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Many plant diseases are caused by phytopathogenic bacteria which greatly determine the quality of plant production. The biological control of plant pathogenic bacteria is an alternative method to the application of chemicals, which may be accomplished through the destruction of existing inoculums, exclusion from the host, or the suppression or displacement of the pathogen after infection. It offers an environmentally friendly approach to the management of plant disease and can be incorporated with cultural and physical control and limited chemical usage for an effective and integrated disease-management system. Biological control includes the use of beneficial microorganisms, such as specialized fungi and bacteria, to attack and control plant pathogens and the diseases they cause. Biological control is an innovative, cost effective and eco-friendly approach for control of many plant diseases. Bacteria of the genus Bacillus has showed antimicrobial activity against plant pathogenic microorganisms. Bacillus spp. are natural inhabitants of the phyllosphere and rhizosphere. These bacteria are involved in the control of plant diseases through a variety of mechanisms of action, such as competition, systemic resistance induction and antibiotic production. The mechanism of antibiosis has been shown to be one of the most important. Bacillus spp. have the advantage of being already adapted to the environment where they can be applied as biological control. They have the characteristics of having high thermal tolerance, showing rapid growth in liquid culture, and readily form resistant spores. It is considered safe biological agents and their potential as biocontrol agents is considered to be high. This research is based on the isolation and screening of biocontrol activities of soil Bacillus sp. against several phytopathogens in in vitro study. Since tested isolate has showed the production of antimicrobials against the growth of selected phytopathogens, in further work, all of this trial need to be supported by evaluation of antimicrobial activity in in vivo. [ABSTRACT FROM AUTHOR]

As a common disease, canker seriously affects the yield and quality of fragrant pear due to the lack of effective control measures. Some fungi have been reported to harbor rich reservoirs of viral resources, and some mycoviruses can be used as biocontrol agents against plant diseases. In this study, 199 isolates were obtained from diseased branches of fragrant pear in the main production areas of Xinjiang. Among them, 134 belonged to Valsa spp., identified using morphological and molecular biological techniques, in which V. mali was the dominant species. The mycoviruses in Valsa spp. were further identified using metatranscriptomic sequencing and RT-PCR. The results revealed that a total of seven mycoviruses were identified, belonging to Botourmiaviridae, Endornaviridae, Fusariviridae, Hypoviridae, Mitoviridae, and Narnaviridae, among which Phomopsis longicolla hypovirus (PlHV) was dominant in all the sample collection regions. The Cryphonectria hypovirus 3-XJ1 (CHV3-XJ1), Botourmiaviridae sp.-XJ1 (BVsp-XJ1), and Fusariviridae sp.-XJ1 (Fvsp-XJ1) were new mycoviruses discovered within the Valsa spp. More importantly, compared with those in the virus-free Valsa spp. strain, the growth rate and virulence of the VN-5 strain co-infected with PlHV and CHV3-XJ1 were reduced by 59% and 75%, respectively, and the growth rate and virulence of the VN-34 strain infected with PlHV were reduced by 42% and 55%, respectively. On the other hand, the horizontal transmission efficiency of PlHV decreased when PlHV was co-infected with CHV3-XJ1, indicating that PlHV and CHV3-XJ1 were antagonistic. In summary, the mycoviruses in Valsa spp. were identified in Xinjiang for the first time, and three of them were newly discovered mycoviruses, with two strains yielding good results. These results will offer potential biocontrol resources for managing pear canker disease and provide a theoretical basis for the control of fruit tree Valsa canker disease. [ABSTRACT FROM AUTHOR]

Plant diseases caused by pathogenic microorganisms in agriculture present a considerable obstacle, resulting in approximately 30–40% crop damage. The use of conventional techniques to manage these microorganisms, i.e., applying chemical pesticides and antimicrobials, has been discovered to have adverse effects on human health and the environment. Furthermore, these methods have contributed to the emergence of resistance among phytopathogens. Consequently, it has become imperative to investigate natural alternatives to address this issue. The Streptomyces genus of gram-positive bacteria is a potentially viable natural alternative that has been extensively researched due to its capacity to generate diverse antimicrobial compounds, such as metabolites and organic compounds. Scientists globally use diverse approaches and methodologies to extract new bioactive compounds from these bacteria. The efficacy of bioactive compounds in mitigating various phytopathogens that pose a significant threat to crops and plants has been demonstrated. Hence, the Streptomyces genus exhibits potential as a biological control agent for combating plant pathogens. This review article aims to provide further insight into the Streptomyces genus as a source of antimicrobial compounds that can potentially be a biological control against plant pathogens. The investigation of various bioactive compounds synthesized by this genus can enhance our comprehension of their prospective utilization in agriculture. [ABSTRACT FROM AUTHOR]

Summary: Age‐related resistance to microbe invasion is a commonly accepted concept in plant pathology. However, the impact of such age‐dependent interactive phenomena is perhaps not yet sufficiently recognized by the broader plant science community. Toward cataloging an understanding of underlying mechanisms, this review explores recent molecular studies and their relevance to the concept. Examples describe differences in genetic background, transcriptomics, hormonal balances, protein‐mediated events, and the contribution by short RNA‐controlled gene silencing events. Throughout, recent findings with viral systems are highlighted as an illustration of the complexity of the interactions. It will become apparent that instead of uncovering a unifying explanation, we unveiled only trends. Nevertheless, with a degree of confidence, we propose that the process of plant age‐related defenses is actively regulated at multiple levels. The overarching goal of this control for plants is to avoid a constitutive waste of resources, especially at crucial metabolically draining early developmental stages. [ABSTRACT FROM AUTHOR]

Many pathogens spread with sunflower seeds, which later cause plant diseases. The aim of our work was to isolate and identify sunflower seed pathogens and to investigate their effect on the germination of seeds that were formed on plants with different degrees of damage by Septoria leaf spot. Field germination of seeds was analyzed on a stationary artificial infectious background in 2020-2021, and laboratory germination and phytopathological analysis - out in laboratory conditions in 2021. All four experimental samples were found to be infected with seed infection, and the level of pathogen infection ranged from 5% to 75%. The isolated pathogens belonged to the genera Alternaria, Aspergillus, Cladosporium, Mucor, Rhizopus, Trichoderma and Penicillium. A bacterial infection was also detected. Most pathogens were found on seeds that were formed on plants affected by Septoria leaf spot. The main pathogens here were representatives of the genera Alternaria with infection from 45% to 75%, Cladosporim - 10% and bacterial infection - from 15% to 25%. The smallest number of pathogens was isolated on the seeds of healthy plants. Seed samples, both in the field and in the laboratory, differed significantly in terms of germination. It was found that the highest level of seed infection with various pathogens was characteristic of samples with low germination. The presence of the Alternaria pathogen had a negative effect on seed germination. No infection of sunflower seeds with Septoria leaf spot was detected, despite the high level of damage by this disease to the plants on which it was formed. [ABSTRACT FROM AUTHOR]

Infectious plant diseases are caused by pathogenic microorganisms, such as fungi, oomycetes, bacteria, viruses, phytoplasma, and nematodes. Plant diseases have a significant effect on the plant quality and yield and they can destroy the entire plant if they are not controlled in time. To minimize disease-related losses, it is essential to identify and control pathogens in the early stages. Plant disease control is thus a fundamental challenge both for global food security and sustainable agriculture. Conventional methods for plant diseases control have given place to electronic control (E-monitoring) due to their lack of portability, being time consuming, need for a specialized user, etc. E-monitoring using electronic nose (e-nose), biosensors, wearable sensors, and 'electronic eyes' has attracted increasing attention in recent years. Detection, identification, and quantification of pathogens based on electronic sensors (E-sensors) are both convenient and practical and may be used in combination with conventional methods. This paper discusses recent advances made in E-sensors as component parts in combination with wearable sensors, in electronic sensing systems to control and detect viruses, bacteria, pathogens and fungi. In addition, future challenges using sensors to manage plant diseases are investigated. • A comprehensive review of the application of E-sensing systems for plant disease monitoring has been undertaken. • Detection of plant infections (fungal, oomycetic, bacterial and viral) are discussed. • Recent advances in wearable sensors for plant monitoring are reviewed. • Future trends to improve e-sensing platforms are considered. [ABSTRACT FROM AUTHOR]

Background: Tobacco bacterial wilt (TBW) and black shank (TBS) are responsible for substantial economic losses worldwide; however, microbial interactions and metabolisms in response to TBW and TBS pathogens in the tobacco rhizosphere remain unclear. Methods: We explored and compared the response of rhizosphere microbial communities to these two plant diseases with the incidences in moderate and heavy degrees by sequencing of 16S rRNA gene amplicons and bioinformatics analysis. Results and discussions: We found that the structure of rhizosphere soil bacterial communities was significantly (p < 0.05) changed from the incidences of TBW and TBS, which also led to decreased Shannon diversity and Pielou evenness. Compared with the healthy group (CK), the OTUs with significantly (p < 0.05) decreased relative abundances were mostly affiliated with Actinobacteria (e.g., Streptomyces and Arthrobacter) in the diseased groups, and the OTUs with significantly (p < 0.05) increased relative abundances were mainly identified as Proteobacteria and Acidobacteria. Also, molecular ecological network analysis showed that the nodes (<467) and links (<641) were decreased in the diseased groups compared with the control group (572; 1056), suggesting that both TBW and TBS weakened bacterial interactions. In addition, the predictive functional analysis indicated that the relative abundance of genes related to the biosynthesis of antibiotics (e.g., ansamycins and streptomycin) was significantly (p < 0.05) decreased due to incidences of TBW and TBS, and antimicrobial tests showed that some Actinobacteria strains (e.g., Streptomyces) and their secreted antibiotics (e.g., streptomycin) could effectively inhibit the growth of these two pathogens. [ABSTRACT FROM AUTHOR]

Generally, advancements in various branches of science and technology have had a significant impact on various aspects of plant pathology like efficient pathogen detection. Nanotechnology is found to have many applications of which plant pathology is the one important field. In recent years, nanotechnology has been increasingly applied to the development of novel antimicrobials for the management of pathogenic bacteria affecting agricultural crops. This review discusses the applications of different nanoparticles in plant disease management and their mode of action against the bacteria. The synthesis of nanoparticles (NPs) using biomolecules (protein, enzyme, DNA and plant extracts) have opened a new avenue of research in green nanobiotechnology. They are proved to be effective, cheap and eco-friendly in combating microbes. Reactive oxygen species production, lipid peroxidation, protein oxidation, ATP depletion and DNA degradation are some of the mechanisms by which nanomaterials used to kill bacteria. [ABSTRACT FROM AUTHOR]

Background: Disease suppressiveness of soils to fungal root pathogens is typically induced in the field by repeated infections of the host plant and concomitant changes in the taxonomic composition and functional traits of the rhizosphere microbiome. Here, we studied this remarkable phenomenon for Bipolaris sorokiniana in two wheat cultivars differing in resistance to this fungal root pathogen. Results: The results showed that repeated exposure of the susceptible wheat cultivar to the pathogen led to a significant reduction in disease severity after five successive growth cycles. Surprisingly, the resistant wheat cultivar, initially included as a control, showed the opposite pattern with an increase in disease severity after repeated pathogen exposure. Amplicon analyses revealed that the bacterial families Chitinophagaceae, Anaerolineaceae and Nitrosomonadaceae were associated with disease suppressiveness in the susceptible wheat cultivar; disease suppressiveness in the resistant wheat cultivar was also associated with Chitinophagaceae and a higher abundance of Comamonadaceae. Metagenome analysis led to the selection of 604 Biosynthetic Gene Clusters (BGCs), out of a total of 2,571 identified by AntiSMASH analysis, that were overrepresented when the soil entered the disease suppressive state. These BGCs are involved in the biosynthesis of terpenes, non-ribosomal peptides, polyketides, aryl polyenes and post-translationally modified peptides. Conclusion: Combining taxonomic and functional profiling we identified key changes in the rhizosphere microbiome during disease suppression. This illustrates how the host plant relies on the rhizosphere microbiome as the first line of defense to fight soil-borne pathogens. Microbial taxa and functions identified here can be used in novel strategies to control soil-borne fungal pathogens. [ABSTRACT FROM AUTHOR]

FIFTEEN bacterial isolates were isolated from soil samples collected from Matrouh Governorate, Egypt and screened for antagonistic activity against some bacterial and fungal plant pathogens. Isolate SM3 showed the highest inhibitory effect against the tested plant pathogens. This isolate was identified using 16S rRNA encoding gene sequence analysis as Bacillus atrophaeus (GenBank accession no.: MZ741525). Its antagonistic activity was confirmed against four soft rotting bacterial isolates namely: Erwinia carotovora subsp. carotovora (Ecc) isolates: Pep7C, Cab21B2 and Cab45B and Erwinia chrysanthemi (Echr) isolate Car1B as well as four fungal plant pathogens namely: Curvularia lunata, Fusarium oxysporum, Aspergillus awamori and Penicillium sp. The antagonistic effect of B. atrophaeus SM3 on the fungal pathogens was also investigated using the mycelial reduction test where the highest mycelial reduction percentage was recorded against C. lunata (93.4%) followed by Penicillium sp. (77.8%) then F. oxysporum (61.7%) and A. awamori (41.0%).Transmission Electron Microscopy examination of the fungal isolates antagonized by B. atrophaeus SM3 showed different morphological changes including cell shrinking, alterations in the cell wall thickness, light-scattering cytoplasm, and cytoplasmic reduction. Analysis of the crude extract of B. atrophaeus SM3 by GC-mass spectroscopy indicated the presence of many compounds such as Tridecanoic acid (TDA), Pyrrole, Pentadecanoic acid and different types of fatty acids, with known biological activity for controlling pathogenic microorganisms. These results indicate that B. atrophaeus SM3 could be used as an eco-friendly biocontrol agent for successful plant disease management strategies. [ABSTRACT FROM AUTHOR]

Summary: Plant diseases are an important threat to food production. While major pathogenicity determinants required for disease have been extensively studied, less is known on how pathogens thrive during host colonization, especially at early infection stages.Here, we used randomly barcoded‐transposon insertion site sequencing (RB‐TnSeq) to perform a genome‐wide screen and identify key bacterial fitness determinants of the vascular pathogen Xanthomonas campestris pv campestris (Xcc) during infection of the cauliflower host plant (Brassica oleracea). This high‐throughput analysis was conducted in hydathodes, the natural entry site of Xcc, in xylem sap and in synthetic media.Xcc did not face a strong bottleneck during hydathode infection. In total, 181 genes important for fitness were identified in plant‐associated environments with functional enrichment in genes involved in metabolism but only few genes previously known to be involved in virulence. The biological relevance of 12 genes was independently confirmed by phenotyping single mutants. Notably, we show that XC_3388, a protein with no known function (DUF1631), plays a key role in the adaptation and virulence of Xcc possibly through c‐di‐GMP‐mediated regulation.This study revealed yet unsuspected social behaviors adopted by Xcc individuals when confined inside hydathodes at early infection stages. [ABSTRACT FROM AUTHOR]

Massoia lactone could be released from liamocins produced by Aureobasidium melanogenum M39. The obtained Massoia lactone was very stable and highly active against many fungal crop pathogens which cause many plant diseases and food unsafety. Massoia lactone treatment not only could effectively inhibit their hyphal growth and spore germination, but also caused pore formation in cell membrane, reduction of ergosterol content, rise in intracellular ROS levels, and leakage of intracellular components, consequently leading to cellular necrosis and cell death. The direct contact of Massoia lactone with Fusarium graminearum spores could stop the development of Fusarium head blight symptom in the diseased wheats. Therefore, Massoia lactone could be a promising candidate for development as an effective and green bio-fungicide because of its high anti-fungal activity and the multiplicity of mode of its action. [ABSTRACT FROM AUTHOR]

Multiple infections, either simultaneous or sequential, affecting a single plant or crop are now recognized to be common in plant disease epidemics. These multiple infections thus generate a range of competitive interactions (exploitation competition, apparent competition, or interference competition) that directly impact competitors' life history traits, and hence fitness. While a theoretical framework, based primarily on three ecological theories—niche exclusion, the "tragedy of the commons", and the virulence–transmission trade‐off, provides insights into potential outcomes of multiple infections on pathogen evolution and virulence and on disease dynamics, experimental observations, although rather rare so far, strongly suggest that unexpected outputs can also occur. This review therefore attempts to provide a comprehensive overview of both theoretical and empirical knowledge about multiple infection in plants. It highlights the need for a detailed assessment of pathogen life history traits and their modulation according to competition types, host receptivity, and pathogen life strategies for a better understanding and prediction of the evolutionary and demographic outcomes of multiple infections, as well as research questions still open in this emerging field of plant pathology. [ABSTRACT FROM AUTHOR]

Biotrophic plant pathogenic fungi are widely distributed and are among the most damaging pathogenic organisms of agriculturally important crops responsible for significant losses in quality and yield. However, the pathogenesis of obligate parasitic pathogenic microorganisms is still under investigation because they cannot reproduce and complete their life cycle on an artificial medium. The successful lifestyle of biotrophic fungal pathogens depends on their ability to secrete effector proteins to manipulate or evade plant defense response. By integrating genomics, transcriptomics, and effectoromics, insights into how the adaptation of biotrophic plant fungal pathogens adapt to their host populations can be gained. Efficient tools to decipher the precise molecular mechanisms of rust–plant interactions, and standardized routines in genomics and functional pipelines have been established and will pave the way for comparative studies. Deciphering fungal pathogenesis not only allows us to better understand how fungal pathogens infect host plants but also provides valuable information for plant diseases control, including new strategies to prevent, delay, or inhibit fungal development. Our review provides a comprehensive overview of the efforts that have been made to decipher the effector proteins of biotrophic fungal pathogens and demonstrates how rapidly research in the field of obligate biotrophy has progressed. [ABSTRACT FROM AUTHOR]

Ralstonia solanacearum is the causal agent of bacterial wilt, one of the most destructive diseases of solanaceous plants, affecting staple crops worldwide. The bacterium survives in water, soil, and other reservoirs, and is difficult to control. In this sense, the use of three specific lytic R. solanacearum bacteriophages was recently patented for bacterial wilt biocontrol in environmental water and in plants. To optimize their applications, the phages and the bacterium need to be accurately monitored and quantified, which is laborious and time-consuming with biological methods. In this work, primers and TaqMan probes were designed, and duplex and multiplex real-time quantitative PCR (qPCR) protocols were developed and optimized for the simultaneous quantification of R. solanacearum and their phages. The quantification range was established from 108 to 10 PFU/mL for the phages and from 108 to 102 CFU/mL for R. solanacearum. Additionally, the multiplex qPCR protocol was validated for the detection and quantification of the phages with a limit ranging from 102 targets/mL in water and plant extracts to 103 targets/g in soil, and the target bacterium with a limit ranging from 103 targets/mL in water and plant extracts to 104 targets/g in soil, using direct methods of sample preparation. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agriculture & Plant Sciences is the property of Goce Delcev University - Stip, Faculty of Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Clubroot is a devastating disease caused by the protist Plasmodiophora brassicaeWoronin. After root hair colonization, the clubroot pathogen induces clubs that block water uptake, leading to dehydration and death. The study of the severity of plant diseases is very important. It allows us to characterize the level of resistance of plant germplasm and to classify the virulence of pathogen strains or isolates. Lately, the use of learning machines and automatization has expanded to plant pathology. Fast, reliable and unbiased methods are always necessary, and with clubroot disease indexing this is not different. From this perspective, we discuss why this is the case and how we could achieve this long overdue task for clubroot disease. [ABSTRACT FROM AUTHOR]

Copyright of Oltenia, Studii si Comunicari Seria Stiintele Naturii is the property of Museum of Oltenia Craiova and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cucumber downy mildew (CDM) is a destructive plant disease caused by the air-borne oomycete pathogen Pseudoperonospora cubensis. CDM causes severe yield reduction of cucumber and significant economic losses. Biocontrol is a promising method to control CDM with the advantage of being beneficial to sustainable agricultural development. However, until now, no reviews of biocontrol of CDM have been reported. The objective of this review is to more comprehensively understand the biocontrol of CDM. In this review, the biological characteristics of P. cubensis are introduced, and strategies for screening biocontrol agents to suppress CDM are recommended. Then the current biocontrol agents, including fungi such as Trichoderma and biocontrol bacteria such as Bacillus, which possess the ability to control CDM, and their control characteristics and ability against CDM are also summarized. The potential mechanisms by which these biocontrol agents prevent CDM are discussed. Finally, several suggestions for future research on the biocontrol of CDM are provided. [ABSTRACT FROM AUTHOR]

Obligate fungal pathogens (ascomycetes and basidiomycetes) and oomycetes are known to cause diseases in cereal crop plants. They feed on living cells and most of them have learned to bypass the host immune machinery. This paper discusses some of the factors that are associated with pathogenicity drawing examples from ascomycetes, basidiomycetes and oomycetes, with respect to their manifestation in crop plants. The comparisons have revealed a striking similarity in the three groups suggesting convergent pathways that have arisen from three lineages independently leading to an obligate lifestyle. This review has been written with the intent, that new information on adaptation strategies of biotrophs, modifications in pathogenicity strategies and population dynamics will improve current strategies for breeding with stable resistance. [ABSTRACT FROM AUTHOR]

As the occurrence and severity of soil-borne diseases are strongly season-dependent, the ecological processes that shift plant microbiome compositions and functions upon pathogen infection in different seasons are rarely studied. In this study, we compared the differences in fungal and bacterial communities in rhizosphere soil between healthy and diseased bamboo plants throughout the four seasons at the main bamboo production site in China and investigated how basal rot disease caused by Fusarium proliferatum affected the composition, structure and ecological functions of rhizosphere-associated microorganisms. The results showed that diseased bamboo plants enriched the highest abundance of Fusarium genus in rhizosphere soil while receiving largely increased stem lesion area in summer. Microbiome analysis further proved that healthy bamboo plants harbored more ecologically beneficial microbial taxa that might function as biological protectants in their rhizosphere soil than diseased plants at the same season. Three individual strains with biocontrol potentials were further isolated and identified as Trichoderma spirale, Bacillus velezensis and Streptomyces mirabilis. The antagonistic tests further demonstrated their inhibition effects on the growth and pathogenicity of the pathogenic fungus F. proliferatum in vitro and in vivo. This study advances our understanding of soil-borne pathogen mediated changes in microbiome structure and function in plant rhizosphere soil and provides potential biocontrol strains for increasing plant resistance against basal rot disease. • The rhizosphere soil of diseased plants enriched the highest abundance of Fusarium genus in summer. • The stem lesion area of diseased plants was largely increased in summer. • Healthy plants harbored more ecologically beneficial microbes than diseased plants. • The biocontrol strains were identified as Trichoderma spirale, Bacillus velezensis and Streptomyces mirabilis. • The antagonistic effects of the strains against pathogen were tested in vitro and in vivo. [ABSTRACT FROM AUTHOR]

Septoria tritici blotch, caused by the fungal pathogen Zymoseptoria tritici, is a highly significant disease on wheat crops worldwide. The objective of the present study was to find out new bacterial strains with bio-antimicrobial activity against Z. tritici. Two phyllospheric bacteria (S1 and S6) were isolated from wheat ears and identified as Bacillus velezensis strains according to 16S rRNA Sanger sequencing. Antagonistic assays performed with either living strains or cell-free culture filtrates showed significant in vitro antifungal activities against Z. tritici. For the culture filtrates, the half-maximal inhibitory dilution and the minimal inhibitory dilution were 1.4% and 3.7% for the strain S1, and 7.4% and 15% for the strain S6, respectively. MALDI—ToF analysis revealed that both strains synthesize cyclic lipopeptides but from different families. Interestingly, only strain S1 produces putative bacillomycin D. Such differential lipopeptide production patterns might explain the difference observed between the antifungal activity of the culture filtrates of the two strains. This study allows the identification of new lipopeptide-producing strains of B. velezensis with a high potential of application for the biocontrol of Z. tritici. [ABSTRACT FROM AUTHOR]

Plant diseases are a constant and serious threat to agriculture and ecological biodiversity. Plants possess a sophisticated innate immunity system capable of detecting and responding to pathogen infection to prevent disease. Our understanding of this system has grown enormously over the past century. Early genetic descriptions of plant disease resistance and pathogen virulence were embodied in the gene-for-gene hypothesis, while physiological studies identified pathogen-derived elicitors that could trigger defense responses in plant cells and tissues. Molecular studies of these phenomena have now coalesced into an integrated model of plant immunity involving cell surface and intracellular detection of specific pathogen-derived molecules and proteins culminating in the induction of various cellular responses. Extracellular and intracellular receptors engage distinct signaling processes but converge on many similar outputs with substantial evidence now for integration of these pathways into interdependent networks controlling disease outcomes. Many of the molecular details of pathogen recognition and signaling processes are now known, providing opportunities for bioengineering to enhance plant protection from disease. Here we provide an overview of the current understanding of the main principles of plant immunity, with an emphasis on the key scientific milestones leading to these insights. Here we provide an overview of the current understanding of the main principles of plant immunity, with an emphasis on the key scientific milestones leading to these insights. [ABSTRACT FROM AUTHOR]

The alpine meadow of the Qinghai–Tibetan Plateau is an essential terrestrial ecosystem that provides a livelihood for approximately 9.8 million local inhabitants and serves as a habitat for millions of livestock. Changing facets of the global environment, such as increased nitrogen deposition, have not only affected the abundance and quality of forgeable plants but have also increased the prevalence and severity of plant diseases caused by pathogens. However, whether or not and to what extent these pathogens affect the rangeland quality of the alpine meadow remains unclear. We conducted a factorial experiment with the exclusion of fungal and oomycete pathogens to investigate the impact of various pathogens on rangeland quality in an alpine meadow in the Qinghai–Tibetan Plateau. We measured forage production for each plant species, forage quality (including measurements of organic matter, crude protein, phosphorus, total phenolics, neutral detergent fiber (NDF), metabolizable energy, and digestibility) for 11 abundant species, and community composition. We found that fungal pathogen exclusion and the combination of fungal and oomycete pathogen exclusion primarily affected nutrient production by altering forage production rather than changing community composition or forage quality. Exclusion of both fungal and oomycete pathogens led to a significant increase in community forage production, although no significant effect was observed for individual exclusion of fungal or oomycete pathogens. Excluding either fungal pathogens alone or simultaneous exclusion of both fungal and oomycete pathogens significantly increased the metabolizable energy content of the community. In contrast, oomycete pathogen exclusion significantly decreased the forage metabolizable energy content of the community. The exclusion of both fungal and oomycete pathogens also considerably increased the yield of organic matter, total phenolics, NDF, digestible dry matter, and metabolizable energy. However, the direction and magnitude of the effect of fungal and oomycete pathogen exclusion varied widely across the different species studied. These results suggest that the interaction of fungal and oomycete pathogens constitutes an essential limiting factor in rangeland quality that has not been previously recognized. Greater attention should be placed on overall forage production rather than forage quality in the context of grassland pathogen control strategies. Furthermore, metabolizable energy content may serve as an effective indicator for predicting the impact of pathogenic activity on forage quality. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the incidence of fungal plant diseases on faba beans in some fields located in the Ain–Zara region - Tripoli and to identify the causal agents. A total of one- hundred plants of faba bean were collected during 2020-2021 season from some local farms in Ain–Zara region Tripoli (February – April). Fungal pathogens associated with leaves, stems, pods and roots of faba bean have been isolated and identified. The most important and widespread fungal diseases observed: Chocolate leaf spot, Root rot, Anthracnose, Alternaria blight, Ascochyta blight and Sclerotinia stem rot caused by Botrytis fabae, Fusarium solani F. oxysporum, Colletotrichum spp, Alternaria alternata, Ascochyta fabae and Sclerotinia sp respectively. [ABSTRACT FROM AUTHOR]

Aloe barbadensis (L.) is a perennial, drought-resisting, xerophytic plant belonging to the family Liliaceae. The leaves are 40-60 cm long, erect, broad, thick and fleshy succulent, green in colour, narrow lanceolate in shape with long acuminate tip with small thorns on both edges. The central bulk of the leaf contains colourless mucilaginous pulp, made up of large, thin walled mesophyll cells. The leaf spot illness caused by Alternaria alternata is one of the fore most serious plant diseases touching business cultivation of aloe. This illness is marked by dark brown, death spots, circular to oval with grey canters developing on each surface of leaves. The experiment carried out at ANDUAT, Kumarganj Ayodhya and plant pathology laboratory in 2020-2021. The Aloe vera leaves showing symptoms of disease were collected aseptically from Medicinal & Aromatic Plant (MAP) farm, ANDUA&T, Kumarganj, Ayodhya and brought to the laboratory for isolation and identification of fungi. Pathogen was isolated from infected leaves and identified as Alternaria alternata on the basis of cultural and morphological character. The percent growth inhibition was observed in Tebuconazole @ 0.02 (100.00%) at 48 and 72 hrs followed by Bordeaux mixture (81.20%, 75.30%), Trichoderma harzianum + Pseudomonas florescence (81.09%, 73.96%), Mancozeb (79.46, 74.83%) and Nimbicidine (73.13%, 68.42%) in comparison to control, Minimum growth inhibition was recorded in Tulsi leaf extract (38.52%, 31.71%) followed by garlic bulb extract (46.13, 32.29%) and Pseudomonas florescence (68.33, 64.78%) at 48 and 72 hours. Among the systemic fungicides Tebuconazole was found best in an inhibition of spore germination and mycelial growth. It is concluded that Chemical fungicide to be more effective than botanicals and bioagents in controlling A. alternate. [ABSTRACT FROM AUTHOR]

Pathogenic microorganisms are one of the main environmental factors causing biological diseases, and their rapid spread and variety may lead to the outbreak of animal infectious diseases or plant diseases. However, the air environment is complex, the pathogen fungal infectious disease outbreak early concentration is low and the shape and size is small. There is a lack of rapid, accurate, portable and low-cost early detection methods for pathogenic fungi. Here, we construct a multispectral diffraction microfluidic sensing system for pathogenic fungi. Firstly, a microfluidic chip with the function of targeted purification of pathogenic fungi was designed, and the diffraction fingerprint of purified pathogenic fungi was collected on the chip. By analyzing the light diffraction spectrum, the morphological and absorption characteristics of different fungi at different wavelengths were obtained, and different kinds of pathogenic microorganisms in complex environment were identified. Then, seven weighting schemes were compared to select the characteristic wavelength that best reflects spore differences. Dispersion intensity compared of fingerprint (DICF) and Relative superimposed light intensity (RSLI) were defined as training indexes. To obtain higher recognition accuracy, two parameters of cluster centroid distance and dispersion are defined as evaluation indexes. Finally, 5 kinds of pathogenic fungi and particles with similar characteristics were selected for experimental verification, and the identification accuracy was 98.7%. We can foresee potential applications for this approach in disease control and environmental monitoring of airborne pathogens. • Pathogenic fungi in complex environment are low in concentration, which is difficult to capture and distinguish. • The microfluidic chip is designed to integrate separation, enrichment, detection and verification on chip. • The multi-spectral diffraction sensing system enables rapid and accurate identification of pathogenic bacteria. • It has a broad prospect in restraining the recessive spread of pathogenic microorganisms and environmental monitoring. [ABSTRACT FROM AUTHOR]

The aim of this Special Issue was to provide a platform for Spanish researchers interested in plant pathogenic microorganisms to share their recent results related to microbe-plant host interactions, microbe-vector interactions, microbe-microbe interactions, evolution, ecology, and control strategies. Pathogenic microorganisms, including fungi, oomycetes, bacteria, viruses, and viroids, constitute a serious threat to agriculture worldwide. In line with this, Spain has an important number of research groups interested in plant pathology, with scientists working on many aspects of pathogenic microorganism-plant interactions, from the basic aspects to more applied studies. In recent years, numerous important advancements have been achieved by scientists working in Spain in terms of the biological and molecular characterization of plant pathogenic microorganisms, in elucidating mechanisms of microbe pathogenesis, plant resistance to microbe infection, and plant-microbe-vector interactions. [Extracted from the article]

Pathogen adaptation to multiple selective pressures challenges our ability to control their spread. Here we analyze the evolutionary dynamics of pathogens spreading in a heterogeneous host population where selection varies periodically in space. We study both the transient dynamics taking place at the front of the epidemic and the long-term evolution far behind the front. We identify five types of epidemic profiles arising for different levels of spatial heterogeneity and different costs of adaptation. In particular, we identify the conditions where a generalist pathogen carrying multiple adaptations can outrace a coalition of specialist pathogens. We also show that finite host populations promote the spread of generalist pathogens because demographic stochasticity enhances the extinction of locally maladapted pathogens. But higher mutation rates between genotypes can rescue the coalition of specialists and speed up the spread of epidemics for intermediate levels of spatial heterogeneity. Our work provides a comprehensive analysis of the interplay between migration, local selection, mutation, and genetic drift on the spread and on the evolution of pathogens in heterogeneous environments. This work extends our fundamental understanding of the outcome of the competition between two specialists and a generalist strategy (single- vs. multiadapted pathogens). These results have practical implications for the design of more durable control strategies against multiadapted pathogens in agriculture and in public health. [ABSTRACT FROM AUTHOR]

Plants are challenged by different microbial pathogens that affect their growth and productivity. However, to defend pathogen attack, plants use diverse immune responses, such as pattern-triggered immunity (PTI), effector-triggered immunity (ETI), RNA silencing and autophagy, which are intricate and regulated by diverse signaling cascades. Pattern-recognition receptors (PRRs) and nucleotide-binding leucine-rich repeat (NLR) receptors are the hallmarks of plant innate immunity because they can detect pathogen or related immunogenic signals and trigger series of immune signaling cascades at different cellular compartments. In plants, most commonly, PRRs are receptor-like kinases (RLKs) and receptor-like proteins (RLPs) that function as a first layer of inducible defense. In this review, we provide an update on how plants sense pathogens, microbe-associated molecular patterns (PAMPs or MAMPs), and effectors as a danger signals and activate different immune responses like PTI and ETI. Further, we discuss the role RNA silencing, autophagy, and systemic acquired resistance as a versatile host defense response against pathogens. We also discuss early biochemical signaling events such as calcium (Ca2+), reactive oxygen species (ROS), and hormones that trigger the activation of different plant immune responses. This review also highlights the impact of climate-driven environmental factors on host–pathogen interactions. [ABSTRACT FROM AUTHOR]

The application and development of 'green' preventive technologies in tea plantations is an important means of ensuring tea quality and ecological safety. Ecological, agronomic and biological controls are the main preventive measures used in Guizhou Province. This paper summarizes the 'green' preventive technologies being applied in Guizhou tea plantations, including the use of plant defense inducers to regulate tea plant responses to pathogens, natural enemies to control pest species causing damage to shoots and Trifolium repens to control the main weed species. In addition, it summarizes the integrated 'green' preventive technologies being used in Guizhou and provides a foundation for the ecological maintenance of tea plantations. [ABSTRACT FROM AUTHOR]

Anthracnose, caused by Colletotrichum siamense, is a destructive disease of Pachira glabra in southern China. Early and proper monitoring and quantification of C. siamense is of importance for disease control. A calmodulin (CAL) gene-based TaqMan real-time PCR assay was developed for efficient detection and quantification of C. siamense, which reliably detected as low as 5 pg of genomic DNA and 12.8 fg (5800 copies) of target DNA. This method could specifically recognize all tested C. siamense isolates, while no amplification was observed in other closely related Colletotrichum species. The assay could still detect C. siamense in plant mixes, of which only 0.01% of the tissue was infected. A dynamic change in the amount of C. siamense population was observed during infection, suggesting that this real-time PCR assay can be used to monitor the fungal growth progression in the whole disease process. Moreover, the method enabled the detection of C. siamense in naturally infected and symptomless leaves of P. glabra trees in fields. Taken together, this specific TaqMan real-time PCR provides a rapid and accurate method for detection and quantification of C. siamense colonization in P. glabra, and will be useful for prediction of the disease to reduce the epidemic risk. [ABSTRACT FROM AUTHOR]

Rapid and reliable detection of pathogens is crucial to complement the growing industry of mass-reared insects, in order to safeguard the insect colonies from outbreak of diseases, which may cause significant economic loss. Current diagnostic methods are mainly based on conventional PCR and microscopic examination, requiring prior knowledge of disease symptoms and are limited to identifying known pathogens. Here, we present a rapid nanopore-based metagenomics approach for detecting entomopathogens from the European house cricket (Acheta domesticus). In this study, the Acheta domesticus densovirus (AdDV) was detected from diseased individuals using solely Nanopore sequencing. Virus reads and genome assemblies were obtained within twenty-four hours after sequencing. Subsequently, due to the length of the Nanopore reads, it was possible to reconstruct significantly large parts or even the entire AdDV genome to conduct studies for genotype identification. Variant analysis indicated the presence of three AdDV genotypes within the same house cricket population, with association to the vital status of the diseased crickets. This contrast provided compelling evidence for the existence of non-lethal AdDV genotypes. These findings demonstrated nanopore-based metagenomics sequencing as a powerful addition to the diagnostic tool kit for routine pathogen surveillance and diagnosis in the insect rearing industry. [ABSTRACT FROM AUTHOR]

Alternaria leaf blight has recently been described as an emerging fungal disease of apple trees which is causing the significant damage in the apple-growing areas of Tianshui and Jingning, Gansu, China. In the present study, the pathogen species involved in apple leaf blight and its biological characteristics were identified, and the inhibitory activity of different botanical fungicides against the pathogen was evaluated in vitro. Four strains were isolated from the symptomatic areas of necrotic apple leaves, and initially healthy leaves showed similar symptoms to those observed in orchards after inoculation with the ABL2 isolate. The ABL2 isolate was identified as Alternaria tenuissima based on the morphological characteristics of its colonies, conidiophores, and conidia, and this was also confirmed by multi-gene sequence (ITS, OPA10-2, Alta-1, and endoPG) analysis and phylogenic analysis. The optimum temperature, pH, carbon source, and nitrogen source for the growth of A. tenuissima mycelia were 28 °C, 6–7, soluble starch, and soy flour, respectively. In addition, the botanical fungicide eugenol exhibited the highest inhibitory effect on the mycelial growth and conidia germination of A. tenuissima, and the median effective concentration (EC50) values were 0.826 and 0.755 μg/mL, respectively. The protective and curative efficacy of eugenol were 86.85% and 76.94% after inoculation in detached apple leaves at a concentration of 4 μg/mL. Our research provides new insights into the control of apple leaf blight disease by applying botanical fungicides. [ABSTRACT FROM AUTHOR]

Mutations allowing pathogens to escape host immunity promote the spread of infectious diseases in heterogeneous host populations and can lead to major epidemics. Understanding the conditions that slow down this evolution is key for the development of durable control strategies against pathogens. Here, we use theory and experiments to compare the efficacy of three strategies for the deployment of resistance: (i) a mixing strategy where the host population contains two single-resistant genotypes, (ii) a pyramiding strategy where the host carries a double-resistant genotype, (iii) a combining strategy where the host population is a mix of a single-resistant genotype and a double-resistant genotype. First, we use evolutionary epidemiology theory to clarify the interplay between demographic stochasticity and evolutionary dynamics to show that the pyramiding strategy always yields lower probability of evolutionary emergence. Second, we test experimentally these predictions with the introduction of bacteriophages into bacterial populations where we manipulated the diversity and the depth of immunity using a Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR associated (CRISPR-Cas) system. These biological assays confirm that pyramiding multiple defences into the same host genotype and avoiding combination with single-defence genotypes is a robust way to reduce pathogen evolutionary emergence. The experimental validation of these theoretical recommendations has practical implications in various areas, including for the optimal deployment of resistance varieties in agriculture and for the design of durable vaccination strategies. [ABSTRACT FROM AUTHOR]

Anthracnose of pepper is a significant disease caused by Colletotrichum spp. In 2017 and 2021, 296 isolates were obtained from 69 disease samples. Through morphological analysis, pathogenicity detection, and polygenic phylogenetic analysis, the above strains were attributed to 10 species: C. scovillei, C. fructicola, C. karstii, C. truncatum, C. gloeosporioides, C. kahawae, C. boninense, C. nymphaeae, C. plurivorum, and C. nigrum. C. scovillei had the most strains (150), accounting for 51.02% of the total isolates; C. fructicola came in second (72 isolates), accounting for 24.49%. Regarding regional distribution, Zunyi City has the highest concentration of strains—92 strains total, or 34.18%—across seven species. Notably, this investigation showed that C. nymphaeae infected pepper fruit for the first time in China. Genetic diversity analysis showed that C. fructicola could be divided into seven haplotypes, and the population in each region had apparent genetic differentiation. However, the genetic distance between each population was not significantly related to geographical distance. Neutral detection and nucleotide mismatch analysis showed that C. fructicola might have undergone population expansion. [ABSTRACT FROM AUTHOR]

The application of biostimulants has been proven to be an advantageous tool and an appropriate form of management towards the effective use of natural resources, food security, and the beneficial effects on plant growth and yield. Plant-growth-promoting rhizobacteria (PGPR) are microbes connected with plant roots that can increase plant growth by different methods such as producing plant hormones and molecules to improve plant growth or providing increased mineral nutrition. They can colonize all ecological niches of roots to all stages of crop development, and they can affect plant growth and development directly by modulating plant hormone levels and enhancing nutrient acquisition such as of potassium, phosphorus, nitrogen, and essential minerals, or indirectly via reducing the inhibitory impacts of different pathogens in the forms of biocontrol parameters. Many plant-associated species such as Pseudomonas, Acinetobacter, Streptomyces, Serratia, Arthrobacter, and Rhodococcus can increase plant growth by improving plant disease resistance, synthesizing growth-stimulating plant hormones, and suppressing pathogenic microorganisms. The application of biostimulants is both an environmentally friendly practice and a promising method that can enhance the sustainability of horticultural and agricultural production systems as well as promote the quantity and quality of foods. They can also reduce the global dependence on hazardous agricultural chemicals. Science Direct, Google Scholar, Springer Link, CAB Direct, Scopus, Springer Link, Taylor and Francis, Web of Science, and Wiley Online Library were checked, and the search was conducted on all manuscript sections in accordance with the terms Acinetobacter, Arthrobacter, Enterobacter, Ochrobactrum, Pseudomonas, Rhodococcus, Serratia, Streptomyces, Biostimulants, Plant growth promoting rhizobactera, and Stenotrophomonas. The aim of this manuscript is to survey the effects of plant-growth-promoting rhizobacteria by presenting case studies and successful paradigms in various agricultural and horticultural crops. [ABSTRACT FROM AUTHOR]

Definition: The development of new techniques for the control of pathogenic microorganisms during food production and for the prevention of spoilage are needed to reduce or replace chemical preservatives. This is due to the trend that consumers are increasingly questioning the use of chemical preservatives because of the many health concerns. Because of this issue, bacteriocins and bacteriophages are increasingly viewed as safe natural preservatives with a long history of various applications during food production and preservation. This minireview considers applications of these two antimicrobials, highlights their mode of action, lists their advantages and, when necessary, their limitations. It also reports recent advances in the use of bacteriophages and bacteriocins either alone or in combination in different food matrices. The incentives and effectiveness offered by these antimicrobials in the field of biopreservation are considered for future applications during food production and preservation. [ABSTRACT FROM AUTHOR]

In recent years, the adoption of sustainable pest management strategies has increased interest in the utilization of biopesticides, with a focus on harnessing beneficial microorganisms. Among these, lipopeptides, such as surfactins, iturins, and fengycins produced by the genus Bacillus, have gained significant attention due to their multifaceted biocontrol mechanisms and wide-ranging inhibitory effects. This review aims to address the regulation, biosynthesis, and production of three main lipopeptide families secreted by the genus Bacillus, as well as the identification and quantification analysis used to date, through the omic tools approach. The three families have been identified as key contributors to the biocontrol abilities of these bacteria, with their broad-spectrum activity making them valuable tools in integrated pest management approaches that aim to reduce reliance on chemical pesticides use while maintaining crop health and productivity. [ABSTRACT FROM AUTHOR]

Fungal pathogenicity to plants, animals, and humans leads to several detrimental effects in our society by causing diseases that impact livelihood and food security. While the recent pandemic shifted focus to viral pathogens, fungal pathogens are still impacting the world that we live in. It is important to study fungal pathogenicity with the latest scientific advancement. One way to do that is to understand the conservation of pathogenicity in the fungus kingdom which will further elucidate the underlying mechanisms behind fungal pathogenicity across all species of fungi. This review provides an outlook on the various bioinformatics and genomics approaches and currently available resources in understanding fungal pathogenicity. It also discusses the current state of affairs and emerging trends in the study of fungal pathogenicity. Finally, this review also provide suggestions different approaches for the study of fungal pathogenicity to see further improve our understanding in this field. [ABSTRACT FROM AUTHOR]

In flowering plants, after being released from pollen grains, the male gametes use the style channel to migrate towards the ovary where they fertilize awaiting eggs. Environmental pathogens exploit the style passage, resulting in diseased progeny seed. The belief is that pollen also transmits pathogens into the style. By contrast, we hypothesized that pollen carries beneficial microbes that suppress environmental pathogens on the style passage. No prior studies have reported pollen-associated bacterial functions in any plant species. Here, bacteria were cultured from maize (corn) pollen encompassing wild ancestors and farmer-selected landraces from across the Americas, grown in a common field in Canada for one season. In total, 298 bacterial isolates were cultured, spanning 45 genera, 103 species, and 88 OTUs, dominated by Pantoea, Bacillus, Pseudomonas, Erwinia, and Microbacterium. Fulllength 16S DNA-based taxonomic profiling showed that 78% of bacterial taxa from the major wild ancestor of maize (Parviglumis teosinte) were present in at least one cultivated landrace. The species names of the bacterial isolates were used to search the pathogen literature systematically; this preliminary evidence predicted that the vast majority of the pollen-associated bacteria analyzed are not maize pathogens. The pollen-associated bacteria were tested in vitro against a style-invading Fusarium pathogen shown to cause Gibberella ear rot (GER): 14 isolates inhibited this pathogen. Genome mining showed that all the anti-Fusarium bacterial species encode phzF, associated with biosynthesis of the natural fungicide, phenazine. To mimic the male gamete migration route, three pollen-associated bacterial strains were sprayed onto styles (silks), followed by Fusarium inoculation; these bacteria reduced GER symptoms and mycotoxin accumulation in progeny seed. Confocal microscopy was used to search for direct evidence that pollen-associated bacteria can defend living silks against Fusarium graminearum (Fg); bacterial strain AS541 (Kluyvera intermedia), isolated from pollen of ancestral Parviglumis, was observed to colonize the susceptible style/silk entry points of Fg (silk epidermis, trichomes, wounds). Furthermore, on style/silk tissue, AS541 colonized/aggregated on Fg hyphae, and was associated with Fg hyphal breaks. These results suggest that pollen has the potential to carry bacteria that can defend the style/silk passage against an environmental pathogen -- a novel observation. [ABSTRACT FROM AUTHOR]

Root rot pathogens restrict pea and wheat production globally. In the EU, pea and pea-based cereal mixtures are being promoted; however, root rot pathogen dynamics in such mixtures are poorly understood. Winter pea and wheat were grown either in pure stands or in mixtures in the field in western France, and the severity of root rot in pea, wheat, and their mixtures, as well as the key pathogens associated with these crops, were assessed. Disease severity was moderate in pea and low in wheat, with no effect of sowing pattern. Didymella pinodella, a previously unreported pathogen in the pea–root rot complex in France, emerged as the most dominant pathogen in pea. It also occurred in low frequencies in wheat. Subsequent greenhouse aggressiveness tests showed that ten of the commonly grown pea cultivars in France lack resistance to D. pinodella. Among the Fusarium spp. isolated, F. avenaceum was the most frequent, occurring at similar frequencies in pea and wheat. In conclusion, D. pinodella may be an important pea root rot pathogen in France and there is a lack of resistance in the tested pea cultivars. In addition, F. avenaceum is a shared pathogen of wheat and pea. [ABSTRACT FROM AUTHOR]