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Sclerotinia sclerotiorum (Lib.) de Bary is the causative agent of stem white mold disease which severely reduces major crop productivity including soybean and rapeseed worldwide. The current study aimed to explore plant growth-promoting traits and biocontrol of new isolated Bacillus subtilis BS-2301 to suppress S. sclerotiorum through various mechanisms. The results indicated that the BS-2301 exhibited strong biocontrol potential against S. sclerotiorum up to 74% both in dual culture and partition plate experiments. The BS-2301 and its crude extract significantly suppressed S. sclerotiorum growth involving excessive reactive oxygen species (ROS) production in mycelia for rapid death. Furthermore, the treated hyphae produced low oxalic acid (OA), a crucial pathogenicity factor of S. sclerotiorum. The SEM and TEM microscopy of S. sclerotiorum showed severe damage in terms of cell wall, cell membrane breakage, cytoplasm displacement, and organelles disintegration compared to control. The pathogenicity of S. sclerotiorum exposed to BS-2301 had less disease progression potential on soybean leaves in the detached leaf assay experiment. Remarkably, the strain also demonstrated broad-range antagonistic activity with 70%, and 68% inhibition rates against Phytophthora sojae and Fusarium oxysporum, respectively. Furthermore, the strain exhibits multiple plant growth-promoting and disease-prevention traits, including the production of indole-3-acetic acid (IAA), siderophores, amylases, cellulases and proteases as well as harboring calcium phosphate decomposition activity. In comparison to the control, the BS-2301 also showed great potential for enhancing soybean seedlings growth for different parameters, including shoot length 31.23%, root length 29.87%, total fresh weight 33.45%, and total dry weight 27.56%. The antioxidant enzymes like CAT, POD, SOD and APX under BS-2301 treatment were up-regulated in S. sclerotiorum infected plants along with the positive regulation of defense-related genes (PR1-2, PR10, PAL1, AOS, CHS, and PDF1.2). These findings demonstrate that the BS-2301 strain possesses a notable broad-spectrum biocontrol potential against different phytopathogens and provides new insight in suppressing S. sclerotiorum through various mechanisms. Therefore, BS-2301 will be helpful in the development of biofertilizers for sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

The goal of the current study is to better understand how bacteria may adapt to survive under adverse environmental conditions by altering and improving their phenotypes. In this study, we report the consequences of phenotypic variation in Paenibacillus polymyxa E681 (E681), a plant growth-promoting rhizobacterium (PGPR), isolated from winter barley root that has a variety of advantageous effects on crop plants. In our previous study, two different types of bacterial cells in E681 were distinguished. We used the term F-type for the variant that doesn't produce endospores and B-type for the endospore-producing wild type. Under the circumstances of our experiment, the cucumber rhizosphere soil and the surface of the seeds produced phenotypic variance. On tryptic soy agar (TSA) plates, the B-type spontaneously converted into the F-type, but the reverse was not reversible. Intriguingly, the plant growth promotion test displayed that cucumber seedlings treated with F-type cells had characteristics resembling those of the untreated control. Whereas, growth promotion of cucumber seedlings treated with B-type depends on temperature conditions. In particular, an increased growth promotion was observed at a low temperature of 20°C. The phenotypic change from B-type to F-type did not occur at 20°C for 6 days in the growth curve analysis of E681, but it did occur on the fourth and second days at 30 and 37°C, respectively. Therefore, before using PGPR strains as a bacterial inoculant for sustainable agriculture, it is imperative to resolve phenotypic variance in these strains. [ABSTRACT FROM AUTHOR]

This study evaluates the biocontrol efficacy of three bacterial strains (Pseudomonas fluorescens DTPF-3, Bacillus amyloliquefaciens DTBA-11, and Bacillus subtilis DTBS-5) and two fungal strains (Trichoderma harzianum Pusa-5SD and Aspergillus niger An-27) antagonists, along with their combinations at varying doses (5.0, 7.5, and 10.0 g/kg of seeds), against wheat powdery mildew. The most effective dose (10 g/kg seeds) was further analyzed for its impact on induced resistance and plant growth promotion under greenhouse conditions. The study measured defense enzyme activities, biochemical changes, and post-infection plant growth metrics. All tested microbial antagonists at 10 g/kg significantly reduced PM severity, with B. subtilis strain DTBS-5 outperforming others in reducing PM severity and achieving the highest biocontrol efficacy. It was followed by B. amyloliquefaciens strain DTBA-11 and P. fluorescens strain DTPF-3, with the fungal antagonists showing no significant effect. Wheat crops treated with B. subtilis strain DTBS-5 exhibited substantial increases in defense-related enzyme activities and biochemicals, suggesting an induced resistance mechanism. The study found a 45% increase in peroxidase (POD) activity, a 50% increase in catalase (CAT) activity, a 30% increase in phenolic content, and a 25% increase in soluble protein content in the wheat plants treated with microbial antagonists. The study highlights the effectiveness of microbial antagonists, particularly B. subtilis strain DTBS-5, in managing wheat PM through biocontrol, induced resistance, and enhanced plant growth, offering a sustainable alternative to chemical treatments. [ABSTRACT FROM AUTHOR]

BACKGROUND: Saccharomyces cerevisiae plays a pivotal role in various industrial processes, including bioethanol production and alcoholic beverage fermentation. However, during these fermentations, yeasts are subjected to various environmental stresses, such as ethanol stress, which hinder cell growth and ethanol production. Genetic manipulations and the addition of natural ingredients rich in antioxidants to the culture have been shown to overcome this. Here, we investigated the potential of persimmon tannins, known for their antioxidative properties, to enhance the ethanol stress tolerance of yeast. RESULTS: Assessment of the effects of 6.25 mg mL−1 persimmon tannins after 48 h incubation revealed cell viability to be increased by 8.9‐ and 6.5‐fold compared to the control treatment with and without 12.5% ethanol, respectively. Furthermore, persimmon tannins reduced ethanol‐induced oxidative stress, including the production of cellular reactive oxygen species and acceleration of lipid peroxidation. However, persimmon tannins could hardly overcome ethanol‐induced cell membrane damage. CONCLUSION: The findings herein indicate the potential of persimmon tannin as a protective agent for increasing yeast tolerance to ethanol stress by restricting oxidative damage but not membrane damage. Overall, this study unveils the implications of persimmon tannins for industries relying on yeast. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Soy molasses, a by-product from the processing of soy protein concentrate, is a low-cost feedstock for fermentation processes due to its high content of fermentable sugars. This work investigates the use of soy molasses for growing Bacillus species, aiming at their potential application as plant growth promoters. Firstly, six Bacillus strains were screened for their ability to grow in increasing concentrations of soy molasses in a microplate assay. Following this, shaken-flask assays for growth and γ-polyglutamic acid (γ-PGA) production by three Bacillus strains in medium E and soy molasses media with 28 and 56 g L−1 of total reducing sugars (TRS) were carried out. An in vivo experiment evaluated the effect of the bacterial fermented broths on the germination and initial development of maize. Soy molasses supported the growth of Bacillus amyloliquefaciens, Bacillus subtilis, and Bacillus licheniformis in concentrations of 28 and 56 g L−1 TRS, but it was inhibitory at 112 and 224 g L−1 TRS. In soy molasses media, growth was not always associated with γ-PGA production, which was a maximum of 56 g L−1 TRS for B. amyloliquefaciens and B. licheniformis. Fermented broths with B. subtilis and B. licheniformis in soy molasses media (56 and 28 g L−1 TRS, respectively) applied to maize seeds resulted in the highest Vigor Indexes of the seedlings, which correlated negatively with the broth pH and were not impacted by the γ-PGA and indole acetic acid produced by the bacteria. The low-cost and easily available feedstock soy molasses constitutes a potential culture medium for the growth of plant growth-promoting bacteria. [ABSTRACT FROM AUTHOR]

The Pisha sandstone area in the Yellow River Basin is one of the regions with the most severe soil erosion in China and globally, and its erosion is particularly challenging to control. W-OH, a hydrophilic polyurethane material, possesses controllable degradation properties. It can react with water to achieve soil stabilization and erosion resistance during the curing process. The material has been successfully utilized in erosion control in Pisha sandstone areas. This study aims to investigate the impact of W-OH material on water/fertilizer retention and plant growth through experiments on soil hardness, permeability, soil evaporation, soil column leaching, pot tests, and a small-scale demonstration in practical engineering applications. The results indicate that different concentrations of W-OH solution can effectively permeate Pisha sandstone, solidifying the particles to create a flexible and porous consolidation layer on the surface with a specific depth. As the W-OH concentration (3%, 4%, and 5%) increases, the harnesses of the consolidation layer also increase but remain below 1.5 kPa, which does not impede plant root growth. The soil evaporation rate decreased by approximately 45.2%, 45.8%, and 50.3% compared to the control group. The reduction rates of cumulative total nitrogen (TN) content are around 43.57%, 48.14%, and 63.99%, and, for cumulative total phosphorus (TP), are approximately 27.96%, 45.70%, and 61.17% under the 3%, 4%, and 5% concentrations of W-OH solution, respectively. In the pot tests, concentrations of W-OH solution below 5% are suitable for germination and growth of monocotyledons, while the optimal concentration for dicotyledons is around 3%. In the demonstration, the vegetation coverage of the treated gully increases by approximately 11.35%. This research offers a promising and effective approach to enhance ecological restoration in Pisha sandstone areas. [ABSTRACT FROM AUTHOR]

While confronted with unfavorable growth conditions, bacteria may transform into the dormant state, such as viable but nonculturable (VBNC) state, which is a reversible state characterized by low metabolic activity and lack of division. These dormant cells can be reactivated through the influence of the resuscitation promoting factor (Rpf) family, which are classified as autocrine growth factors and possess peptidoglycan hydrolase activities. To date, with the significant resuscitation or growth promotion ability of Rpf, it has been extensively applied to increasing bacterial diversity and isolating functional microbial species. This review provides a comprehensive analysis of the distribution, mode of action, and functional mechanisms of Rpf proteins in various bacterial species. The aim is to create opportunities for decoding microbial communities and extracting microbial resources from real samples across different research fields. [ABSTRACT FROM AUTHOR]

Recent studies have highlighted several advantages in using well-formulated blends of plant growth-promoting rhizobacteria (PGPR) that promote synergistic interactions over single PGPR strains. However, developing PGPR consortia (i.e., blends) that are effective in multiple crop cultivars is challenging. Five PGPR blends were evaluated for broad-spectrum growth promotion efficacy. Rhizosphere bacteria were isolated from crops grown in Texas to identify indigenous PGPR strains, and those with biological activity against fungal pathogens were used to formulate three PGPR blends, hereafter called TX1, TX2 and TX3. Using two corn and two cotton cultivars of contrasting resistance levels to fungal pathogens, the efficacy of these three PGPR blends was compared to two previously reported blends (AU9 and AU8). In addition, effects of the PGPR blends on the crops' transpiration rate and stomatal conductance were evaluated. The newly identified PGPR strains belong to five bacterial taxonomic groups: Bacillus, Paenibacillus, Pantoea, Peribacillus and Priestia. All PGPR blends increased the length and weight of root and shoot of the susceptible cultivars. For the resistant cultivars, blends AU8, TX1, TX2 and TX3 enhanced at least one of the corn growth parameters, while only TX2 and TX3 increased growth of the cotton plants. Resistant corn plants treated with AU8, TX1, TX2 or TX3 blend, and resistant cotton plants treated with AU8 or TX3 blend showed increased transpiration rate and stomatal conductance compared with untreated plants, but no significant differences were observed for the susceptible cultivars. The findings indicate that the PGPR blends showed better growth promotion efficacy in susceptible cultivars than in resistant cultivars. Only blends TX2 and TX3 made of PGPR strains from across four and three bacterial taxonomic groups, respectively, significantly increased growth of all four cultivars, regardless of resistance levels, suggesting that these blends have a great potential to enhance growth of a broad range of corn and cotton cultivars. [ABSTRACT FROM AUTHOR]

The importance of microorganisms residing within the host plant for their growth and health is increasingly acknowledged, yet the significance of microbes associated with seeds, particularly seed endophytic bacteria, remains underestimated. Seeds harbor a wide range of bacteria that can boost the growth and resilience of their host plants against environmental challenges. These endophytic associations also offer advantages for germination and seedling establishment, as seed endophytic bacteria are present during the initial stages of plant growth and development. Furthermore, plants can selectively choose bacteria possessing beneficial traits, which are subsequently transmitted through seeds to confer benefits to future generations. Interestingly, even with the ongoing discovery of endophytes in seeds through high-throughput sequencing methods, certain endophytes remain challenging to isolate and culture from seeds, despite their high abundance. These challenges pose difficulties in studying seed endophytes, making many of their effects on plants unclear. In this article, a framework for understanding the assembly and function of seed endophytes, including their sources and colonization processes was outlined in detail and available research on bacterial endophytes discovered within the seeds of various plant species has also been explored. Thus, this current review aims to provide valuable insights into the mechanism of underlying seed endophytic bacteria-host plant interactions and offers significant recommendations for utilizing the seed endophytic bacteria in sustainable agriculture as plant growth promoters and enhancers of environmental stress tolerance. [ABSTRACT FROM AUTHOR]

BACKGROUND: Peanut southern blight disease, caused by Sclerotium rolfsii, is a destructive soil‐borne fungal disease. The current control measures, which mainly employ succinate dehydrogenase inhibitors, are prone to resistance and toxicity to non‐target organisms. As a result, it is necessary to explore the potential of eco‐friendly fungicides for this disease. RESULTS: Fourteen novel phthalide compounds incorporating amino acid moieties were designed and synthesized. The in vitro activity of analog A1 [half maximal effective concentration (EC50) = 332.21 mg L−1] was slightly lower than that of polyoxin (EC50 = 284.32 mg L−1). It was observed that on the seventh day, the curative activity of A1 at a concentration of 600.00 mg L−1 was 57.75%, while the curative activity of polyoxin at a concentration of 300.00 mg L−1 was 42.55%. These results suggested that our compound exhibited in vivo activity. Peanut plants treated with A1 showed significant agronomic improvements compared to the untreated control. Several compounds in this series exhibited superior root absorption and conduction in comparison to the endothermic fungicide thifluzamide. The growth promotion and absorption‐conduction experiments demonstrated the reason for the superior in vivo activity of the target compound. Cytotoxic assays have demonstrated that this series of targeted compounds exhibit low toxicity levels toward human lo2 liver cells. CONCLUSION: Our results provide a new strategy for the design and synthesis of novel green compounds. Furthermore, the target compound A1 can serve as a lead for further development of green fungicides. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Gluconacetobacter diazotrophicus is a diazotrophic endophytic bacterium that promotes the growth and development of several plant species. However, the molecular mechanisms activated during plant response to this bacterium remain unclear. Here, we used the RNA-seq approach to understand better the effect of G. diazotrophicus PAL5 on the transcriptome of shoot and root tissues of Arabidopsis thaliana. G. diazotrophicus colonized A. thaliana roots and promoted growth, increasing leaf area and biomass. The transcriptomic analysis revealed several differentially expressed genes (DEGs) between inoculated and non-inoculated plants in the shoot and root tissues. A higher number of DEGs were up-regulated in roots compared to shoots. Genes up-regulated in both shoot and root tissues were associated with nitrogen metabolism, production of glucosinolates and flavonoids, receptor kinases, and transcription factors. In contrast, the main groups of down-regulated genes were associated with pathogenesis-related proteins and heat-shock proteins in both shoot and root tissues. Genes encoding enzymes involved in cell wall biogenesis and modification were down-regulated in shoots and up-regulated in roots. In contrast, genes associated with ROS detoxification were up-regulated in shoots and down-regulated in roots. These results highlight the fine-tuning of the transcriptional regulation of A. thaliana in response to colonization by G. diazotrophicus PAL5. [ABSTRACT FROM AUTHOR]

The effect of an inoculum composed of Amanita stranella and Suillus decipiens was evaluated on morphological features and total phenolic compounds in seedlings of Pinus pseudostrobus var. coatepecensis – a narrow endemic Mexican variety. The treatments were used: (1) A. stranella; (2) S. decipiens; (3) combined inoculum and (4) control, using a completely randomized design with 12 seedlings per treatment. The morphotype descriptions of both fungi significantly facilitate their identification in the field. The results showed significant differences in plant growth among the treatment groups. Seedlings treated with the combined treatment exhibited remarkable increases in height, surpassing the A. stranella, S. decipiens treatments, and the control group by 21.81%, 28.83%, and 59%, respectively. Moreover, the root collar diameter in the combined treatment group measured 2.53 cm, contrasting with the control group, 1.05 cm. Additionally, the shoot height/root length ratio and Dickson's index were both close to 1 in the combined treatment, suggesting a well-developed root system in relation to the above-ground part of the plant. The percentage of ectomycorrhizal root colonization showed no significant differences among the inoculated treatments. Furthermore, the combined treatment significantly increased the total phenolic content in plants (39.2 mg GAE g− 1). Therefore, the combined inoculation of P. pseudostrobus var. coatepecensis seedlings with A. stranella and S. decipiens is recommended during the nursery stage for reforestation practices. [ABSTRACT FROM AUTHOR]

Cotton is highly sensitive to potassium, and Xinjiang, China's leading cotton-producing region, faces a severe challenge due to reduced soil potassium availability. Biofertilizers, particularly potassium-solubilizing rhizobacteria (KSR), convert insoluble potassium into plant-usable forms, offering a sustainable solution for evergreen agriculture. This study isolated and characterized KSR from cotton, elucidated their potassium solubilization mechanisms, and evaluated the effects of inoculating KSR strains on cotton seedlings. Twenty-three KSR strains were isolated from cotton rhizosphere soil using modified Aleksandrov medium. Their solubilizing capacities were assessed in a liquid medium. Strain A10 exhibited the highest potassium solubilization capacity (21.8 ppm) by secreting organic acids such as lactic, citric, acetic, and succinic acid, lowering the pH and facilitating potassium release. A growth curve analysis and potassium solubilization tests of A10 under alkali stress showed its vigorous growth and maintained solubilization ability at pH 8–9, with significant inhibition at pH 10. Furthermore, 16S rRNA sequencing identified strain A10 as Pseudomonas aeruginosa. Greenhouse pot experiments showed that inoculating cotton plants with strain A10 significantly increased plant height and promoted root growth. This inoculation also enhanced dry biomass accumulation in both the aerial parts and root systems of the plants, while reducing the root–shoot ratio. These results suggest that Pseudomonas aeruginosa A10 has potential as a biofertilizer, offering a new strategy for sustainable agriculture. [ABSTRACT FROM AUTHOR]

Chitin has proven to be a valuable alternative to mineral fertilizers in growing media. We recently hypothesized that chitin might work as a biostimulant, attracting plant growth-promoting microbes to the rhizosphere. In particular, Mortierellales species increase in abundance massively with chitin application and might have a profound role in chitin-mediated plant growth promotion. We isolated four strains of this order classified as Linnemannia elongata from chitin-enriched growing medium and the lettuce rhizosphere. The isolates induced a consistent increase in shoot and root fresh weight and increased chlorophyll content of Arabidopsis thaliana in vitro, as measured by multispectral imaging. By studying the isolate's genomes, we postulated that this growth promotion was induced through auxin production, translocation of calcium to the plant, or both. The synergy between chitin and L. elongata was demonstrated by (i) the chitinase activity and chitin degradation potential of all isolates and (ii) the positive effect of chitin and L. elongata seed coating on germination of A. thaliana seeds compared with L. elongata seed coating without chitin. We conclude that chitin-related growth promotion is dependent on activation of the microbial community, with L. elongata as a key species. [Graphic: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Chitin amendment of peat substrate has been proven effective in promoting lettuce growth and increasing phenolic compounds in lettuce seedlings. However, the effect of chitin soil amendment on lettuce growth in mineral soil remains unexplored. The effect of chitin amendment of mineral soil on lettuce growth and metabolite changes was investigated for the first time in the present study in comparison with chitin-amended peat substrate. Our findings showed that chitin addition in peat substrate increased lettuce head weight by approximately 50% at harvest, whereas this increase was 30% when chitin was added to mineral soil. Targeted metabolomics analysis indicated that chitin addition affected the phenolic compounds in lettuce seedlings, but this effect varied between soil types. Moreover, untargeted metabolomics analysis suggested that using peat substrate or mineral soil had a greater influence on produced lettuce metabolites than chitin addition. Rhizobiome analysis showed that specifically Mortierellaceae family members, known for chitin degradation and plant growth promotion, significantly increased in peat substrate upon chitin treatment. In mineral soil, three bacterial genera and five fungi, including known plant-growth-promoting genera, were significantly more abundant upon chitin treatment but Mortierellaceae family members were not. We assume that the observed effects primarily stem from soil characteristics and from chitin-induced alterations in rhizobiome composition, particularly the presence of Mortierellaceae members, leading to promoted lettuce growth. Despite the variability, chitin remains an environmentally friendly alternative to synthetic fertilizers in lettuce production, but its beneficial effects are dependent on rhizobiome composition, which should be considered before chitin application. [Graphic: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Abstract Tobacco mosaic virus (TMV) is widely recognized as one of the most important plant viruses, causing significant agricultural losses in terms of both quality and yield worldwide each year. This study demonstrated the biosynthesis of copper oxide nanoparticles (CuONPs) using orange peel extract for effective control of TMV infection both in vitro and in vivo. After treatment with CuONPs (100 mg/L) for 2 h, TMV particles exhibited evident fragmentation in vitro, reducing infectivity on tobacco plants. Similarly, the application of CuONPs on Nicotiana benthamiana (N. benthamiana) positively impeded viral replication and accumulation in vivo. Interestingly, the expression of systemic resistance-related genes (PR1, PR2, ERF1, and JAZ3) in the host plant was up-regulated by CuONPs treatment, supporting that CuONPs activated plant immunity to inhibit TMV. Importantly, the application of CuONPs (100 mg/L) did not exhibit any toxic effects on tobacco and, instead, resulted in the promotion of chlorophyll content, as well as an increase in the fresh weight and dry weight of the plant when compared to the control treatment. Overall, we proposed that the appropriate concentration of CuONPs (100 mg/L) can directly break viral particles by passivating, boost plant immunity by stimulating systemic acquired resistance (SAR), and provide nutritional supplements to promote plant growth.

Abstract Soil salinity is a major environmental stressor impacting global food production. Staple crops like wheat experience significant yield losses in saline environments. Bioprospecting for beneficial microbes associated with stress-resistant plants offers a promising strategy for sustainable agriculture. We isolated two novel endophytic bacteria, Bacillus cereus (ADJ1) and Priestia aryabhattai (ADJ6), from Agave desmettiana Jacobi. Both strains displayed potent plant growth-promoting (PGP) traits, such as producing high amounts of indole-3-acetic acid (9.46, 10.00 µgml−1), ammonia (64.67, 108.97 µmol ml−1), zinc solubilization (Index of 3.33, 4.22, respectively), ACC deaminase production and biofilm formation. ADJ6 additionally showed inorganic phosphate solubilization (PSI of 2.77), atmospheric nitrogen fixation, and hydrogen cyanide production. Wheat seeds primed with these endophytes exhibited enhanced germination, improved growth profiles, and significantly increased yields in field trials. Notably, both ADJ1 and ADJ6 tolerated high salinity (up to 1.03 M) and significantly improved wheat germination and seedling growth under saline stress, acting both independently and synergistically. This study reveals promising stress-tolerance traits within endophytic bacteria from A. desmettiana. Exploiting such under-explored plant microbiomes offers a sustainable approach to developing salt-tolerant crops, mitigating the impact of climate change-induced salinization on global food security.

Tobacco mosaic virus (TMV) is widely recognized as one of the most important plant viruses, causing significant agricultural losses in terms of both quality and yield worldwide each year. This study demonstrated the biosynthesis of copper oxide nanoparticles (CuONPs) using orange peel extract for effective control of TMV infection both in vitro and in vivo. After treatment with CuONPs (100 mg/L) for 2 h, TMV particles exhibited evident fragmentation in vitro, reducing infectivity on tobacco plants. Similarly, the application of CuONPs on Nicotiana benthamiana (N. benthamiana) positively impeded viral replication and accumulation in vivo. Interestingly, the expression of systemic resistance-related genes (PR1, PR2, ERF1, and JAZ3) in the host plant was up-regulated by CuONPs treatment, supporting that CuONPs activated plant immunity to inhibit TMV. Importantly, the application of CuONPs (100 mg/L) did not exhibit any toxic effects on tobacco and, instead, resulted in the promotion of chlorophyll content, as well as an increase in the fresh weight and dry weight of the plant when compared to the control treatment. Overall, we proposed that the appropriate concentration of CuONPs (100 mg/L) can directly break viral particles by passivating, boost plant immunity by stimulating systemic acquired resistance (SAR), and provide nutritional supplements to promote plant growth. [ABSTRACT FROM AUTHOR]

The addition of ectomycorrhizal fungi (ECMF), beneficial rhizosphere microorganisms, to the soil can promote plant growth and resistance. Here, Populus davidiana × Populus bolleana tissue culture seedlings were grown for 3 months in soils inoculated with one of the species, then seedlings were assessed for mycorrhizal colonization rate and growth, physiological and root traits. Suillus luteus and Populus involutus each formed ectomycorrhizal associations with the seedlings. Seedling height, ground diameter, biomass, and leaf area were significantly greater after treatment with ECMF than in the non-inoculated controls. Treatment improved all physiological and root variables assessed (chlorophylls and carotenoids, cellulose, and soluble sugars and proteins; root length, surface area, projected area, mean diameter, volume, number of root tips). Seedlings inoculated with S. luteus outperformed those inoculated with P. involutus. [ABSTRACT FROM AUTHOR]

[Objective] The purpose of the paper was to study the diversity and growth promoting potential of culturable endophytic fungi in Neuwiedia singapureana, and provide a reference for the exploration of endophytic fungi resources in Hainan of China. (Method) The endo- phytic fungi strains of N. singapureana rooted from the Dialuoshan Nature Reserve in Hainan province were identified by culture method, combined with ITS sequencing, and the phosphorus dissolving and growth promotion ability of some fungi was tested. The endophytic fungi was co-cultured with the protocorms of D. officinale and A. rigida, to test their effects on the growth of the two orchids. (Result) By free- hand sections and microscopic observation, the fungal hypha in the cortex of root of the N. singapureana could be clearly observed. 24 OTUS were obtained, belonging to nine families and 14 genera, among which Trichoderma in Moniliaceae family had the highest isolation rate, with five genera (eg. Cylindrocarpon, Gliocephalotrichum) strains in Nectriaceae followed. Among them, five strains showed different degrees of phosphorus-decompressing ability, contaning Apiotrichum sp. (Neu242), Cylindrocarpon spp. (Neu83 and Neul54), Gliocladiopsis sp. (Neu245) and Mucor sp. (Neul23). Morover, Mucor sp. Neu123 and Apiotrichum sp. Neu242, showed significantly promoting effects on the growth of D. officinale and A. rigida seedlings. [Conclusion] There are abundant culturable fungi in the roots of N. singapureana. The endophytic fungi with potential phosphorus-soluble ability are screened from N. singapureana roots, which can provide growth-promoting strain resources for the artificial breeding of orchids, and also lay a foundation for the research on the mechanism of orchid mycorrhiza symbiotic phosphorus nutrition. [ABSTRACT FROM AUTHOR]

Introduction: This study used Bacillus amyloliquefaciens DGL1 isolated from the arid sandy land of the Qinghai-Tibetan Plateau as the research strain and investigated the effects of DGL1 on the biomass, physiology, and metabolites of Medicago sativa under different intensities of drought stress to provide a high- quality bacterial source and a theoretical basis for the research and development of biological fertilizer suitable for arid areas. Methods: The exopolysaccharides (EPS), 1-Aminocyclopropane-1-carboxylate deaminase (ACC), and phosphorus solubilizing capacity of DGL1 were determined. The effects of a DGL1 suspension on alfalfa biomass, physiological indexes, degree of peroxidation of cell membranes, and activity of antioxidant enzymes were determined after irrigating roots under drought stress. The effects on soil physicochemical properties were also evaluated, and metabolomics analysis was performed to explore the effect of DGL1 on the metabolites of alfalfa under drought stress. Results: Strain DGL1 produced extracellular polysaccharide EPS and ACC deaminase and was capable of phosphorus solubilization. Treatment with DGL1 increased the biomass of alfalfa under different degrees of drought stress, significantly increased the activities of alfalfa antioxidant enzymes Super Oxide Dismutase (SOD), Peroxidase (POD), and catalase (CAT), reduced the content of MDA and H2O2, and increased the content of quick-acting phosphorus, quick-acting potassium, ammonium nitrogen, and nitrate nitrogen in the soil, thus improving soil fertility. Through metabolomics analysis, DGL1 was shown to affect amino acid metabolic pathways, such as arginine, leucine, glutamate, and tyrosine, as well as the levels of energy-providing polysaccharides and lipids, in alfalfa under 15% PEG-6000 drought stress, enhancing alfalfa's capacity to resist drought stress. Discussion: Strain DGL1 enhances the drought suitability of alfalfa and has the potential for dryland development as a biological agent. [ABSTRACT FROM AUTHOR]

The term plant growth-promoting rhizobacteria (PGPR) refers to a root-associated bacteria that possesses several benefits for soil and the plant. The increasing demand for sustainable food production necessitates a shift towards agricultural practices that mitigate adverse environmental impacts. Excessive use of chemical fertilizers and pesticides has raised concerns, prompting a surge of interest in harnessing the potential of beneficial soil microorganisms, particularly plant growth-promoting rhizobacteria. This study explores the impact of soil inoculation with PGPR treatments on grapefruit seedlings, including a commercial strain of Bacillus velezensis, a fresh inoculum of Bacillus amyloliquefaciens, a mixture of three selected citrus endophytic Bacillus spp. isolates, inorganic fertilizers, and combinations thereof. The aim was to test their ability to enhance growth and nutrient uptake reducing the input of chemical fertilization. Results indicated that the combination of Bacillus velezensis and inorganic fertilization significantly improved soil nutrient availability and enhanced plant growth, surpassing both negative (water) and positive (inorganic fertilization) controls. Shoot and root systembiomass showed significant increases fromBacillus velezensis plus inorganic fertilization compared to other treatments. These findings provide insights into management methods that can reduce chemical inputs while promoting plant productivity. The demonstrated benefits of PGPR on grapefruit seedlings highlight a promising approach for future research and applications in sustainable citrus cultivation. [ABSTRACT FROM AUTHOR]

Entomopathogenic fungi, often acknowledged primarily for their insecticidal properties, fulfill diverse roles within ecosystems. These roles encompass endophytism, antagonism against plant diseases, promotion of the growth of plants, and inhabitation of the rhizosphere, occurring both naturally and upon artificial inoculation, as substantiated by a growing body of contemporary research. Numerous studies have highlighted the beneficial aspects of endophytic colonization. This review aims to systematically organize information concerning the direct (nutrient acquisition and production of phytohormones) and indirect (resistance induction, antibiotic and secondary metabolite production, siderophore production, and mitigation of abiotic and biotic stresses) implications of endophytic colonization. Furthermore, a thorough discussion of these mechanisms is provided. Several challenges, including isolation complexities, classification of novel strains, and the impact of terrestrial location, vegetation type, and anthropogenic reluctance to use fungal entomopathogens, have been recognized as hurdles. However, recent advancements in biotechnology within microbial research hold promising solutions to many of these challenges. Ultimately, the current constraints delineate potential future avenues for leveraging endophytic fungal entomopathogens as dual microbial control agents. [ABSTRACT FROM AUTHOR]

The focus of plant health management is shifting from synthetic chemicals to bio-agents, and endophytes are beneficial for this purpose. In the present study, we isolated eleven endophytic fungi from seven wild rice species. Independent treatment of endophytic fungi in rice showed significant improvements in plant growth, higher tillering and percent fertility, panicle number/hill and filled grain number in endophyte-inoculated plants compared to control plants. Growth promotion activities of two endophytes Curvularia lunata (NRRI EF-11) and Hypocreals sp. (NRRI EF-8) were recorded with increased rice yield. These isolates also exhibited higher plant growth promoting chemicals namely, Indole acetic acid (IAA) and Inorganic phosphate (IP) which was realised into better growth promotion in rice. The biocontrol efficacy of endophytic fungi was highest in NRRI EF-11among all isolates as indicated by inhibition of radial growth of pathogens by 76.98–77.06% and in NRRI EF-8 by 74.81–76.61%, which is due to higher production of prussic acid. Defense induction was confirmed by analyzing the expression of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) defense enzymes, where expression of CAT, POD and SOD increased by 19.44–25.86, 2.70–3.16, 11.14–12.95 Units g−1 in treated NRRI EF-11 plants and 18.39–25.84, 2.16–2.94, 10.96–12.62 Units g−1 in treated NRRI EF-8 plants, respectively. These two endophytes have the potentiality to manage crop health in a sustainable way. [ABSTRACT FROM AUTHOR]

Introduction: Bacillus amyloliquefaciens DGL1, isolated from the arid sandy areas in Dagler, Qinghai Province, China, promotes the growth of Avena sativa variety "Qing Yan 1". Methods: To elucidate the transcriptomic changes in the oat root system following interaction with DGL1 and to reveal the molecular mechanism by which DGL1 promotes oat growth, treatment and control groups of oat roots at 2, 4, 8, and 12 h after inoculation with a suspension of strain DGL1 were analyzed using Illumina high-throughput transcriptome sequencing technology. The differentially expressed genes were determined through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, and the metabolic pathways and key genes were analyzed. Results: The results showed that 7874, 13,392, 13,169, and 19,026 diffrentially expressed genes were significantly enriched in the glycolysis/gluconeogenesis pathway, amino acid metabolism, nitrogen metabolism, plant hormone signal transduction, and other related metabolic pathways in the oat roots at 2, 4, 8, and 12 h after inoculation with a DGL1 suspension. The GO and KEGG enrichment analyses revealed that the genes encoding plasma membrane ATPase, phosphoglycerate kinase gene PGK, ammonium transporter protein gene AMT, cellulose synthase gene CSLF6, and growth hormone response family gene IAA18 were significantly upregulated. Discussion: It is hypothesized that the pro-growth mechanism of strain DGL1 in oats is the result of the coordination of multiple pathways through the promotion of oat energy metabolism, phytohormone signaling, secondary metabolite synthesis, and amino acid metabolism. [ABSTRACT FROM AUTHOR]

[Display omitted] • HCSOF exhibits high levels of organic carbon and nutrient content. • HCSOF exhibits favorable adsorption properties. • HCSOF holds promise as a substitute for conventional chemical fertilizers. • HCSOF serves to enhance growth and bolster disease resistance of corn. Traditional methods of producing organic fertilizers result in significant nutrient loss and greenhouse gas emissions, making it challenging to align with sustainable development and the achievement of net-zero emissions goals. Hydrothermal cracking, as a novel clean technology for the utilization of organic waste into fertilizer, has been extensively studied and refined in laboratory settings, but its large-scale industrial evaluation remains limited. This study investigates the properties and field application of hydrothermal cracking solid organic fertilizer (HCSOF) produced at a pilot scale with an annual output of 10,000 tons. The results indicate that the organic matter content and total nutrient content (TN + P 2 O 5 + K 2 O) of HCSOF reached 50.6 % and 5.46 %, respectively, which are 20.6 % and 1.46 % higher than the standards for organic fertilizers in China. Additionally, contaminants such as pathogens and antibiotics in the product were completely eliminated. Elemental analysis and pore size distribution highlighted the unique adsorptive attributes of HCSOF, which showed significant effect in reducing soil ammonium nitrogen. Results from field trials indicate that the complete substitution of chemical fertilizers with HCSOF did not reduce corn yield, which remained at 9.03 t/ha. Particularly, compared to the exclusive use of chemical fertilizers, HCSOF treatments resulted in a 7.03 % and 4.70 % decrease in fresh corn lodging and disease incidence, respectively. Antibacterial tests further confirmed its ability to counter pathogens. This study provides robust evidence for scaling up hydrothermal cracking fertilizer production from laboratory to industrial levels. Future research should focus on multi-batch sampling and extended field experiments. [ABSTRACT FROM AUTHOR]

The pit mud in the Baijiu fermentation cellar is an abundant microbial resource that is closely related to the quality of baijiu. However, many naturally existing species might be in a viable but nonculturable (VBNC) state, posing challenges to the isolation and application of functional species. Herein, a previously isolated strain from baijiu mash, Umezawaea beigongshangensis, was found to contain the rpf gene that encodes resuscitation promotion factor (Rpf). Therefore, the gene was cloned and heterologously expressed, and the recombinant protein (Ub-Rpf 2) was purified. Ub-Rpf 2 was found to significantly promote the growth of resuscitated VBNC state Corynebacterium beijingensis and Sphingomonas beigongshangensis. To determine the resuscitation effect of Ub-Rpf 2 on real ecological samples, the protein was supplemented in pit mud for enrichment culture. Results revealed that specific families and genera were enriched in abundance upon Ub-Rpf 2 incubation, including a new family of Symbiobacteraceae and culturable Symbiobacterium genus. Furthermore, 14 species belonging to 12 genera were obtained in Ub-Rpf 2 treated samples, including a suspected novel species. This study lays a foundation for applying Rpf from U. beigongshangensis to exploit microbial resources in baijiu pit mud. [ABSTRACT FROM AUTHOR]

【Objective】Endophytic fungi represent significant microbial assets that exert a beneficial influence on plant growth. The method of inoculation plays a pivotal role in determining the growth-promoting efficacy of endophytic fungi.This study aims to investigate the impact of various inoculation methods on the growth-promoting potential of endophytic fungi, thereby offering valuable insights for the practical utilization of endophytic fungi.【Method】Four strains of endophytic fungi and Piriformospora indica of different species that could promote the growth of silage maize were screened from the endophytic fungi of desert plant roots in the early stage of the research group. Five strains of endophytic fungi were inoculated into the potted seedlings of silage maize by means of root irrigation with mycelial fragment suspension and root wrapping with mycelial mass. After 30 d, the biological characteristics of the seedlings inoculated with silage maize were determined, and the effects of different inoculation methods on the growth of silage maize were compared.【Result】The inoculation method had no significant effect on the mycelial infection rate and basal stem diameter of the five endophytic fungi in the roots of silage maize seedlings, but the other 17 traits related to the growth of silage maize were significantly affected by the inoculation method. The results of principal component analysis showed that the growth-promoting effect of the five endophytic fungi using mycelial fragment suspension root irrigation was significantly better than that of mycelial pellet root, and the difference between the two inoculation methods of P. indica and strain Tm36 was the largest. Ten traits of silage maize seedlings inoculated with P. indica and strain Tm36 were significantly different between the two inoculation methods, they were plant height, aboveground fresh weight, aboveground dry weight, average leaf area, leaf relative water content, root fresh weight, root surface area, root volume, whole plant fresh weight and whole plant dry weight. Among them, the five indexes of plant height, aboveground fresh weight, average leaf area, root fresh weight and whole plant fresh weight were the most different. The growth rate of P. indica inoculated with mycelial fragment suspension was 7.78, 3.74, 15.97, 7.93 and 5.36 times that of mycelial mass inoculation, and was 8.65 times, 4.33 times, 11.18 times, 16.58 times and 7.53 times that of inoculation strain Tm36.【Conclusion】The inoculation method significantly affects the growth-promoting effect of endophytic fungi. The inoculation method of mycelial fragment suspension root irrigation has better effect on the growth of silage maize seedlings than that of mycelial pellet root inoculation. It is recommended to use mycelial fragment suspension root irrigation method. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi (AMF) can help plants absorb more mineral nutrients after they colonize plant roots, and the mycelia harmonize the soil structure and physical and chemical properties by secreting compounds. AMF species co-evolve with their habitat's geographic conditions and hosts; this gradually causes differences in the AMF species. By using Melzer's reagent to analyze the morphology and using Illumina Miseq sequencing technology to perform the molecular identification of AMF communities among the four typical L. barbarum planting areas (Zhongning, Guyuan, Jinghe, and Dulan) investigated, the variety of L. barbarum roots and rhizosphere AMF communities was greater in the Zhongning area, and every region additionally had endemic species. The successfully amplified AMF was re-applied to the L. barbarum seedlings. We found that the total dry weight and accumulation of potassium increased significantly (p < 0.05), and the root volume and number of root branches were significantly higher in the plants that were inoculated with Paraglomus VTX00375 in the pot experiment, indicating that AMF improves root development and promotes plant growth. We have investigated AMF germplasm species in four regions, and we are committed to the development of native AMF resources. The multiplication and application of AMF will be conducive to realizing the potential role of biology in the maintenance of agroecology. [ABSTRACT FROM AUTHOR]

Extensive industrial activities and anthropogenic agricultural practices have led to substantial ammonia release to the environment. Although croplands can act as ammonia sinks, reduced crop production under high concentrations of ammonium has been documented. Alpha-ketoglutarate (AKG) is a critical carbon source, displaying pleiotropic physiological functions. The objective of the present study is to disclose the potential of AKG to enhance ammonium assimilation in poplars. It showed that AKG application substantially boosted the height, biomass, and photosynthesis activity of poplars exposed to excessive ammonium. AKG also enhanced the activities of key enzymes involved in nitrogen assimilation: glutamine synthetase (GS) and glutamate synthase (GOGAT), elevating the content of amino acids, sucrose, and the tricarboxylic acid cycle (TCA) metabolites. Furthermore, AKG positively modulated key genes tied to glucose metabolism and ATP synthesis, while suppressing ATP-depleting genes. Correspondingly, both H+-ATPase activity and ATP content increased. These findings demonstrate that exogenously applying AKG improves poplar growth under a high level of ammonium treatment. AKG might function through sufficient carbon investment, which enhances the carbon–nitrogen balance and energy stability in poplars, promoting ammonium assimilation at high doses of ammonium. Our study provides novel insight into AKG's role in improving poplar growth in response to excess ammonia exposure. [ABSTRACT FROM AUTHOR]

New technological approaches harness the potential of endophytic fungi as growth promoters, utilizing their bioactive compounds to protect against herbivores, insects, and various unfavourable abiotic stresses, including temperature, salinity, drought, and heavy metals. Zea mays (L.) is considered as a staple food source in many countries including South Africa. Endophytic fungi are natural growth promoters without causing any disease or symptoms of diseases. In the current study, nine endophytic fungi were examined for abiotic stress tolerance and were inoculated in the maize seeds prior to plantation. The construction of the phylogenetic tree was based on consensus sequences (ITS) using endophytic fungi produced three clades with four subgroups. Among the 9 endophytic fungi, only 3 fungal isolates (END 15, MHE 55, RNK 4) grew on 3% and 6% salinity PDA. Boeremia exigua was the only isolate that could withstand 6%. Fusarium solani (MHE 55) survived at low pH. Furthermore, Neurospora sp. (GG 9) and Fusarium solani (MHE 55) grew at 37 °C. Greenhouse experiments were conducted to establish the growth promoting properties. The highest plant height was observed in the treatment which was inoculated with Fusarium oxysporum (GG 8) followed by Fusarium solani (MHE 55), reaching 46 cm and 44 cm respectively. The significant enhancement in plant height, root weight, fresh weight and leaf size, demonstrate the potential use of the selected isolate as a growth promoter for maize. In contrast Chaetomium (PG 9) and Alternaria (MHE 68) displayed none to limited growth promoting properties. To the best of our knowledge, this is the first report on the potential use of F. solani isolated from South African geranium as a growth promoter. As the world is aiming at a more sustainable and eco-friendly agriculture, the use of such endophytes will contribute to better crop production and protection, hence more food availability. [ABSTRACT FROM AUTHOR]

In this research, our objective was to investigate the combined impact of microbial extracts and chemical fungicides on Northern corn leaf blight (NCLB), which is induced by Exserohilum turcicum, and the growth-promoting effect of the crude extracts was also determined. NCLB poses a serious threat to global maize production, necessitating sustainable and environmentally friendly solutions. Mycelial growth rate assays were used to assess the single or synergistic effects of microbial crude extracts and chemical fungicides, and the seed-soaking and root irrigation method was used to detect the growth-promoting effect of the crude extracts on maize seedlings. The results revealed an 84.60% inhibition rate of B. amyloliquefaciens gfj-4 against E. turcicum, and with an EC50 of 49.01 mg·L−1 for the crude extracts. Chemical fungicides demonstrated varying toxicity levels, with fludioxonil exhibiting the highest potency. The mixture of the crude extracts and pyraclostrobin at an 8:2 volume ratio displayed the highest toxicity ratio of 1.24, indicating a synergistic effect. The selected combinations exhibited strong synergistic effects. Soaking maize seeds with 80 mg·L−1 of the crude extracts followed by root irrigation with 40 mg·L−1 produced the most significant growth-promoting effect on maize seedlings. This study highlights the potential of microbial crude extracts to enhance the control of NCLB when combined with pyraclostrobin, along with its growth-promoting effects on maize seedlings. [ABSTRACT FROM AUTHOR]

An electric field, a field of electric force surrounding a charged particle, affects the growth, development, morphology, and physiological responses of plants. Previous studies have reported the effects of electric fields on plants, but further investigation is required to understand better how these fields influence plants. Thus, we aimed to explore the effects of both vertical and horizontal electric fields on the growth and physiological responses of lettuce (Lactuca sativa) in controlled environmental conditions. When treated 10-day-old lettuce seedlings with 5 kV/m of vertical or horizontal electrostatic fields for 28 days, the fresh weights of shoots and roots increased. The morphological changes in the leaves differed depending on the direction of the electric field. In addition, electric fields enhanced the uptake mineral content of the plants that is transported into different plant organs and tend to improve their transpiration rate and stomatal conductance. A vertical electric field accelerated sap flow through stems. The rate of the G1 phase of the cell cycle was highest following electric field treatments. Microscopy observations of stomatal size and epidermal cell size supported the notion that mineral uptake was enhanced by the increased transpiration rate and expanded leaf area. Our results indicate that electric fields have positive effects on lettuce growth and physiological responses and that the growth of lettuce is altered by electric fields from different directions. We propose that electric fields could be utilized as an environmental factor to maximize plant productivity and modulate plant responses. [ABSTRACT FROM AUTHOR]

Sclerotinia sclerotiorum (Lib.) de Bary is the causative agent of stem white mold disease which severely reduces major crop productivity including soybean and rapeseed worldwide. The current study aimed to explore plant growth-promoting traits and biocontrol of new isolated Bacillus subtilis BS-2301 to suppress S. sclerotiorum through various mechanisms. The results indicated that the BS-2301 exhibited strong biocontrol potential against S. sclerotiorum up to 74% both in dual culture and partition plate experiments. The BS-2301 and its crude extract significantly suppressed S. sclerotiorum growth involving excessive reactive oxygen species (ROS) production in mycelia for rapid death. Furthermore, the treated hyphae produced low oxalic acid (OA), a crucial pathogenicity factor of S. sclerotiorum. The SEM and TEM microscopy of S. sclerotiorum showed severe damage in terms of cell wall, cell membrane breakage, cytoplasm displacement, and organelles disintegration compared to control. The pathogenicity of S. sclerotiorum exposed to BS-2301 had less disease progression potential on soybean leaves in the detached leaf assay experiment. Remarkably, the strain also demonstrated broad-range antagonistic activity with 70%, and 68% inhibition rates against Phytophthora sojae and Fusarium oxysporum, respectively. Furthermore, the strain exhibits multiple plant growth-promoting and disease-prevention traits, including the production of indole-3-acetic acid (IAA), siderophores, amylases, cellulases and proteases as well as harboring calcium phosphate decomposition activity. In comparison to the control, the BS-2301 also showed great potential for enhancing soybean seedlings growth for different parameters, including shoot length 31.23%, root length 29.87%, total fresh weight 33.45%, and total dry weight 27.56%. The antioxidant enzymes like CAT, POD, SOD and APX under BS-2301 treatment were up-regulated in S. sclerotiorum infected plants along with the positive regulation of defense-related genes (PR1-2, PR10, PAL1, AOS, CHS, and PDF1.2). These findings demonstrate that the BS-2301 strain possesses a notable broad-spectrum biocontrol potential against different phytopathogens and provides new insight in suppressing S. sclerotiorum through various mechanisms. Therefore, BS-2301 will be helpful in the development of biofertilizers for sustainable agricultural practices.

This study evaluates the biocontrol efficacy of three bacterial strains (Pseudomonas fluorescens DTPF-3, Bacillus amyloliquefaciens DTBA-11, and Bacillus subtilis DTBS-5) and two fungal strains (Trichoderma harzianum Pusa-5SD and Aspergillus niger An-27) antagonists, along with their combinations at varying doses (5.0, 7.5, and 10.0 g/kg of seeds), against wheat powdery mildew. The most effective dose (10 g/kg seeds) was further analyzed for its impact on induced resistance and plant growth promotion under greenhouse conditions. The study measured defense enzyme activities, biochemical changes, and post-infection plant growth metrics. All tested microbial antagonists at 10 g/kg significantly reduced PM severity, with B. subtilis strain DTBS-5 outperforming others in reducing PM severity and achieving the highest biocontrol efficacy. It was followed by B. amyloliquefaciens strain DTBA-11 and P. fluorescens strain DTPF-3, with the fungal antagonists showing no significant effect. Wheat crops treated with B. subtilis strain DTBS-5 exhibited substantial increases in defense-related enzyme activities and biochemicals, suggesting an induced resistance mechanism. The study found a 45% increase in peroxidase (POD) activity, a 50% increase in catalase (CAT) activity, a 30% increase in phenolic content, and a 25% increase in soluble protein content in the wheat plants treated with microbial antagonists. The study highlights the effectiveness of microbial antagonists, particularly B. subtilis strain DTBS-5, in managing wheat PM through biocontrol, induced resistance, and enhanced plant growth, offering a sustainable alternative to chemical treatments.

BACKGROUND: Fusarium maize ear and root rot disease caused by Fusarium verticillioides has become one of the most serious fungal diseases associated with maize production. Due to their abilities to promote plant development and manage diseases, bacterial endophytes provide a more promising approach for treating this vascular disease. RESULTS: This work was undertaken for the selection and identification of promising isolates as plant growth promoters and biocontrol agents against F. verticillioides in maize agroecosystems. A screening procedure consisting of in vitro and in situ tests was applied to 27 endophytic strains originating from desert plants: Euphorbia antiquorum, Calotropis procera, and Alcasia albida. In vitro studies indicated that the bacteria exhibited variable results in biocontrol, endophytism, and plant growth‐promoting traits. In addition, in situ plant growth promotion and biocontrol experiments allowed the identification of the most promising bacterial endophytes. In vitro and in situ comparative study results indicated a low correlation. Our data revealed that in situ screening must be used as the method of selection of biocontrol agents against Fusarium ear and root rot disease. Based on in situ results, seven potent strains were selected and identified as Bacillus subtilis, Bacillus velezensis, Bacillus tequilensis, Stenotrophomonas maltophilia, and Klebsiella pneumoniae. CONCLUSION: The results of this study showed that the selected strains seem to be promising candidates to be exploited as biofertilizers and biocontrol agents against Fusarium maize ear and root rot disease. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Plants select microorganisms from the surrounding bulk soil, which act as a reservoir of microbial diversity and enrich a rhizosphere microbiome that helps in growth and stress alleviation. Plants use organic compounds that are released through root exudates to shape the rhizosphere microbiome. These organic compounds are of various spectrums and technically gear the interplay between plants and the microbial world. Although plants naturally produce organic compounds that influence the microbial world, numerous efforts have been made to boost the efficiency of the microbiome through the addition of organic compounds. Despite further crucial investigations, synergistic effects from organic compounds and beneficial bacteria combinations have been reported. In this review, we examine the relationship between organic compounds and beneficial bacteria in determining plant growth and biotic and abiotic stress alleviation. We investigate the molecular mechanism and biochemical responses of bacteria to organic compounds, and we discuss the plant growth modifications and stress alleviation done with the help of beneficial bacteria. We then exhibit the synergistic effects of both components to highlight future research directions to dwell on how microbial engineering and metagenomic approaches could be utilized to enhance the use of beneficial microbes and organic compounds. [ABSTRACT FROM AUTHOR]

Soil salinity is one of the major environmental stresses that results in reduction of cultivable land and decreased productivity. In the present study, halotolerant and plant growth-promoting endophytic fungi were isolated from Catharanthus roseus, and their e ect in mitigating salt stress in Vigna radiata was evaluated. An isolate CR7, identified to be Aspergillus terreus, showing plant growth promotion activities, viz. IAA production (23.43 ± 0.79 µg/ml), phosphate solubilization (133.63 ± 6.40 µg/ml), ACC deaminase activity (86.36 ± 2.70 µmol α-ketobutyrate/h/mg protein) etc. and ability to grow at 15% NaCl was selected for further in vivo studies. Colonization of CR7 was carried out in V. radiata which was subjected to di erent concentrations of salt (150, 200, and 250 mM NaCl). Under salt stress, A. terreus CR7 inoculated plants showed substantially improved root and shoot length, biomass, chlorophyll content, relative water content, phenolics, protein content, and DPPH scavenging activity. Endogenous IAA level was enhanced by 5.28-fold in treated plants at maximum salt stress. Inoculation of A. terreus CR7 a ected oxidative stress parameters, exhibiting an increase in catalase and superoxide dismutase and reduction in proline, electrolyte leakage, and malondialdehyde content. Fluorescent microscopic analysis of roots revealed improved cell viability and decreased levels of glutathione and hydrogen peroxide under salt stress in treated plants. The isolate A. terreus CR7 also protected against DNA damage induced by salt stress which was evaluated using comet assay. A decrease in DNA tail length, tail moment, and olive tail moment to the extent of 19.87%, 19.76%, and 24.81%, respectively, was observed in A. terreus CR7-colonized plants under salt stress. It can be concluded that A. terreus CR7 can be exploited for alleviating the impact of salt stress in crop plants. [ABSTRACT FROM AUTHOR]

With the continuous expansion of the scale of fish farming in China, feed additives in fish farming have been widely concerned. Chinese herbal additives are widely used in fish farming because of their natural raw materials, small toxic side effects and pollution-free advantages. By discussing the characteristics and application of Chinese herbal additives, this paper expounds the role and application prospect of Chinese herbal additives in fish culture, in order to provide guidance for the application of Chinese herbal additives in fish culture. [ABSTRACT FROM AUTHOR]

Potato black scurf, caused by Rhizoctonia solani, is a severe soil-borne disease that affects the quality and production of potatoes worldwide. In our study, we used Paenibacillus polymyxa YF and Bacillus amyloliquefaciens HT to determine the antagonistic ability of R. solani, with a particular focus on the antagonistic action of P. polymyxa YF to R. solani and its biocontrol effect on potato black scurf. In fermentation, filtrate assay, 50% filtrate of P. polymyxa YF and B. amyloliquefaciens HT inhibited the growth of R. solani by 85.55% and 82.86%, respectively. Microscopic observations showed notable morphological changes with mycelial collapse, atrophy, and deformation following treatment with the antagonistic filtrates. Moreover, cell membrane permeability results showed increased conductivity in bacteria-treated samples compared to the control. P. polymyxa YF exhibited stable colonization on potato plants and secreted various extracellular enzymes (protease, amylase, and cellulase), along with the synthetic substances with growth-promoting effects, such as siderophores and Indole-3-acetic acid (IAA). Whether it is in the excised tissue inoculation or potted experiment, the negative control showed the highest rank of disease symptoms. In the pot experiment, after YF treatment, physiological parameters showed remarkable changes in plant height, root length, stem thickness, and dry and fresh weight. Compared to blank control, the activities of the four resistant enzymes increased significantly in the P. polymyxa YF treatment group. The upregulation in the P. polymyxa YF group was 4.04, 0.54, 0.46, and 3.10 times, respectively. PCR analysis identified genes in both bacterial strains coding for antimicrobial lipopeptides, including fenB, ituC, and srfAA, which are associated with fengycin, iturin, and surfactin synthesis. These findings demonstrated that P. polymyxa YF has a prominent antagonistic effect on R. solani, suggesting its potential as an effective biological control agent for controlling potato black scurf. [ABSTRACT FROM AUTHOR]

Forest production has great relevance in the Brazilian economy, characterized by several production sectors, including the production of seedlings. With the focus on maximizing the capacity of survival, development, and adaptation of seedlings, Trichoderma is highlighted as a potentially useful genus of microorganisms for promoting growth and higher product quality. In this sense, this review aims to describe the main mechanisms of fungi action in forest seedlings' production. The different species of the genus Trichoderma have specific mechanisms of action, and the current scenario points to more advances in the number of species. The interaction process mediated by different mechanisms of action begins in the communication with plants, from the colonization process. After the interaction, chemical dialogues allow the plant to develop better because, from colonization, the forest seedlings can maximize height and increase shoot and root development. Fungi promote solubilization and availability of nutrients to seedlings, which show numerous benefits to the development. The use of beneficial microorganisms, such as fungi of the genus Trichoderma, has become a sustainable strategy to enhance seedling development, reducing the use of agrochemicals and industrial fertilizers. [ABSTRACT FROM AUTHOR]

Rhizoctonia solani, the causal agent of stem canker and black scurf disease on potato is a real threat to potato crop with up to 50% yield reduction. Current study was carried out to determine the effect of some Trichoderma isolates with different types of soil on the above diseases under laboratory and glasshouse conditions. Eight non-pathogenic strains of Trichoderma were isolated from potato roots and surrounding soil and examined for antagonism of Rhizoctonia diseases. Results showed that strains T. hamatum T8 and T. harzianum T5 had great potential as biocontrol agents for inhibiting the pathogen growth in dual culture and culture filtrate methods. The effect of different types of soils on the radial growth of R. solani AG-3PT in plates showed that Dorrigo soil inhibited the pathogen growth in laboratory by 68% as the colony diameter of pathogen recorded 2.8 cm which exceeds other soil types. While most Trichoderma strains that isolated from this area had a potential of protecting potatoes from the infection by the pathogen and acted as a biocontrol agent. Applying non-pathogenic Trichoderma isolates was the best method when inoculated the soil of pots with conidial suspensions which promote the growth of potato plants. T. harzianum (T5), T. hamatum (T6) and T. hamatum (T8) strains were eliminated stem canker and black scurf disease and improved potato plant growth in glasshouse experiment. The outcome of current study indicated the potential for utilizing Australian Trichoderma strains to reduce Rhizoctonia diseases on potato plants and increase productivity. [ABSTRACT FROM AUTHOR]

The application of rhizobacteria has gained space in agricultural production, given the demand for more sustainable systems. However, most of the results obtained are related to soil or seed application, leaving a gap in relation to the foliar application of these microorganisms. The objective of this work was to evaluate the impact of foliar application of different types of growth-promoting rhizobacteria on morphological aspects and production components of soybean. For this, the foliar application of four rhizobacteria (Serratia sp.; Bacillus subtilis; Bacillus sp.; Pseudomonas fluorescens) was used, as well as a control without inoculation. Morphological variables of growth and production components were analyzed. The yield ratio of the treatments with rhizobacteria, concerning the control was also calculated. The foliar application with different rhizobacteria in soybean did not affect the vegetative parameters of plant height, stem diameter and dry weight of the canopy. For the number of pods per plant, number of grains per plant and grain yield the use of Bacillus sp. was superior to the other treatments, providing an average increase of 27.65%, 20.32% and 28.59%, respectively. Also, the Serratia sp., Bacillus subtilis and Pseudomonas fluorescens application increased the grain yield by 8.49%, 10.73% and 5.71%, respectively. In conclusion, for the condition of the tropical region where this study was conducted, the foliar application with different growth-promoting rhizobacteria in soybean did not interfere in the vegetative development of soybean plants. In addition, considering the factors related to the increase of production in cultivated areas, all rhizobacteria have the potential to improve yield gains when applied as foliar treatment, especially the Bacillus sp. [ABSTRACT FROM AUTHOR]

This review examines using essential oils (EOs) as an alternative approach in poultry farming to clarify their beneficial roles. The discussion introduces current challenges within the poultry industry, from antibiotic resistance and environmental concerns, setting the context for natural feeding strategies. EOs are characterized by diverse bioactive compounds such as terpenes and phenolics, known as powerful alternatives due to their strong antimicrobial, antioxidant, and growth-stimulating properties. Their chemical composition and biological activities can offer insights into their mechanism of action in bird species, specifically poultry. In the context of poultry production, the review underlines how EOs enhance growth performance, support immune responses, and improve feed efficiency. Their role in modulating gut health and potentially improving product quality was discussed herein. Combining these natural substances into poultry farming can address the growing environmental concerns. In this overview, we focus on EOs as a novel and progressive option in poultry farming, aiming to harmonize 'environmental sustainability with agricultural efficiency. [ABSTRACT FROM AUTHOR]

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Endophytes are one of the symbiotic associations which can be successfully utilized to mitigate negative effects of abiotic stress in agricultural crops. Habitat adapted symbiotic fungal endophytes are known to impart heavy metal stress tolerance in host plants. Besides, endophytic fungi secrete secondary metabolites and enhance the plant's ability to tolerate stressful conditions. Therefore, this study was aimed at evaluating fungal endophytes of arsenic stress adapted plants for their arsenic tolerance potential. Present study yielded 83 arsenic tolerant fungal endophytes from the plants grown in arsenic-contaminated areas of Karnataka. These isolates were screened for arsenic tolerance at different arsenic (Sodium arsenite) concentrations (100 ppm to 2000 ppm). Among the isolates, eight endophytes (S1P1R1, S3P1S1, S3P1S3, S4P2L2, S5P1S1, S6P1S3, S8P1L4 and S10P1L1) were found efficiently enduring metal stress up to 2000 ppm with tolerance index >0.5. These isolates were further re-evaluated for arsenic tolerance in biomass assay. Significantly higher biomass was achieved in all eight endophytes at 100 PPM arsenic concentration compared to non arsenic control. However, fungal biomass relatively reduced with subsequent increase in arsenic concentration from 250 ppm to 2000 ppm. Further, these endophytes were evaluated for their ability to alleviate arsenic stress and growth promotion of rice seedlings under in vitro arsenic stress condition. Rice seedlings inoculated with fungal endophytes showed significant increase in shoot length under arsenic stress compared to control. Among eight endophytes, the isolate S3P1S1 significantly enhanced shoot and root length of rice. Therefore, data obtained in the present study revealed that the fungal endophyte, isolated from arsenic adapted plant has ability to mitigate arsenic stress and improve the rice growth under arsenic condition. [ABSTRACT FROM AUTHOR]

Fungal diseases such as root rot and leaf blight cause substantial losses in coastal pine (Pinus thunbergii Parl.) seedling production, which hinders afforestation/forest restoration programs. We isolated and identified Fusarium oxysporum and Alternaria alternata as the causal agents of root rot and needle blight diseases and investigated the biocontrol efficacy against the fungal pathogens and growth promotion of coastal pine seedlings using Bacillus velezensis CE 100. The bacterium produced the hydrolytic enzymes chitinase, β-1,3-glucanase, and protease enzymes, and the crude enzyme fraction of the biocontrol strain caused the deformation of the fungal cell wall and antagonized F. oxysporum and A. alternata, causing respective inhibition of spore germination by 91.0% and 85.9% and mycelial growth by 58.3% and 54.3%, at a concentration of 1000 µL/mL. Consequently, the bacterial treatment improved the survival rate of seedlings 1.9 times relative to the control group. The bacterium secreted indole-acetic acid (IAA) phytohormone and enhanced root growth and absorption of nutrients, which notably enhanced the biomass production of coastal pine seedlings. Therefore, these results provide evidence that B. velezensis CE 100 is an effective antifungal and growth-promoting bacterium that can facilitate the production of high-quality coastal pine seedlings for the restoration and establishment of coastal forests. [ABSTRACT FROM AUTHOR]

Root development is critical to successful establishment after seedlings are out-planted on a forest restoration site. However, the restoration of an endangered Cinnamomum kanehirae using cuttings was limited by the lack of axial roots. Dark septate endophytes (DSEs) are an important group of asexual filamentous ascomycetous fungi and could promote the performance of host plants. In the current study, we explored the effects of four DSE strains (Melnikomyces sp., Acrocalymma vagum, Wiesneriomyces sp., and Tricholomataceae sp.) on the growth of C. kanehirae cuttings under nursery conditions. The results show that four DSE isolates are able to form symbiotic relationships with C. kanehira, enhancing the seedling height, fresh weight, and chlorophyll concentrations. Notably, the Melnikomyces sp. (DB5) showed significant improvements, secreting peroxidase and indole acetic acid. To facilitate the detection of DB5 within the host roots, we developed specific primers (DB5-1F/DB5-1R). We recommend the adoption of the endophyte inoculation approach and molecular detection methods in forestry nurseries as valuable tools to enhance silvicultural practices and contribute to the conservation of C. kanehirae. [ABSTRACT FROM AUTHOR]