynamics of plant–microbe symbioses. The process of plant domestication has potential repercussions in genes involved in plant-microbiome interactions. However, the extent to which breeding can impact the seed microbiome is sparsely explored. Cannabis is a high-value crop but sparsely subjected to agricultural innovations established in other crop species during the last century. Here, we conduct a large-scale analysis of the bacterial seed microbiome of Cannabis across different domestication grades and investigate the potential of seed-associated endophytes as plant growth-promoting agents under both controlled and field conditions.ResultsAnalysis of Cannabis seed endophyte composition and diversity across 46 plant genotypes revealed 813 different bacterial genera with a predominance of Gammaproteobacteria, Bacilli, Actinobacteria and Alphaproteobacteria but a genotype-specific microbiome. The assessment of domestication and breeding on microbial assembly revealed a higher bacterial diversity in low domestication genotypes (Shannon index, H′: 1.21 vs. 1.05) and a higher homogeneity in bacterial composition caused by line development. Further, a seed bacterial isolate (Bacillus frigoritolerans C1141) associated with low domestication genotypes, and with genes associated with bio-fertilization, bioremediation and phytohormone production, increased plant growth by 42.3% at the time of harvest, under field conditions.ConclusionThis study addresses critical knowledge gaps related to the assembly of the Cannabis seed-endophytic microbiome. It reveals that Cannabis breeding is linked to alterations of seed microbial communities, which potentially led to the loss of bacteria with functional significance. These results highlight the importance of preserving seed microbiomes in plant breeding to support sustainable plant health and growth enhancement in Cannabis.CAHvc7HPtw2foEoMit4yw-Video

Effects of sulfamethoxazole and copper on the natural microbial community from a fertilized soil

Cattle manure or its digestate, which often contains antibiotic residues, can be used as an organic fertilizer and copper (Cu) as a fungicide in agriculture. Consequently, both antibiotics and Cu are considered soil contaminants. In this work, microcosms were performed with soil amended with either manure or digestate with Cu and an antibiotic (sulfamethoxazole, SMX) co-presence and the planting of Lactuca sativa. After the addition of the organic amendments, a prompt increase in the microbial activity and at the same time of the sul1 and intI1 genes was observed, although ARGs generally decreased over time. In the amended and spiked microcosms, the microbial community was able to remove more than 99% of SMX in 36 days and the antibiotic did not bioaccumulate in the lettuce. Interestingly, where Cu and SMX were co-present, ARGs (particularly sul2) increased, showing how copper had a strong effect on resistance persistence in the soil. Copper also had a detrimental effect on the plant-microbiome system, affecting plant biomass and microbial activity in all conditions except in a digestate presence. When adding digestate microbial activity, biodiversity and lettuce biomass increased, with or without copper present. Not only did the microbial community favour plant growth, but lettuce also positively influenced its composition by increasing bacterial diversity and classes (e.g., Alphaproteobacteria) and genera (e.g., Bacillus), thus indicating a good-quality soil.Key points• Cattle digestate promoted the highest microbial activity, diversity, and plant growth• Cattle digestate counteracted detrimental contaminant effects• Cu presence promoted antibiotic cross-resistance in soilGraphical

Is the response of plant root systems to precipitation primarily driven by the rhizosphere soil?

BackgroundChanges in precipitation alter soil moisture, thereby affecting the aboveground and belowground ecological processes. However, it remains unclear whether plant root systems alter these effects through rhizospheric processes. In this study, a precipitation control experiment was conducted in the alpine grassland of northern Tibet to simulate precipitation changes with a 50% decrease and 50% increase in precipitation. Nutrient and microbial biomass, root traits, and survival strategies in the rhizosphere and bulk soils of the dominant plant, Stipa purpurea, were analyzed for alterations under precipitation changes.ResultsIncreased precipitation (IP) significantly decreased the rhizosphere soil total phosphorus and bulk soil ammonium nitrogen and increased the rhizosphere soil total potassium. Decreasing precipitation (DP) significantly increased the rhizosphere soil total potassium and decreased the bulk soil total potassium. DP significantly reduced microbial biomass carbon, nitrogen and phosphorus in rhizosphere soil, while IP significantly increased the bulk soil MBC:MBP, soil C:P imbalance, and soil N:P imbalance. Along the PC1 axis, where the contribution of the traits was relatively large, it was possible to define the root economic spectrum. The root system of Stipa purpurea from the DP treatment was distributed on the conservative side of the economic spectrum, whereas that from the control and IP treatments were clustered on the acquisition side.ConclusionsIncreasing and decreasing precipitation mainly affected the contents of total phosphorus and total potassium in rhizosphere soil and the contents of ammonium nitrogen and total potassium in bulk soil of Stipa purpurea. The microbial biomass carbon, nitrogen and phosphorus were mainly affected by a decrease in precipitation. Decreasing precipitation significantly reduced microbial biomass carbon, nitrogen and phosphorus, but the rhizosphere MBC:MBN, MBC:MBP and MBN:MBP remained stable under the change of precipitation. Increasing precipitation exacerbated the C:P imbalance and N:P imbalance in bulk soil, and increased the demand for phosphorus by bulk microorganisms. Increased precipitation promoted root access to resources. The root system of Stipa purpurea in the context of precipitation changes was driven by rhizosphere nutrients and bulk microorganisms. This study is important for revealing plant–microbe–soil interactions in terrestrial ecosystems.

Plants and microorganisms both contribute to soil organic matter formation through mineral interactions: Evidence from a subtropical forest succession

Understanding the formation and stabilization of soil organic carbon (SOC) is essential for predicting SOC dynamics. Traditionally, it was believed that SOC accumulates primarily through the selective retention of recalcitrant plant lignin components. However, an emerging hypothesis suggests that microbial necromass adsorbed onto mineral-associated soil fractions play a more significant role in promoting SOC formation. In this study, we tested the above hypothesis by investigating SOC content, particulate fraction (LF + POC) vs. mineral-associated fraction (MAOC), along with microbial necromass (amino sugars as biomarker) and plant lignin component (lignin phenols as biomarker) in the topsoil (0–20 cm) and subsoil (20–40 cm) across three successional stages: early coniferous forest, middle mixed forest and climax broadleaved forest in southern China. Results showed that SOC content increased with forest succession, accompanied by increasing contributions of MAOC in both soil layers. Interestingly, the contribution of microbial necromass to SOC increased throughout the succession only in the subsoil, whereas in the topsoil, it increased from the early to the middle stage, then slightly decreased at the climax stage. Additionally, the contributions of lignin phenols or LF + POC to SOC decreased in both soil layers with forest succession. A partial least squares path model further revealed that MAOC played a dominate role in governing SOC accumulation, driven by active mineral content combined with plant-derived dissolved organic matter in the topsoil and microbial necromass in the subsoil. Collectively, our findings suggest that plants and microorganisms contribute to SOC formation through interactions with minerals, unveiling an intricate interactive mechanism of plant–microbe-mineral continuum in SOC stabilization.

In vivo biocontrol potential of Bacillus plant growth-promoting rhizobacteria against pectinolytic plant pathogens.

Bacillus is well known for producing a wide range of compounds that inhibit microbial phytopathogens. From this perspective, we were interested in evaluating the biocontrol potential of 5 plant growth-promoting rhizobacteria Bacillus species (PGPR-Bacillus) on 21 microbial pectinolytic plant pathogens isolated from previous studies. Phytopathogenicity and in vivo biocontrol potential of PGPR curative and preventive treatments were investigated from this angle. Overall, the pathogenicity test on healthy tomato, zucchini, and mandarin showed low rot to no symptoms for all PGPR strain culture treatments. Conversely, zucchini pre-treated with PGPR strains B. circulans and B. cereus for 72h showed no signs of soft rot and remained healthy when in vitro contaminated with phytopathogens (Neisseria cinerea and Pichia anomala). Additionally, the PGPR-Bacillus strains were shown to be effective in mitigating the symptoms of soft rot in tomatoes, zucchini, and oranges using in vivo curative treatment. It is true that the majority of pectinolytic phytopathogenic strains exhibited antibiotic resistance. In vivo tests revealed that PGPR-Bacillus cell culture was effective against plant pathogens. Thus, PGPR-Bacillus can be considered a potential biocontrol agent for pectinolytic plant pathogens.

Pathological Characterization and Management of Lasiodiplodia theobromae, a Hemibiotroph with an Interkingdom Host Range.

Heart rot disease, caused by Lasiodiplodia theobromae, is destructive for date palms and other woody plants. The disease was reported in several oases in Egypt, and the pathogen was found in association with infected trees suffering dieback and rachis blight. Seven phylogenetically distinct fungal isolates were selected, and their pathogenicity was confirmed on date palms. The isolates exhibited variable degrees of virulence on inoculated leaves, which confirms the variation. We examined the antifungal effect of microbial bioagents and plant extracts on heart rot disease. The isolates of Trichoderma spp. gave moderate reduction of the pathogen's linear growth (40 to 60%), whereas their exudates were ultimately ineffective. Bacillus spp. isolates, except for B. megaterium, were more effective against spore germination, giving 80 to 90% reduction on average. Among the examined plant extracts, garlic sap gave 98.67% reduction of linear growth followed by artemisia (15.5%) and camphor (24.8%). The extraction methods greatly influenced the antifungal efficiency of each extract because exposure to organic solvents significantly decreased the efficiency of all extracts, whereas hot water extraction negatively affected garlic sap only. Successful bioagents and plant extracts were further assayed for the suppression of heart rot disease on date palms. Both T. album and T. harzianum gave comparable degrees of suppression as by commercial fungicides. In addition, treatment before or during pathogen inoculation was the most effective because it significantly enhanced the expression of defense-related enzymes. Our findings suggest biopesticides possess a dual role in disease suppression and defense boosters for date palms suffering heart rot disease.

Hot viewpoint on how soil texture, soil nutrient availability, and root exudates interact to shape microbial dynamics and plant health

Hot viewpoint on how soil texture, soil nutrient availability, and root exudates interact to shape microbial dynamics and plant health

Altitude Distribution Patterns and Driving Factors of Rhizosphere Soil Microbial Diversity in the Mountainous and Hilly Region of Southwest, China

The distribution characteristics of the microbial community in rhizosphere soils of different altitudinal gradients were explored to uncover ecological factors affecting microbial community composition. In this study, the community variations of bacteria and fungi in the rhizosphere soil of Chrysanthemum indicum L. were analyzed. Samples were distributed along an altitudinal gradient of 300–1500 m above sea level in the Fuling watershed of the Three Gorges Reservoir area, China. The analysis was conducted using Illumina MiSeq high-throughput sequencing and bioinformatics analyses. Through correlation analysis with ecological factors, the altitude distribution pattern and driving factors of soil microbial diversity in the mountainous and hilly region of Chongqing were explored. According to the results, the richness and diversity of rhizosphere soil bacteria increased with altitude, while fungi were the richest and most diverse at an altitude of 900 m. The composition of the microbial community differed among different altitudes. Actinobacteria, Proteobacteria, Acidobacteriota, Chloroflexi, Bacteroidota, Ascomycota, unclassified_k_Fungi, Basidiomycota, and Mortierellomycota dominated the microbial community in rhizosphere soil. Correlation analysis showed that the distribution of rhizosphere soil microbial communities correlated with soil ecological factors at different altitudes. Moisture, pH, total nitrogen, total potassium, available potassium, urease, and catalase were significantly positively correlated with rhizosphere soil bacterial α-diversity, while their correlations with fungi were not significant. Variation partition analysis showed that the combined effects of soil physical and chemical factors, enzyme activity, and microbial quantity regulated bacterial community structure and composition. Their combined contributions (19.21%) were lower than the individual effects of soil physical and chemical factors (48.49%), enzyme activity (53.24%), and microbial quantity (60.38%). The effects of ecological factors on fungal communities differed: While the soil physical and chemical factors (44.43%) alone had a clear effect on fungal community structures, their combined contributions had no apparent effect. The results of this study not only contribute to a deeper understanding of the impact mechanism of altitude gradient on the diversity of rhizosphere soil microbial communities, but also provide a scientific basis for the protection and management of mountainous and hilly ecosystems. It lays a foundation for the future exploration of the relationship between microbial communities and plant–soil interactions.

Effects of the Radicle Sheath on the Rhizosphere Microbial Community Structure of Seedlings in Early Spring Desert Species Leontice incerta

Most research on plant–microbe interactions emphasize the effects of micronutrients on the rhizosphere microbial community structure. However, the influence of seed structures, particularly the radicle sheath, on microbial diversity at the seedling root tips under varying temperatures and humidity has been less explored. This study conducted controlled indoor experiments in the northern desert of Xinjiang to assess the radicle sheath’s impact on microbial community composition, diversity, and function. The results indicated no significant changes in the Chao1 index for bacteria and fungi, but notable differences were observed in the Shannon and Simpson indices (p < 0.05). Under drought conditions, the radicle sheath significantly reduced bacterial infections without affecting fungi. Genus-level analysis showed an increased abundance of specific dominant bacterial groups when the radicle sheath was retained. NMDS analysis confirmed its significant effect on both bacterial and fungal community structures. LEfSe analysis identified 34 bacterial and 15 fungal biomarkers, highlighting the treatment’s impacts on microbial taxonomic composition. Functional predictions using PICRUSt 2 revealed that the radicle sheath facilitated the conversion of CH4 to CH3OH and various nitrogen cycle processes under drought. Overall, the radicle sheath plays a crucial role in maintaining rhizosphere microbial community stability and enhancing the functions of both bacteria and fungi under drought conditions.

Warm growing season activates microbial nutrient cycling to promote fertilizer nitrogen uptake by maize

The influence of nitrogen (N) inputs on soil microbial communities and N uptake by plants is well-documented. Seasonal variations further impact these microbial communities and their nutrient-cycling functions, particularly within multiple cropping systems. Nevertheless, the combined effects of N fertilization and growing seasons on soil microbial communities and plant N uptake remain ambiguous, thereby constraining our comprehension of the optimal growing season for maximizing crop production. In this study, we employed 15N isotope labeling, high-throughput sequencing, and quantitative polymerase chain reaction (qPCR) techniques to investigate the effects of two distinct growing seasons on microbial communities and maize 15N uptake ratios (15NUR). Our results showed that the warm growing season (26.6 °C) increased microbial diversity, reduced network complexity but enhanced stability, decreased microbial associations, and increased modularization compared to the cool growing season (23.1 °C). Additionally, the warm growing season favored oligotrophic species and increased the abundance of microbial guilds and functional genes related to N, phosphorus, and sulfur cycling. Furthermore, alterations in the characteristics of soil microbial keystone taxa were closely linked to variations in maize 15NUR. Overall, our findings demonstrate significant seasonal variations in soil microbial diversity and functioning, with maize exhibiting higher 15NUR during the warm growing season of the double cropping system.

Unravelling the microbiome of wild flowering plants: a comparative study of leaves and flowers in alpine ecosystems

BackgroundWhile substantial research has explored rhizosphere and phyllosphere microbiomes, knowledge on flower microbiome, particularly in wild plants remains limited. This study explores into the diversity, abundance, and composition of bacterial and fungal communities on leaves and flowers of wild flowering plants in their natural alpine habitat, considering the influence of environmental factors.MethodsWe investigated 50 wild flowering plants representing 22 families across seven locations in Austria. Sampling sites encompassed varied soil types (carbonate/silicate) and altitudes (450–2760 m). Amplicon sequencing to characterize bacterial and fungal communities and quantitative PCR to assess microbial abundance was applied, and the influence of biotic and abiotic factors assessed.ResultsOur study revealed distinct bacterial and fungal communities on leaves and flowers, with higher diversity and richness on leaves (228 fungal and 91 bacterial ASVs) than on flowers (163 fungal and 55 bacterial ASVs). In addition, Gammaproteobacteria on flowers and Alphaproteobacteria on leaves suggests niche specialization for plant compartments. Location significantly shaped both community composition and fungal diversity on both plant parts. Notably, soil type influenced community composition but not diversity. Altitude was associated with increased fungal species diversity on leaves and flowers. Furthermore, significant effects of plant family identity emerged within a subset of seven families, impacting bacterial and fungal abundance, fungal Shannon diversity, and bacterial species richness, particularly on flowers.ConclusionThis study provides novel insights into the specific microbiome of wild flowering plants, highlighting adaptations to local environments and plant–microbe coevolution. The observed specificity indicates a potential role in plant health and resilience, which is crucial for predicting how microbiomes respond to changing environments, ultimately aiding in the conservation of natural ecosystems facing climate change pressures.

Plant Functional Traits Modulate Effects of Drought on C:N:P Stoichiometry of Plant, Litter, and Soil Microbe in an Arid Grassland

Plant Functional Traits Modulate Effects of Drought on C:N:P Stoichiometry of Plant, Litter, and Soil Microbe in an Arid Grassland

Environmental Degradation Study of Polypropylene Films Incorporating Pro-Oxidants: Comprehensive Analysis and Ecotoxicological Assessment

Our research described in this paper investigated the environmental degradation of polypropylene (PP) films incorporating pro-oxidants and assessed their impact on the ecosystem. Weathering aging effects were monitored through Fourier-Transform Infrared (FTIR) analysis, revealing significant changes in carbonyl, hydroxyl and amorphous regions post-aging. The presence of pro-oxidants intensified these changes, indicating higher oxidation levels. Contact angle measurements demonstrated decreased hydrophobicity upon aging, particularly pronounced in pro-oxidant-containing films (initial contact angle: 87.79° for PP/1% Co/1% Fe, sample (F6) decreased to 79.24° after aging). Differential Scanning Calorimetric (DSC) analysis revealed decreased melting temperatures (initial Tm: 159.5 °C for F6 decreased to 148 °C after aging) and the crystallinity post-aging (initial χ: 73.25% for F6 decreased to 60.17% after aging), suggesting increased susceptibility to degradation. Thermogravimetric Analysis (TGA) showed decreased thermal stability after aging, especially in PP/pro-oxidant films; the Tonset (T5); 432.00 °C for F6, decreased to 268.00 °C after aging; where Tonset is the temperature corresponding to 5% weight loss. Biodegradation tests indicated enhanced biodegradability in the pro-oxidant-containing films, with cobalt and ferrous stearate mixtures showing the highest degradation degrees (e.g., PP/1% Co/1% Fe: ≈ 77% biodegradation after 140 days). Ecotoxicological evaluations, including microbial toxicity and plant germination and growth tests, revealed no inhibitory effects of the degradation products on soil flora or plant growth, confirming their nontoxic nature. Overall, we believe this comprehensive study provides insights into the environmental fate of PP films with pro-oxidants, highlighting their potential for accelerated degradation without adverse ecological impacts.