Microbes are ubiquitous in the rhizosphere and play crucial roles in plant health; however, the metabolisms and physiologies of individual species in planta remain poorly understood. In this study, we examined microbial gene expression in response to the maize root environment for seven bacterial species originally isolated from maize roots. We grew each species individually, both in vitro in a minimal medium and in planta, and used differential proteomics to identify functions upregulated specifically when bacteria are grown on maize roots. We identified between 1,500 and 2,100 proteins from each species, with 20%-60% of these proteins being differentially abundant between the two conditions. While we found that transporter proteins were upregulated in all species in planta, all other differentially abundant functions varied greatly between species, suggesting niche specialization in root-associated microbes. Indeed, in vitro assays confirmed that Curtobacterium pusillum likely degrades plant hemicellulose, Enterobacter ludwigii may benefit the plant by phosphate solubilization, and Herbaspirillum robiniae colonizes maize roots more effectively when both of its type VI secretion systems are functional. Together, our findings highlight both conserved and species-specific bacterial strategies for growth in the root environment and lay a foundation for future work investigating the mechanisms underlying plant-microbiota interactions.IMPORTANCEBacteria that live on and around plant roots are important for plant growth and health; however, we still know relatively little about how individual bacterial species behave in this environment. In this study, we looked at seven bacterial species originally isolated from maize roots to understand how they change their metabolism and physiology when grown on the plant versus when grown under laboratory conditions. By doing this, we identified key strategies that bacteria use to survive and thrive in the root environment, including changes in nutrient uptake, metabolism, and secretion systems. We also substantiated some of these behaviors using lab experiments and bacterial mutants. Understanding these species-specific functions helps us learn how bacteria establish themselves on roots and interact with the plant. This knowledge is critical for future efforts to design effective microbial communities that improve crop performance and resilience.
Tomato (Solanum lycopersicum L.) is a globally significant crop valued for its nutritional content and economic importance. This study evaluated the effect of individual and combined inoculation of two growth-promoting microorganisms in tomato: the entomopathogenic fungus Beauveria bassiana and the arbuscular mycorrhizal fungus Rhizophagus irregularis. The research was conducted in chamber conditions using tomato plants cultivar Elpida, at two developmental stages: seedlings and transplanted plants. Colonization of B. bassiana in plant tissues was confirmed by isolation from different organs, showing a higher presence in stems. mycorrhizal colonization was evident in roots, with the highest intensity in coinoculation treatments, which also showed greater formation of structures typical of symbiosis. Regarding growth, B. bassiana promoted greater leaf number and shoot biomass in seedlings, while R. irregularis favored root development, which is important for adaptation after transplanting. Coinoculation resulted in a significant increase in leaf area and mycorrhizal colonization, especially after transplanting, suggesting that the combination of these microorganisms can enhance the growth of tomato plants. The results indicate that early inoculation with B. bassiana and R. irregularis can be an effective strategy to improve plant development, although additional studies are required to evaluate long-term effects and final yield.
Plant viruses continue to impose severe constraints on global agriculture, often leading to substantial yield and economic losses. Conventional management strategies such as vector control and resistance breeding frequently fail to provide durable and broad-spectrum protection due to rapid evolution of virus, their dependence on host cellular machinery and the lack of effective antiviral compounds. These shortcomings have led researchers to increasingly explore molecular approaches, with RNA interference (RNAi) emerging as a precise and sustainable strategy for managing plant viral diseases. RNAi operates through endogenous gene regulatory mechanisms and is driven by small RNAs (sRNAs) such as small interfering RNAs (siRNAs) and microRNAs (miRNAs). Through mechanisms such as post-transcriptional gene silencing (PTGS) and transcriptional gene silencing (TGS), sRNAs orchestrate a robust and multilayered immune response against plant viruses. Recent advances have expanded RNAi-based strategies to both transgenic and non-transgenic platforms. Transgenic approaches such as host-induced gene silencing (HIGS), provide stable and long-term resistance, while non-transgenic methods like spray-induced gene silencing (SIGS) and other exogenous nucleic acid delivery systems offer flexible and environmentally safe alternatives without genetic modification. Furthermore, engineered sRNAs such as artificial microRNA (amiRNA) and synthetic trans-acting small interfering RNA (syn-tasiRNA) enhance target specificity, enable multiplex targeting and reduce off-target effects. This review aims to bridge the fundamental concepts of sRNA biology with their application in antiviral crop protection. It provides a comprehensive overview of sRNA biogenesis, antiviral mechanisms and engineered sRNA technologies for plant virus management.
Drought stress on vegetable crops significantly affect their plant growth and development resulting in reduced crop productivity and nutritional quality. Shallow root systems of the vegetable crops make them highly sensitive to drought stress. Therefore, sustainable drought mitigation strategies are required to alleviate drought stress for vegetable production under changing global environmental conditions. The current review focuses on key molecular mechanisms, including transcriptional factors and expression of stress-responsive genes, production of mitochondrial reactive oxygen species, modulation of signaling molecules, and circadian rhythm-mediated defense responses during onset of drought stress in vegetable crops. Further, plant-based mitigation strategies, such as use of phytomolecules, phytohormones, plant extracts, microbial endophytes, and drought-tolerant rootstocks from crop wild species for grafting onto vegetable crops are discussed for their role in enhancing drought resilience. Also, combining these strategies strengthens the antioxidant defense mechanism, osmotic homeostasis, and hormonal crosstalk under drought stress. Among the various strategies reported, phytomolecules, microbial endophytes, and drought-tolerant rootstocks from crop wild relatives are found to be promising for long-term field adaptations. The review further emphasizes future insights into plant-based solutions to enhance drought stress tolerance and integration of system biology approaches as well as field-based studies to develop climate-resilient, sustainable vegetable crop production system.
Country bean (Lablab purpureus L.) is an economically significant legume vegetable in Bangladesh, but its production is threatened by a new disease, web blight caused by Rhizoctonia solani. This study presented a comprehensive analysis of the pathogen's epidemiology, genetic diversity, physiology, host resistance, and chemical control strategies. Field surveys in six upazilas of Gazipur district revealed high disease prevalence (50%-80%), with incidence and severity ranging from 59%-92% to 38%-52%, respectively, peaking in October-November. Thirty isolates of R. solani were collected, and molecular characterization of four representative isolates identified AG-1 IA, AG-1 ID, and AG-5, indicating preliminary genetic variability among representative isolates. The detection of AG-1 ID and AG-5 is the first report on country bean. Optimal fungal growth occurred at 25°C-30°C and pH 7.0-9.0, with peptone, L-arginine, sodium nitrate, sorbitol, mannitol, and galactose as preferred nutrient sources. Maximum virulence, as measured by disease incidence, severity, and lesion development, was observed at 30°C. The pathogen exhibited a broad host range, infecting crops across Fabaceae, Poaceae, and Solanaceae. Screening of 94 country bean genotypes revealed a general lack of resistance, with most exhibiting moderate to high susceptibility. Among tested fungicides, Autostin 50 WG (carbendazim) and Nativo 75 WG (tebuconazole + trifloxystrobin) showed complete inhibition of mycelial growth in vitro. In planta application significantly reduced disease severity, achieving 83%-85% protection in preventive and 77%-81% in curative treatments, with efficacy lasting up to 15 days. These findings offer a novel insight into the web blight pathosystem in country bean, supporting the development of effective disease management strategies.
Tomato cultivation worldwide faces problems with bacterial wilt and Fusarium wilt, which cause significant yield losses. This study evaluated Bacillus sp. SNRUSA4, a polylactic acid (PLA)-degrading bacterium isolated from compost, for plant growth promotion and biocontrol against these diseases. In vitro assays confirmed that SNRUSA4 effectively inhibited Ralstonia solanacearum and Fusarium oxysporum f. sp. lycopersici, the pathogens responsible for bacterial wilt and Fusarium wilt, respectively. Important traits, including phosphate solubilization, nitrogen fixation, biofilm formation, and the production of siderophore, indole-3-acetic acid, ammonia, and hydrolytic enzymes (amylase, cellulase, lipase, protease, and chitinase), which are consistent with its PLA-degrading capability, were observed in SNRUSA4. These traits contribute to both plant growth promotion and disease suppression. The seedling tray experiment indicated that the combined application of SNRUSA4 and L-tryptophan synergistically promoted tomato seedling growth, enhancing shoot and root lengths. Seed priming with SNRUSA4 enhanced tomato seedling growth as shown in fresh weight, dry weight, and vigor index. SNRUSA4 demonstrated efficacy in the biocontrol of bacterial and Fusarium wilt diseases, along with promoting tomato growth in pot experiments. Thus, this study highlights the potential of Bacillus sp. SNRUSA4 as a multi-functional strain for bridging bioplastic waste management with tomato growth promotion and disease control.
Glycerophosphodiester phosphodiesterases (GDPDs) hydrolyze glycerophosphodiesters, phospholipid metabolites generated by acyl hydrolases. We analyzed the function of the two related proteins GDPD5 and GDPD6 from Arabidopsis (Arabidopsis thaliana), which are expressed during phosphate starvation and in flower organs. Heterologously expressed GDPD5 and GDPD6 hydrolyzed glycerophosphocholine and other glycerophosphodiesters, indicating that they are involved in the turnover of phosphatidylcholine (PC). The membrane lipid composition in leaves and roots of single gdpd5 or gdpd6 mutants was not altered during growth under normal conditions and phosphate starvation, suggesting that GDPD5 and GDPD6 are not involved in phospholipid turnover under phosphate starvation. After crossing gdpd5 and gdpd6 null mutants, no double homozygous (g5g5 g6g6) plants were obtained. Genetic analyses of the F1 progeny after selfing, or reciprocal crosses of G5g5 G6g6 with WT plants, revealed that the double heterozygous plants cannot produce viable female or male gametes with the haplotypes G5G6 or g5g6. About 50% of the seeds of G5g5 G6g6 plants were aborted. The development of microspores was affected, and ∼50% of pollen grains were distorted and lacked organelles. The anthers of G5g5 G6g6 plants showed decreased PC content, indicating that GDPD5 and GDPD6 are essential for PC homeostasis. Therefore, compromised PC homeostasis affects membrane biogenesis during sporogenesis and gametogenesis, compromising ovule and pollen viability in G5g5 G6g6 plants.
Soil salinity poses a major threat to global food security, impairing plant physiology through ionic toxicity, osmotic stress, and oxidative damage. However, conventional breeding and genetic engineering approaches face limitations due to the complexity of stress responses and regulatory hurdles. Nanotechnology, through the unique properties of nanomaterials (NMs), offers a promising alternative. This review synthesizes recent advances in nanoscale strategies for early salt stress sensing, the regulation of ion homeostasis, and reactive oxygen species scavenging. It further examines how NMs enhance nutrient use efficiency under saline conditions and discusses emerging applications in microbiome engineering and nontransgenic genetic improvements. The integration of machine learning to optimize NM design and application is also discussed. By synthesizing insights across these disciplines, this review provides a holistic framework for developing next-generation, nanotechnology-driven solutions to mitigate salinity stress, bridging the fundamental research with field-scale application for sustainable agriculture.
Climate change has increased the incidence of compound stresses, including the co-occurrence of nitrogen deficiency (-N) and high temperature (HT), which severely reduce plant productivity. Studies have primarily focused on single plant tissues to decipher tolerance mechanisms; however, tissue-specific metabolic reprogramming remains poorly examined. This work aimed to examine the distinct metabolic reprogramming in roots and leaves under whole-plant nitrogen deficiency (-N) and high temperature (HT), applied individually or combined. We hypothesized that roots and leaves exhibit complementary metabolic profiles, while combined stress triggers a unique metabolic signature associated with plant growth regulation. Soybean plants were subjected to control, -N, HT, and HT-N conditions, and later whole-plant physiological assessment and untargeted metabolites profiling of roots and leaves were performed and analyzed by machine learning analyses (e.g., t-SNE, UMAP, WGCNA, and random forest regression), qPCR and absolute quantification of identified key metabolites. Combined HT-N stress caused severe growth inhibition, reduced shoot length (67%), root fresh weight (52%), and photosynthetic efficiency (Fv/Fm; by 51%) compared to control. Metabolomic analysis revealed stress specific responses in different tissues, with roots prioritizing N assimilation (accumulating glutamate, proline and aspartate) under -N, while leaves enhanced osmo-protection (accumulating flavonoids) under HT. Under combined HT-N, tissue-specific responses were additive, with roots focusing on amino acid and proline metabolism and leaves on phenylpropanoid and glutathione metabolism. Our machine learning analyses (t-SNE, UMAP), WGCNA and RFR showed distinct tissue-specific metabolic signatures for each stress, and identified glucose, flavonoids, proline, and specific amino acids among key candidate metabolites associated with physiological resilience. Later, exogenous application of proline, quercetin, and L-arginine recovered soybean growth under stress, but in a stress-specific manner. Soybean employs distinct metabolic strategies in roots and leaves to manage multiple stresses. The identified key metabolites represent candidate hubs in the stress response network, offering candidate targets that warrant further investigation for breeding climate-resilient crops.
Phosphoinositide-specific phospholipases C (PI-PLC) are signaling enzymes that hydrolyze membrane phosphoinositides to generate lipid- and lipid-derived second messengers. In plants, PI-PLCs have been implicated in various physiological processes, including immunity. Tomato SlPLC2 was previously shown to be implicated in susceptibility to the necrotrophic fungus Botrytis cinerea. However, whether this observation extends to pathogens with different lifestyles and evolutionary origins remains unknown. Here, we investigated SlPLC2 function during infection with Phytophthora infestans, a globally devastating oomycete and causal agent of potato and tomato late blight. CRISPR-Cas9 knockout SlPLC2 plants showed significantly reduced disease symptoms, lower pathogen biomass, and decreased sporangia production, indicating impaired colonization. Upon infection, SlPLC2 knockout lines displayed attenuated expression of salicylic acid (SA)- and jasmonic acid (JA)-marker genes. Consistent with a role for PLC signalling in plant defense, early immune responses such as hydrogen peroxide accumulation and callose deposition were reduced in knockout plants. At the cellular level, these plants allow fewer infection vesicles formation by P. infestans, accompanied by an increase in expression of a biotrophy-associated effector gene PiAvrblb2, suggesting impaired establishment of infection. In Nicotiana benthamiana, SlPLC2-GFP displays a localization pattern predominately consistent with plasma membrane association and also localizes to the membranes surrounding P. infestans infection vesicles, where we also detected phosphoinositides PI4P and PI(4,5)P2. As complementary heterologous evidence, transient overexpression of SlPLC2 in Nicotiana benthamiana enhanced lesion development after P. infestans inoculations. Together, these findings identify SlPLC2 as a susceptibility factor associated with enhanced P. infestans colonization.
This study presents the synthesis, characterisation, and photocatalytic antifungal performance of a Cu+/Cu2+-TiO2 nanocomposite designed to control rice blast disease caused by Magnaporthe oryzae. The heterostructure was fabricated through a chemical precipitation process in which TiO2 was first doped with Cu2+ ions, followed by partial reduction to Cu+ to form CuI. X-ray Photoelectron Spectroscopy (XPS) confirmed the coexistence of both Cu+ and Cu2+ oxidation states. A notable feature of this material is its Cu+/Cu2+ redox cycling, which enhances charge separation during photocatalysis and supports the sustained production of reactive oxygen species (ROS), such as ●O2- and ●OH. These reactive species are intensified under visible-light LED irradiation, thereby imposing strong oxidative stress on the fungal pathogen. The optical bandgap energy (Eg) was calculated from UV-Vis diffuse reflectance spectra (DRS) using a Tauc plot method implemented in a Python-based analysis. Eg decreased systematically from 3.02 eV for pristine TiO2 to 2.67 eV for the optimized 3CuT3 composite. Correspondingly, the UV-Vis absorption edge exhibited a red shift from approximately 410-465 nm, indicating enhanced visible-light absorption. The 3CuT3 sample, containing the highest Cu loading (9.52 wt%), exhibited the strongest antifungal activity, achieving 91.55% inhibition of M. oryzae at 500 ppm after 10 days. In comparison, the 1CuT1 and 2CuT2 samples showed lower inhibition efficiencies of 78.22% and 83.55%, corresponding to their lower Cu contents of 2.73 wt% and 4.04 wt%, respectively. These findings suggest that the Cu species (Cu+/Cu2+) incorporated into the nanocomposite play a critical role in enhancing antifungal performance. This work provides a basis for further evaluation of the practical applicability and ecological safety of the Cu+/Cu2+-TiO2 nanocomposite for sustainable crop protection. ppm after 10 days. In comparison, the 1CuT1 and 2CuT2 samples showed lower inhibition efficiencies of 78.22% and 83.55%, corresponding to their lower Cu contents of 2.73 wt% and 4.04 wt%, respectively. These findings suggest that the Cu species (Cu+/Cu2+) incorporated into the nanocomposite play a critical role in enhancing antifungal performance. This work provides a basis for further evaluation of the practical applicability and ecological safety of the Cu+/Cu2+-TiO2 nanocomposite for sustainable crop protection.
To elucidate the light adaptation mechanism and optimal cultivation light regime for Paris polyphylla var. yunnanensis, a two-year continuous field positioning trial was conducted with five light gradients (20%, 40%, 60%, 80%, and 100% natural light, PAR = 300-2200 μmol·m-2·s-1). We systematically investigated the regulatory effects of light intensity on leaf phenotypic traits, anatomical and physiological functions, photosynthetic performance, vegetative growth and rhizome biomass accumulation. Significant differences in plant growth, leaf morphology and all functional trait indices were detected among the treatments (p < 0.05). The plants cultivated under 40%-60% natural light (PAR = 700-1400 μmol·m-2·s-1) exhibited balanced leaf anatomy, maximum photosynthetic efficiency and the highest rhizome fresh biomass. Compared with CK (100% natural light), plants under 40%-60% natural light showed 164.8% greater plant height, 35.5% thicker stem diameter, 50.0% larger rhizome diameter and 124.4% higher rhizome fresh weight. In contrast, 20% natural light induced excessive elongation, slender stems and underdeveloped mechanical tissues, with rhizome fresh weight, length and diameter decreasing by 52.2%, 61.4%, and 62.1%, respectively, relative to CK. Treatments of 80%-100% natural light triggered severe high-light stress, causing leaf scorch, chlorosis and suppressed stomatal development, with most assimilates allocated to antioxidant defense and thermal dissipation rather than rhizome carbon partitioning. In conclusion, P. polyphylla var. yunnanensis exhibits a clear light adaptation threshold with distinct gradient-specific responses: 80%-100% natural light induces photoinhibition and suppresses stomatal development; 20% natural light causes excessive elongation, slender stems and reduced rhizome biomass; while 40%-60% natural light optimizes leaf morphology, photosynthetic physiology and biomass allocation, resulting in the highest rhizome fresh weight (63.54-64.4  g) and overall growth performance. The 40%-60% natural light regime (PAR 700-1400 μmol·m-2·s-1) coordinates leaf morphogenesis, photosynthetic carbon fixation and dry matter accumulation, and is therefore identified as the optimal light condition for high-yield and high-quality medicinal production. This study provides quantitative light regulation parameters (PAR thresholds and corresponding growth responses) for understory bionic cultivation and precise light environment management in facility cultivation of this medicinal herb.
Improving protein accumulation without undesirable effects on plant growth remains an important goal in plant physiology and crop improvement. The orphan gene Qua-Quine Starch (QQS) from Arabidopsis thaliana increases protein and reduces starch across several plant species, but the downstream genes associated with these effects remain poorly defined. This study aimed to identify QQS-responsive genes in soybean (Glycine max) and determine whether they can reproduce the characteristic protein and starch phenotypes of QQS when expressed in A. thaliana. Previously published RNA-sequencing datasets from QQS-overexpressing (QQS-OE) Arabidopsis leaves and QQS-expressing (QQS-E) soybean leaves were compared to identify conserved differentially expressed genes. Nine soybean genes showing consistent QQS-responsiveness, including eight upregulated genes and one downregulated gene, were expressed individually in A. thaliana. Total protein was quantified in leaves and seeds, whereas starch was measured in leaves. Candidate promoters were analyzed for transcription factor motif enrichment, and the reporter activation capacity of DNA-tethered QQS was examined in yeast. The eight upregulated soybean genes significantly increased total protein and reduced starch in A. thaliana, whereas the downregulated gene produced the opposite phenotype, decreasing protein and increasing starch. Plant growth and morphology were largely unaffected. Candidate promoters shared motifs associated with nitrogen metabolism, sugar signaling, and plastidial functions. DNA-tethered QQS activated reporter expression in yeast, although this assay does not establish transcriptional activation with these soybean genes. These results identify a conserved QQS-responsive gene module that coordinately influences protein and starch accumulation and provides candidate genes for improving crop protein content.
Arbuscular mycorrhizal fungi (AMF) can improve plant performance under salinity, but their contribution to phenolic-based antioxidant responses in traditional tomato landraces remains unclear. We evaluated the effects of Diversispora celata and Funneliformis mosseae on growth, nutrition, gas exchange, oxidative status, and phenolic metabolism in Chilean tomato landraces Limachino and Maulino (Solanum lycopersicum L.) exposed to 0 or 150 mM NaCl. A 3 × 2 × 2 design included three inoculation treatments, two salinity levels, two landraces, and four replicates per combination. Biomass, shoot N and P contents, gas exchange, pigments, proline, lipid peroxidation, antioxidant capacity, and individual phenolics were quantified. Salinity reduced biomass, shoot N and P contents, and net photosynthesis, while non-mycorrhizal plants showed the highest lipid peroxidation. Responses depended on landrace and fungal identity. Under salinity, D. celata-inoculated Limachino plants showed higher biomass, shoot N content, and net photosynthesis than non-mycorrhizal plants, together with greater proline accumulation, higher concentrations of several hydroxycinnamic acids, anthocyanins, quercetin derivatives, total phenolics, and antioxidant capacity, and lower lipid peroxidation. In Maulino, both isolates improved gas exchange; F. mosseae was more closely associated with photosynthetic pigments and TEAC/DPPH capacity, and D. celata with phenolic derivatives and CUPRAC capacity. Overall, AMF responses depended on the host-fungus combination, with phenolic-associated non-enzymatic antioxidant responses emerging as a prominent feature of the Limachino-D. celata association.
Insights into phenotypic plasticity in leaf traits provide context for how plants maintain adequate resource acquisition across changing environments. Whether insertion mutations that influence early seedling rosettes translate into differences in reproductive success and phenotypic plasticity across nutrient and temperature environments is less known. We selected Arabidopsis thaliana mutant lines associated with a single insertion mutation in a common genetic background from a screen that categorized rosettes into two sets based on qualitative seedling size (increase or decrease) in comparison to wildtype and natural accessions. Our experiment under nutrient and temperature treatments showed the decrease set of mutant lines maintained smaller rosettes at bolting across environments, whereas the same was not found for the increase set, which revealed greater within-set variation. Nutrients increased fruit production, particularly at 20°C, whereas the warmer temperature (24°C) increased fruit abortion and tended to reduce fruit production, with stronger effects in the increase set. For the mutant lines studied for physiology, we found CO2 assimilation patterns were broadly similar across temperatures despite rosette size differences, suggesting that this aspect of physiology does not explain rosette differences. Treatment responses were not parallel across sets of lines, indicating substantial among-line variation. The variation in phenotypic traits across abiotic environments in single gene-insertion mutants offers new quantitative insights into tradeoffs between rosette and reproduction. With data on genetic mechanisms behind plasticity, our results highlight how individual mutations can generate context dependent variation in vegetative and reproductive traits and trait relationships, useful for informing other plants' responses to climate change.
Pollinator-mediated interactions shape the assembly and diversity of plant communities reliant on animal pollination. Such interactions can provide rare species with fitness advantages through facilitation while increasing intraspecific competition among abundant species. However, the roles of pollination generalisation and pollinator sharing in these dynamics remain unclear. To address this, we examined how plant rarity and pollination niche structure (breadth and overlap) influence pollination outcomes across 44 co-flowering species in Qinghai-Tibetan alpine grasslands. We measured plant abundance, floral traits, pollinator visitation, stigmatic pollen deposition, and seed production. Our results showed that rarer species exhibited broader pollination niches and greater niche overlap with co-flowering species, both associated with higher visitation and increased pollination outcomes. Pollination niche overlap, enhanced by greater floral trait similarity, emerged as a key mechanism promoting the persistence of rarer species through pollinator-mediated facilitation. Furthermore, asymmetric facilitation allowed rarer species to gain disproportionate conspecific pollen while abundant species experienced stronger intraspecific competition. Together, these results show that trait-mediated pollinator sharing enhances the persistence of rare species in pollinator-limited ecosystems and contributes to the maintenance of plant diversity.
The rapid expansion of the livestock sector has precipitated a substantial surge in animal feed demand, necessitating immediate exploration and development of alternative feed sources to ensure sustainable supply. Mulberry leaves (ML) and distillers' grains (DG) are by-products generated from agriculture and industry in Sichuan, China. Characterized by abundant output and favorable nutritional composition, two materials can be further processed to alleviate the shortage of feed resources. In this study, four strains including Bacillus subtilis, Saccharomyces cerevisiae, Levilactobacillus brevis and Lactiplantibacillus plantarum were mixed at three ratios: A (B. subtilis: S. cerevisiae: L. brevis = 1:1:1), B (B. subtilis: S. cerevisiae: L. plantarum = 1:1:1), and C (B. subtilis: S. cerevisiae: L. brevis: L. plantarum = 1:1:1:1). 10% inoculation rate was adopted for short-term anaerobic fermentation lasting 5 days using ML, DG and their mixed substrates (ML&DG) to optimize fermentation performance and modulate the microbial community structure. The results demonstrated that exogenous microbial inoculation effectively degraded tannin (50.81%) and phytic acid (52.66%), lowered the pH value below 4.77, and increased lactic acid content to 83.43 mg/g, which was 4.57 times higher than that of the control group. Meanwhile, the mixed fermentation of mulberry leaves and distillers' grains maintained a true protein retention rate of over 99% and retained antioxidant activity, with the ABTS radical scavenging capacity of the mixed substrates reaching 114.35% relative to the initial level. Microbial analysis confirmed Lactobacillus as the dominant genus correlating with quality enhancement. This study demonstrates the efficient bio-conversion of ML and DG into high-nutrient feed via solid-state fermentation using mixed fermentation and a designed microbial consortium. This waste-to-feed strategy establishes a sustainable model for circular agriculture by transforming low-value residues into functional feed resources.
Pollinators are declining globally due to anthropogenic pressures, such as intensive grazing and nutrient enrichment. Yet, their combined effects on pollinators and plant-pollinator interactions remain poorly understood, particularly in the Arctic. Here, we experimentally tested how grazing exclusion and nutrient addition shape flower-visiting insect communities and interaction networks in a high-productivity montane and a low-productivity tundra grassland, in northern Fennoscandia. Grazing exclusion emerged as the primary driver across both grasslands, increasing flower-visitor family richness, diversity, and the number of plant-pollinator interactions. These effects were especially strong in the tundra grassland, where resource limitation is more pronounced. In contrast, nutrient addition had weaker and more context-dependent effects, enhancing flower-visitor richness and the number of interactions mainly in the tundra grassland and particularly when combined with grazing exclusion. At both sites, grazing exclusion and nutrient addition altered community composition, with the strongest shifts occurring under their combined effects. Despite large effects on interaction numbers, network structure responded more subtly. Weighted connectance declined with grazing exclusion, especially in the tundra, indicating that interactions became more concentrated on a subset of plant species where floral resources were abundant. In contrast, network specialization (H2') and nestedness showed limited responses to experimental treatments, suggesting relatively stable interaction organization. Overall, our results demonstrate that grazing strongly regulates pollinator communities and interaction networks in Arctic grasslands, while nutrient enrichment plays a secondary, context-dependent role. The pronounced sensitivity of tundra grasslands highlights their vulnerability to environmental change and underscores the importance of managing grazing pressure to sustain pollination processes in Arctic ecosystems.
Drought stress is one of the important factors limiting the growth of the apple industry. Although 5-hydroxytryptamine (5-HT), an ancient indole amine, is widely present in plants, the role of 5-HT in drought stress in apples is unknown. We tested the impact of 5-HT on long-term drought stress in apple seedlings. Our findings revealed that 1 μM of exogenous 5-HT could improve the resistance of apple seedlings to short- and long-term drought stress. These plants experienced better root growth, more efficient water use, and less reactive oxygen species (ROS). The higher ABA levels mediated by 5-HT in leaves increased stomatal density and improved the photosynthetic capacity of leaves. Furthermore, exogenous 5-HT boosted the expression of drought stress-related genes, enabling apple plants to adapt to drought stress.