Biological Control Mechanisms Research Articles

The chromosome level whole genome sequence and the seconary matabolism gene cluster prediction of Fusarium meridionale, the pathogen causing maize ear rot.

Fusarium meridionale is one of the pathogens causing maize ear rot, it produce bioactive secondary metabolites may threaten humans food safty, however, the production mechanism of the secondary metabolites and their interaction with maize ear remains poorly understood. To facilitate related studies, we sequenced and assembled the genome of F. meridionale strain JX18-4. The size of F. meridionale JX18-4 genome is 37.11 Mbp, include four nuclear chromosome contigs that consists of 11920 coding genes and one mitochondrial contig. 95.64% gene synteny collinearity was found between the assembly and the reference genomes F. graminearum strain PH-1. Compared to the sequences of seconary matabolism gene clusters sequences reported previously, the stain JX18-4 was predicted potential producing 8 clusters, including nivalenol, zearalenone, aurofusarin, fusarielin, fusaristatin A, fusarin, fusarubin and butenolide. This study aims to reveal the molecular mechanism of secondary metabolites producing, and the genomic information of JX18-4 will provide resources for the study of biological control mechanisms and plant-microbe interactions.

Endophytic Fungi Volatile Organic Compounds as Crucial Biocontrol Agents Used for Controlling Fruit and Vegetable Postharvest Diseases.

Fruits and vegetables are an important part of the human diet, but during transportation and storage, microbial pathogens attack and spoil fruits and vegetables, causing huge economic losses to agriculture. Traditionally used chemical fungicides leave chemical residues, leading to environmental pollution and health risks. With the emphasis on food safety, biocontrol agents are attracting more and more attention due to their environmental friendliness. Endophytic fungi are present in plant tissues and do not cause host disease. The volatile organic compounds (VOCs) they produce are used to control postharvest diseases due to their significant antifungal activity, as well as their volatility, safety and environmental protection characteristics. This review provides the concept and characterization of endophytic fungal VOCs, concludes the types of endophytic fungi that release antifungal VOCs and their biological control mechanisms, as well as focuses on the practical applications and the challenges of applying VOCs as fumigants. Endophytic fungal VOCs can be used as emerging biocontrol resources to control postharvest diseases that affect fruits and vegetables.

Photobleaching FRET-FLIM-ICS for quaternary structure quantification on cells. Theory and simulations

The oligomerization of proteins is an important biological control mechanism and has several functions in activity and stability of enzymes, structural proteins, ion channels and transcription factors. The determination of the relevant oligomeric states in terms of geometry (spatial extent), oligomer size (monomer or dimer or oligomer) and affinity (amounts of monomer, dimer and oligomer) is a challenging biophysical problem. Förster resonance energy transfer and fluorescence fluctuation spectroscopy are powerful tools that are sensitive to proximity and oligomerization respectively. Here it is proposed to combine image-based lifetime-detected Forster resonance energy transfer with image correlation spectroscopy and photobleaching to determine distances, oligomer sizes and oligomer distributions. Simulations for simple oligomeric forms illustrate the potential to improve the discrimination between different quaternary states in the cellular milieu.

Complete Genome Sequence Analysis of Bacillus subtilis MC4-2 Strain That against Tobacco Black Shank Disease.

The MC4-2 bacterium strain was isolated and purified from the Periplaneta americana intestine as a biocontrol agent with good antagonistic effect against the pathogens of a soil-borne disease called tobacco black shank. The MC4-2 strain was found to have good broad-spectrum inhibition by plate stand-off test. Based on 16S rRNA and gyrB genes, ANI analysis, and other comparative genomics methods, it was determined that the MC4-2 strain was Bacillus subtilis. The complete genome sequence showed that the genome size was 4,076,630 bp, the average GC content was 43.78%, and the total number of CDSs was 4,207. Genomic prediction analysis revealed that a total of 145 genes were annotated by the CAZy, containing mainly GH and CE enzymes that break down carbohydrates such as glucose, chitin, starch, and alginate, and a large number of enzymes involved in glycosylation were present. A total of ten secondary metabolite clusters were predicted, six clusters of which were annotated as surfactin, bacillaene, fengycin, bacillibactin, subtilosin A, and bacilysin. The present investigation found the biological control mechanism of B. subtilis MC4-2, which provides a strong theoretical basis for the best use of this strain in biological control methods and provides a reference for the subsequent development of agents of this bacterium.

Shared phylogeographic patterns and environmental responses of co-distributed soybean pests: Insights from comparative phylogeographic studies of Riptortus pedestris and Riptortus linearis in the subtropics of East Asia

Comparative phylogeographic studies of closely related species sharing co-distribution areas can elucidate the role of shared historical factors and environmental changes in shaping their phylogeographic pattern. The bean bugs, Riptortus pedestris and Riptortus linearis, which both inhabit subtropical regions in East Asia, are recognized as highly destructive soybean pests. Many previous studies have investigated the biological characteristics, pheromones, chemicals and control mechanisms of these two pests, but few studies have explored their phylogeographic patterns and underlying factors. In this study, we generated a double-digest restriction site-associated DNA sequencing (ddRAD-seq) dataset to investigate phylogeographic patterns and construct ecological niche models (ENM) for both Riptortus species. Our findings revealed similar niche occupancies and population genetic structures between the two species, with each comprising two phylogeographic lineages (i.e., the mainland China and the Indochina Peninsula clades) that diverged approximately 0.1 and 0.3 million years ago, respectively. This divergence likely resulted from the combined effects of temperatures variation and geographical barriers in the mountainous regions of Southwest China. Further demographic history and ENM analyses suggested that both pests underwent rapid expansion prior to the Last Glacial Maximum (LGM). Furthermore, ENM predicts a northward shift of both pests into new soybean-producing regions due to global warming. Our study indicated that co-distribution soybean pests with overlapping ecological niches and similar life histories in subtropical regions of East Asia exhibit congruent phylogeographic and demographic patterns in response to shared historical biogeographic drivers.

Genome and transcriptome sequencing of Trichoderma harzianum T4, an important biocontrol fungus of Rhizoctonia solani, reveals genes related to mycoparasitism.

Trichoderma harzianum is a well-known biological control strain and a mycoparasite of Rhizoctonia solani. To explore the mechanisms of mycoparasitism, the genome and transcriptome of T. harzianum T4 were both assembled and analyzed in this study. The genome of T. harzianum T4 was assembled into 106 scaffolds, sized 41.25 Mb, and annotated with a total of 8118 predicted genes. We analyzed the transcriptome of T. harzianum T4 against R. solani in a dual culture in three culture periods: before contact (BC), during contact (C), and after contact (AC). Transcriptome sequencing identified 1092, 1222, and 2046 differentially expressed genes (DEGs), respectively. These DEGs, which are involved in pathogen recognition and signal transduction, hydrolase, transporters, antibiosis, and defense-related functional genes, are significantly upregulated in the mycoparasitism process. The results of genome and transcriptome analysis indicated that the mycoparasitism process of T. harzianum T4 was very complex. T. harzianum successfully recognizes and invades host cells and kills plant pathogens by regulating various DEGs at different culture periods. The relative expression levels of the 26 upregulated DEGs were confirmed by RT-qPCR to validate the reliability of the transcriptome data. The results provide insight into the molecular mechanisms underlying T. harzianum T4's mycoparasitic processes, and they provide a potential molecular target for the biological control mechanism of T. harzianum T4.

Microbial Interactions in the Management of Groundnut Stem Rot

Groundnut (Arachis hypogaea L.) is an important oil seed crop in the world belonging to the Leguminosae family. It is one of the essential food and cash crops of our country. In India, a large number of diseases attack groundnut [1]. Among soil borne diseases, stem rot or white mold caused by Sclerotium rolfsii Sacc. [2] is an important disease causing significant yield losses in several groundnut growing countries (Mehan et al., 1994). Sclerotium rolfsii Sacc. is a destructive soil borne fungal pathogen of oil seed crop in India. Different practices are recommended for management of groundnut stem rot such as deep summer ploughing, destruction of plant debris, crop rotation with jowar and bajra, seed treatment with carbendazim or captan or mancozeb or tebuconazole, soil drenching with hexaconazole, application of ammonium sulphate or calcium ammonium nitrate instead of urea and application of gypsum at flowering stage. Further, no single treatment is full proof and disease continues to cause losses in farmers’ fields. Biological control offers an interesting alternative to fungicides for sustainable management of soil borne diseases. Biocontrol is a non-chemical measure, could be effective as chemical control by various techniques. Among the techniques, the mixture of antagonists was studied to enchance the control efficacy. In most studies, the involvement of only mechanism of biological control is demonstrated. Involvement of more than one mechanism has been reported in only a few systems. Use of several biocontrol agents with several mechanisms of control fits in well with the concepts of integrated disease management, in which several means of disease suppression are applied concurrently. When single or more means of mechanisms are not effective, the others may compensate for the former absence. The present study, involved three major bacterial antagonists viz., Streptomyces violaceusniger, Streptomyces exfoliatus and Pseudomonas fluorescens to find out the effective dose of mixtures. The different doses from 10-1 to 10-5 were studied, the dose 10-1 of Streptomyces violaceusniger have more efficiency of 86.70, than S. exfoliatus. The efficacy of Streptomyces violaceusniger with combination of other antagonists were tested and found that, the mixture of Streptomyces violaceusniger and P. fluorescens have synergistic activity than any other combinations which have synergistic factor greater than one.

Whole-genome analysis revealed the growth-promoting and biological control mechanism of the endophytic bacterial strain Bacillus halotolerans Q2H2, with strong antagonistic activity in potato plants.

Endophytes are colonizers of healthy plants and they normally exhibit biocontrol activities, such as reducing the occurrence of plant diseases and promoting plant growth. The endophytic bacterium Bacillus halotolerans Q2H2 (Q2H2) was isolated from the roots of potato plants and was found to have an antagonistic effect on pathogenic fungi. Q2H2 was identified by morphological observations, physiological and biochemical identification, and 16S rRNA gene sequence analysis. Genes related to the anti-fungal and growth-promoting effects were analyzed using whole-genome sequencing and comparative genomic analysis. Finally, we analyzed the growth-promoting and biocontrol activities of Q2H2 in potato plants using pot experiments. Antagonism and non-volatile substance plate tests showed that Q2H2 had strong antagonism against Fusarium oxysporum, Fusarium commune, Fusarium graminearum, Fusarium brachygibbosum, Rhizoctonia solani and Stemphylium solani. The plate test showed that Q2H2 had the ability to produce proteases, cellulases, β-1,3-glucanase, dissolved organic phosphate, siderophores, indole-3-acetic acid (IAA), ammonia and fix nitrogen. The suitable growth ranges of Q2H2 under different forms of abiotic stress were pH 5-9, a temperature of 15-30°C, and a salt concentration of 1-5%. Though whole-genome sequencing, we obtained sequencing data of approximately 4.16 MB encompassed 4,102 coding sequences. We predicted 10 secondary metabolite gene clusters related to antagonism and growth promotion, including five known products surfactin, bacillaene, fengycin, bacilysin, bacillibactin, and subtilosin A. Average nucleotide identity and comparative genomic analyses revealed that Q2H2 was Bacillus halotolerans. Through gene function annotation, we analyzed genes related to antagonism and plant growth promotion in the Q2H2 genome. These included genes involved in phosphate metabolism (pstB, pstA, pstC, and pstS), nitrogen fixation (nifS, nifU, salA, and sufU), ammonia production (gudB, rocG, nasD, and nasE), siderophore production (fhuC, fhuG, fhuB, and fhuD), IAA production (trpABFCDE), biofilm formation (tasA, bslA, and bslB), and volatile compound production (alsD, ilvABCDEHKY, metH, and ispE), and genes encoding hydrolases (eglS, amyE, gmuD, ganB, sleL, and ydhD). The potato pot test showed that Q2H2 had an obvious growth-promoting effect on potato roots and better control of Fusarium wilt than carbendazim. These findings suggest that the strain-specific genes identified in bacterial endophytes may reveal important antagonistic and plant growth-promoting mechanisms.

Evaluation of Toxicity Effect of different Insecticides against Camponotus Compressus.

Carpenter ant species play a significant ecological role and are widely prevalent. Ants contribute to safeguarding plants from sap-sucking pest insects through natural biological control mechanisms. The current study was conducted to collect ants from Block B farms at Muhammad Nawaz Sharif University of Agriculture, Multan (MNSUAM), Pakistan. In current study, various insecticides (such as Imidacloprid, Fipronil, Methoxyfenozide, Emamectin benzoate, and Flubendiamide) were formulated at different concentrations (including 160, 80, 40, 20, 10, 5, and 0 ppm) for evaluation against carpenter ants. Notably, Fipronil and emamectin benzoate exhibited heightened toxicity, even at lower doses of 5 ppm and 10 ppm, resulting in the mortality of nearly all worker ants within 24 hours. In contrast, Imidacloprid displayed no distinct preference, as most worker ants remained alive even after 72 hours. These findings indicate that Fipronil and emamectin benzoate may serve as effective active ingredients for controlling carpenter ants. The data was meticulously recorded and subjected to rigorous statistical analysis using specialized software.

Biological control of potato common scab and growth promotion of potato by Bacillus velezensis Y6.

Potato common scab, caused mainly by Streptomyces scabies, causes surface necrosis and reduces the economic value of potato tubers, but effective chemical control is still lacking. In this study, an attempt was made to control potato common scab by inoculating potatoes with Bacillus velezensis (B. velezensis) and to further investigate the mechanism of biological control. The results showed that B. velezensis Y6 could reduce the disease severity of potato common scab from 49.92 ± 25.74% [inoculated with Streptomyces scabies (S. scabies) only] to 5.56 ± 1.89% (inoculated with S. scabies and Y6 on the same day) and increase the potato yield by 37.32% compared with the control under pot experiment in this study. Moreover, in the field trial, it was found that Y6 could also significantly reduce disease severity from 13.20 ± 1.00% to 4.00 ± 0.70% and increase the potato yield from 2.07 ± 0.10 ton/mu to 2.87 ± 0.28 ton/mu (p < 0.01; Tukey's test). Furthermore, RNA-seq analysis indicated that 256 potato genes were upregulated and 183 potato genes were downregulated in response to B. velezensis Y6 inoculation. In addition, strain Y6 was found to induce the expression of plant growth-related genes in potato, including cell wall organization, biogenesis, brassinosteroid biosynthesis, and plant hormone transduction genes, by 1.01-4.29 times. As well as up-regulate hydroquinone metabolism-related genes and several transcription factors (bHLH, MYB, and NAC) by 1.13-4.21 times. In summary, our study will help to understand the molecular mechanism of biological control of potato common scab and improve potato yield.

Biocontrol fungi induced stem-base rot disease resistance of Morinda officinalis How revealed by transcriptome analysis.

Morinda officinalis How (MO) is a Rubiaceae plant, and its medicinal part is dried root, which is one of the "Four Southern Medicines" in China. At present, the plant MO breed seedlings mainly by cutting methods. Long-term asexual propagation makes pathogenic fungi accumulate in MO, leading to stem-base rot, which is caused by Fusarium oxysporum (Fon). In this study, we used Trichoderma harzianum and Pestalotiopsis sp. as biocontrol fungi to investigate their antagonistic ability to Fon through in vitro antagonism and pot experiments, and combined with transcriptome sequencing to explore the mechanism of biocontrol. The results showed that both Trichoderma harzianum and Pestalotiopsis sp. could inhibit the growth of Fon. In addition, Trichoderma harzianum and Pestalotiopsis sp. could also enhance the basic immunity to Fon by increasing the activities of defensive enzymes such as POD and SOD, chlorophyll content, soluble sugar content, and oligosaccharide content of MO. The mechanism of biological control of stem-base rot of MO was discussed by transcriptome technology. MO was treated with two treatments, root irrigation with biocontrol fungi or inoculation with Fon after root irrigation with biocontrol fungi. Transcriptome sequencing revealed that nearly 11,188 differentially expressed genes (DEGs) were involved in the process of inducing MO systemic resistance to Fon by biocontrol fungi. Meanwhile, Gene Ontology (GO) classification and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, as well as transcription factor (TFs) prediction showed that there were significant differences in the expression levels of MO roots under different treatments. Also, the genes of the "MAPK signaling pathway" and "plant hormone signaling pathway" were analyzed, in which the ERFs gene of the ethylene signal transduction pathway participated in the metabolism of glycosyl compounds. It is speculated that the ethylene signal may participate in the immune response of the sugar signal to the infection of Fon. After qRT-PCR verification of 10 DEGs related to the ethylene signal transduction pathway, the expression trend is consistent with the results of transcriptome sequencing, which proves the reliability of transcriptome sequencing. In conclusion, this study preliminarily identified the molecular mechanism of the biological control of MO stem-base rot and provided a scientific basis for further research on the prevention and control mechanism of MO stem-base rot.

The Characterization of the Inhibitory Substances Produced by Bacillus pumilus LYMC-3 and the Optimization of Fermentation Conditions

Bacillus pumilus plays a very important role in the biological control of plant diseases. In this study, we conducted indoor biocontrol experiments using the LYMC-3 strain of B. pumilus to assess its efficacy against poplar canker and tea gray blight. Simultaneously, we explored the optimal fermentation conditions for the production of inhibitory substances against Phomopsis macrospora and Pestalotiopsis vesicolor. Subsequently, the inhibitory substances were extracted crudely and subjected to a preliminary investigation of their properties. The results of the indoor biocontrol experiments showed that the LYMC-3 strain exhibited disease prevention rates of 44.12% and 48.59% against poplar canker and tea gray blight, respectively. The fermentation optimization experiment showed that a culture medium containing 10 g/L of glucose, 15 g/L of tryptone, and 5 g/L of sodium chloride favored the production of inhibitory substances via the LYMC-3 strain. Among the crude extracts obtained, the non-protein extracts demonstrated the most obvious inhibitory effects. Furthermore, the inhibitory substances exhibited high polarity, excellent thermal stability, and high sensitivity to strong acids and bases. This study establishes a theoretical foundation for the purification and identification of inhibitory substances using the LYMC-3 strain. Additionally, it contributes to elucidating biological control mechanisms and facilitates the application of the LYMC-3 strain in production.

Abrupt permafrost thaw triggers activity of copiotrophs and microbiome predators.

Permafrost soils store a substantial part of the global soil carbon and nitrogen. However, global warming causes abrupt erosion and gradual thaw, which make these stocks vulnerable to microbial decomposition into greenhouse gases. Here, we investigated the microbial response to abrupt in situ permafrost thaw. We sequenced the total RNA of a 1m deep soil core consisting of up to 26'500-year-old permafrost material from an active abrupt erosion site. We analysed the microbial community in the active layer soil, the recently thawed, and the intact permafrost, and found maximum RNA: DNA ratios in recently thawed permafrost indicating a high microbial activity. In thawed permafrost, potentially copiotrophic Burkholderiales and Sphingobacteriales, but also microbiome predators dominated the community. Overall, both thaw-dependent and long-term soil properties significantly correlated with changes in community composition, as did microbiome predator abundance. Bacterial predators were dominated in shallower depths by Myxococcota, while protozoa, especially Cercozoa and Ciliophora, almost tripled in relative abundance in thawed layers. Our findings highlight the ecological importance of a diverse inter-kingdom and active microbial community highly abundant in abruptly thawing permafrost, as well as predation as potential biological control mechanism.

Potential and Prospects of Trichoderma in Plant Protection

In order to feed the growing population, agriculture is a vital component of any country; however, pests pose a constant threat to it. Chemical pesticides are employed to safeguard the crops from the enormous yield loss. These chemical pesticides are boundless in killing crop pests; however, they have detrimental effects on the health of both humans and the environment. Therefore, biological control techniques are being utilised after identifying an environmentally suitable substitute. Due to its well-known biological control mechanism, Trichoderma spp. have been utilised extensively in agricultural applications. The host plant’s soil and rhizosphere serve as shelter place for Trichoderma. It has the ability to create a variety of secondary metabolites and secretion of important enzymes. Clarification of Trichoderma’s importance in the prevention and treatment of plant diseases is thus important in order to advance sustainable agriculture. The mechanisms, which include mycoparasitism, antibiosis and competition aid in the management of insect pests and plant pathogens in the soil, seeds, roots, stems, leaves, etc. It is crucial to create new formulations of biocontrol microorganisms with a greater level of stability and survivability in order to implement biocontrol technology in the field and enhance its commercialisation.

Zn ions and Fe plaque jointly alleviate Cu toxicity in Sargassum patens C. Agardh

Excessive Cu is toxic to Sargassum patens. Understanding the biological control mechanism behind Cu uptake, including the effect of competitive behavior with other metals, such as Zn, is beneficial for expanding our knowledge of species-specific metal uptake behavior. In this study, we cultured a macroalgal species, S. patens, and exposed it to Cu and Zn to evaluate the metal uptake behavior and biological response of S. patens. Exposure to Cu and Zn under different culture conditions not only affected the uptake behavior of each metal but also influenced S. patens growth. At low concentrations, neither metal significantly affected algal growth, whereas high concentrations of Cu negatively affected the photosynthetic activity and growth rate of S. patens. The presence of Zn at equally high concentrations was observed to increase the tolerance of S. patens to Cu exposure. Fe plaque also played a role in modulating Cu exposure; its absence increased Cu accumulation and suppressed Zn accumulation, subsequently decreasing the ability of Zn to alleviate Cu toxicity, which in turn increased algal stress.

Gravity-driven membrane coupled with oxidation technology to modify the surface properties and biofilm formation: Biofouling mitigation

Biofilms caused by biological fouling play an essential role in gravity-driven membranes’ (GDMs) flux decline and rejection rate. The effects of ozone, permanganate, and ferrate (VI) in-situ pretreatment on membrane properties and biofilm formation were systematically studied. Due to the selective retention and adsorption of algal organic matter by biofilms and oxidative degradation, the rejection efficiency of dissolved organic carbon (DOC) in algae-laden water pretreated with permanganate by GDM was up to 23.63%. Pre-oxidation extraordinarily postponed flux decline and biofilm formation of GDM and reduced membrane fouling. The total membrane resistance decreased by 87.22%–90.30% within 72 h after pre-ozonation. Permanganate was more effective than ozone and ferrate (VI) in alleviating secondary membrane fouling caused by algal cells destroyed by pre-oxidation. Extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory revealed that the distribution of electrostatic force (EL), acid-base (AB), and Lifshitz-van der Waals forces (LW) interactions between M. aeruginosa and the released intracellular algogenic organic matter (IOM) and ceramic membrane surface was similar. The membrane and foulants are always attracted to each other by LW interaction at different separation distances. The dominant fouling mechanism of GDM combined with pre-oxidation technology shifts from complete pore blocking to cake layer filtration during operation. After pre-oxidation of algae-laden water by ozone, permanganate, and ferrate (VI), GDM can treat at least 131.8%, 37.0%, and 61.5% more feed solution before forming a complete cake layer. This study provides new insights into the biological fouling control strategies and mechanisms for GDM coupled with oxidation technology, which is expected to alleviate membrane fouling and optimize the feed liquid pretreatment procedure.

Virulent and attenuated strains of Trichoderma citrinoviride mediated resistance and biological control mechanism in tomato.

Root-knot nematode disease is one of the world's most serious vegetable crop diseases. In recent years, Trichoderma spp. has been widely used in root-knot nematode disease control as a biological control agent. Virulent and attenuated strains of Trichoderma citrinoviride mediated resistance and biological control mechanism in tomato were determined. Preliminary experiments found differences in nematicidal virulence among Trichoderma citrinoviride. The 24-hour corrected mortality rate of the virulent strainT1910 was as high as 92.37%, with an LC50 of 0.5585 against the second juveniles (J2s) of Meloidogyne incognita. And the attenuated strain TC9 was 23.01%, the LC50 was 2.0615, so the virulent strain T1910 had a more substantial effect on the J2s than the attenuated strain. We found that the strong virulent strain T1910 have a good control effect on M. incognita by the pot experiment of tomato than that of the attenuated virulent strain TC9,especially the J2 and J4 numbers were inhibited inside the root knots of tomato. Theinhibition rates of virulent strains reached 85.22% and 76.91%, followed by attenuatedstrain TC9, which were 63.16% and 59.17%, respectively. To reveal the differences intomato defense pathways induced by different virulent strains, qRT-PCR was further usedto detect changes in the expression of inducement-related genes. The results showed thatthe TC9 was significantly upregulated at 5dpi, LOX1, PR1, and PDF1.2. The PR5 gene ofthe virulent strain T1910 was highly upregulated, and the JA pathway was activated laterbut weaker than the attenuated strain. The results of this study revealed that thebiocontrol mechanism of T. citrinoviride as poison killing through the virulent strain T1910 and induced resistance to M. incognita through attenuated strain, although virulence degradation also has an induced resistance effect. Moreover, the attenuated strain TC9 stimulated tomato immune response earlier than the virulent strain by nematode-associated molecular pattern-triggered (NAMP). Therefore, the research elucidated the mechanism of multiple control of Trichoderma spp. against M. incognita.

Trichoderma and its role in biological control of plant fungal and nematode disease.

Trichoderma is mainly used to control soil-borne diseases as well as some leaf and panicle diseases of various plants. Trichoderma can not only prevent diseases but also promotes plant growth, improves nutrient utilization efficiency, enhances plant resistance, and improves agrochemical pollution environment. Trichoderma spp. also behaves as a safe, low-cost, effective, eco-friendly biocontrol agent for different crop species. In this study, we introduced the biological control mechanism of Trichoderma in plant fungal and nematode disease, including competition, antibiosis, antagonism, and mycoparasitism, as well as the mechanism of promoting plant growth and inducing plant systemic resistance between Trichoderma and plants, and expounded on the application and control effects of Trichoderma in the control of various plant fungal and nematode diseases. From an applicative point of view, establishing a diversified application technology for Trichoderma is an important development direction for its role in the sustainable development of agriculture.

Phenol Content and Peroxidase Enzyme Activity in Soybean Infected with Xanthomonas axonopodis pv glycines with the Application of Bacillus subtilis JB12 and Bacillus velezensis ST32

Xanthomonas axonopodis pv glycines (Xag) is a pathogen that causes pustule disease in soybeans. Many techniques for controlling this disease have been widely developed, one of which is the use of biological agents. Bacillus sp. from the soybean phyllosphere is a biological agent that has the potential to suppress the development of pustule disease. One of the biological control mechanisms is through biochemical induction of plant resistance which includes the accumulation of phenols, salicylic acid compounds, and peroxidase enzymes. Bacillus subtilis JB12 and Bacillus velezensis ST32 are two bacteria isolated from the soybean phyllosphere which have previously been known to suppress Xag through an antibiosis mechanism. This study aimed to determine the potential of Bacillus subtilis JB12 and Bacillus velezensis ST32 in inducing soybean resistance against Xag infection. This research was carried out in two stages, the induction of resistance tosoybean germination and an experiment in a greenhouse. This study consisted of 4 treatments and 5 replications, including P0 (Xag inoculation), P1 (Bacillus subtilis JB12 inoculation), P2 (Bacillus velezensisST32), and P3 (Bacillus subtilis JB12 + Bacillus velezensis ST32 inoculation). Observations were made on the content of phenolic compounds, peroxidase enzyme activity, and the development of soybean pustule disease. The results showed differences in phenol content and peroxidase activity at the two stages of the study.Seed treatment with both isolates of Bacillus sp was able to increase the phenol content of soybean sprouts up to 3 - 5 days after inoculation (dai). Phenol content then decreased and was followed by an increase in the peroxidase activity up to 7 dai. The application of Xag and two isolates of Bacillus sp. in soybean plants caused the phenol content to fluctuate and peroxidase activity to decrease. Bacillus subtilis JB12 in general played a better role in increasing phenol content and peroxidase enzyme activity in soybean than Bacillus velezensis ST32. The application of two isolates of Bacillus sp. was not able to prolong the incubation period and reduce the severity of the pustule disease 14 days after inoculation.

Coupling substrate-trapping with proximity-labeling to identify protein tyrosine phosphatase PTP1B signaling networks

The ability to define functional interactions between enzymes and their substrates is crucial for understanding biological control mechanisms; however, such methods face challenges in the transient nature and low stoichiometry of enzyme-substrate interactions. Now, we have developed an optimized strategy that couples substrate-trapping mutagenesis to proximity-labeling mass spectrometry for quantitative analysis of protein complexes involving the protein tyrosine phosphatase PTP1B. This methodology represents a significant shift from classical schemes; it is capable of being performed at near-endogenous expression levels and increasing stoichiometry of target enrichment without a requirement for stimulation of supraphysiological tyrosine phosphorylation levels or maintenance of substrate complexes during lysis and enrichment procedures. Advantages of this new approach are illustrated through application to PTP1B interaction networks in models of HER2-positive and Herceptin-resistant breast cancer. We have demonstrated that inhibitors of PTP1B significantly reduced proliferation and viability in cell-based models of acquired and de novo Herceptin resistance in HER2-positive breast cancer. Using differential analysis, comparing substrate-trapping to wild-type PTP1B, we have identified multiple unreported protein targets of PTP1B with established links to HER2-induced signaling and provided internal validation of method specificity through overlap with previously identified substrate candidates. Overall, this versatile approach can be readily integrated with evolving proximity-labeling platforms (TurboID, BioID2, etc.), and is broadly applicable across all PTP family members for the identification of conditional substrate specificities and signaling nodes in models of human disease.