scholarly journals Type 2 Nep1-Like Proteins from the Biocontrol Oomycete Pythium oligandrum Suppress Phytophthora capsici Infection in Solanaceous Plants

2021 ◽  
Vol 7 (7) ◽  
pp. 496
Author(s):  
Kun Yang ◽  
Xiaohua Dong ◽  
Jialu Li ◽  
Yi Wang ◽  
Yang Cheng ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Plant Immunity ◽  
Phytophthora Capsici ◽  
Control Plant ◽  
Plant Diseases ◽  
In Planta ◽  
Pythium Oligandrum ◽  
Suppression Effect ◽  
Peptide Pattern ◽  
Solanaceous Plants

As a non-pathogenic oomycete, the biocontrol agent Pythium oligandrum is able to control plant diseases through direct mycoparasite activity and boosting plant immune responses. Several P. oligandrum elicitors have been found to activate plant immunity as microbe-associated molecular patterns (MAMPs). Necrosis- and ethylene-inducing peptide 1 (Nep1)-like proteins (NLPs) are a group of MAMPs widely distributed in eukaryotic and prokaryotic plant pathogens. However, little is known about their distribution and functions in P. oligandrum and its sister species Pythium periplocum. Here, we identified a total of 25 NLPs from P. oligandrum (PyolNLPs) and P. periplocum (PypeNLPs). Meanwhile, we found that PyolNLPs/PypeNLPs genes cluster in two chromosomal segments, and our analysis suggests that they expand by duplication and share a common origin totally different from that of pathogenic oomycetes. Nine PyolNLPs/PypeNLPs induced necrosis in Nicotiana benthamiana by agroinfiltration. Eight partially purified PyolNLPs/PypeNLPs were tested for their potential biocontrol activity. PyolNLP5 and PyolNLP7 showed necrosis-inducing activity in N. benthamiana via direct protein infiltration. At sufficient concentrations, they both significantly reduced disease severity and suppressed the in planta growth of Phytophthora capsici in solanaceous plants including N. benthamiana (tobacco), Solanum lycopersicum (tomato) and Capsicum annuum (pepper). Our assays suggest that the Phytophthora suppression effect of PyolNLP5 and PyolNLP7 is irrelevant to reactive oxygen species (ROS) accumulation. Instead, they induce the expression of antimicrobial plant defensin genes, and the induction depends on their conserved nlp24-like peptide pattern. This work demonstrates the biocontrol role of two P. oligandrum NLPs for solanaceous plants, which uncovers a novel approach of utilizing NLPs to develop bioactive formulae for oomycete pathogen control with no ROS-caused injury to plants.

scholarly journals The Role of the Xylem in Oxytetracycline Translocation within Citrus Trees

Antibiotics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 691
Author(s):  
Faraj Hijaz ◽  
Yasser Nehela ◽  
Fuad Al-Rimawi ◽  
Christopher I. Vincent ◽  
Nabil Killiny
Keyword(s):  
Plant Pathogens ◽  
Control Plant ◽  
Plant Diseases ◽  
In Planta ◽  
Citrus Industry ◽  
Elisa Kit ◽  
Therapeutic Value ◽  
Trunk Injection ◽  
Citrus Trees

Antibiotics have been successfully used to control plant diseases for more than fifty years. Recently, oxytetracycline and streptomycin have been approved for the treatment of Huanglongbing, which is threatening the citrus industry in many regions. Because the efficiency of antibiotics in planta is highly affected by their movement and distribution, understanding the mechanism of antibiotics’ uptake and distribution could lead to a better control of plant pathogens. Herein, we investigated the movement of oxytetracycline within citrus plants. Oxytetracycline was applied by root drenching to both girdled and non-girdled citrus seedlings. In addition, oxytetracycline was applied by trunk injection to girdled and non-girdled citrus trees. After the exposure time (24 h), citrus seedlings were dissected and the levels of oxytetracycline in the different tissues were measured using an oxytetracycline ELISA kit. Upon root application (laboratory experiment), oxytetracycline was detected in the inner part of the stem (xylem-associated tissue), cortex (phloem-associated tissue), and leaves above and below the girdled area. Likewise, oxytetracycline was also detected in leaves of trunk-injected field trees (girdled and non-girdled) three days post treatment. Interestingly, cortex girdling did not affect the distribution and translocation of oxytetracycline, indicating that the xylem is the main path for oxytetracycline translocation. Taken together, our results indicate that oxytetracycline translocation mainly occurs via xylem vessels, and that movement into the phloem occurs subsequent to xylem translocation. Our findings also clearly demonstrated that upon trunk injection, only trace levels of oxytetracycline reached the roots, minimizing its therapeutic value there. Thus, our recommendation is to time tree injections to coincide with the flushing periods when the bacteria are moving into new shoots to maximize the efficiency of oxytetracycline.

scholarly journals In planta bacterial multi-omics analysis illuminates regulatory principles underlying plant-pathogen interactions

2019 ◽  
Author(s):  
Tatsuya Nobori ◽  
Yiming Wang ◽  
Jingni Wu ◽  
Sara Christina Stolze ◽  
Yayoi Tsuda ◽  
...  
Keyword(s):  
Gene Regulation ◽  
Pseudomonas Syringae ◽  
Protein Level ◽  
Plant Pathogens ◽  
Plant Immunity ◽  
Bacterial Pathogen ◽  
Bacterial Virulence ◽  
In Planta ◽  
Bacterial Gene ◽  
Global Food Security

AbstractUnderstanding how gene expression is regulated in plant pathogens is crucial for pest control and thus global food security. An integrated understanding of bacterial gene regulation in the host is dependent on multi-omic datasets, but these are largely lacking. Here, we simultaneously characterized the transcriptome and proteome of a foliar bacterial pathogen, Pseudomonas syringae, in Arabidopsis thaliana and identified a number of bacterial processes influenced by plant immunity at the mRNA and the protein level. We found instances of both concordant and discordant regulation of bacterial mRNAs and proteins. Notably, the tip component of bacterial type III secretion system was selectively suppressed by the plant salicylic acid pathway at the protein level, suggesting protein-level targeting of the bacterial virulence system by plant immunity. Furthermore, gene co-expression analysis illuminated previously unknown gene regulatory modules underlying bacterial virulence and their regulatory hierarchy. Collectively, the integrated in planta bacterial omics approach provides molecular insights into multiple layers of bacterial gene regulation that contribute to bacterial growth in planta and elucidate the role of plant immunity in controlling pathogens.

scholarly journals Actinomycetes, promising tools to control plant diseases and to promote plant growth

2005 ◽  
Vol 82 (3) ◽  
pp. 85-102 ◽  
Author(s):  
C.L. Doumbou ◽  
M.K. Hamby Salove ◽  
D.L. Crawford ◽  
C. Beaulieu
Keyword(s):  
Plant Growth ◽  
Plant Pathogens ◽  
Soil Microbial Biomass ◽  
Extracellular Enzymes ◽  
Control Plant ◽  
Plant Diseases ◽  
Soil Microbial ◽  
Plant Growth Promoting ◽  
Promote Plant Growth ◽  
Growth Promoting

Actinomycetes represent a high proportion of the soil microbial biomass and have the capacity to produce a wide variety of antibiotics and of extracellular enzymes. Several strains of actinomycetes have been found to protect plants against plant diseases. This review focuses on the potential of actinomycetes as (a) source of agroactive compounds, (b) plant growth promoting organisms, and (c) biocontrol tools of plant diseases. This review also addresses examples of biological control of fungal and bacterial plant pathogens by actinomycetes species which have already reached the market or are likely to be exploited commercially within the next few years.

Morphological and molecular based identification of Antifungal bacillus licheniformis

2017 ◽  
Vol 17 (1) ◽  
pp. 31-35
Author(s):  
B Oyuntogtokh ◽  
M Byambasuren
Keyword(s):  
Bacillus Licheniformis ◽  
Fungal Pathogens ◽  
Crop Production ◽  
Plant Pathogens ◽  
Control Plant ◽  
Plant Diseases ◽  
Bacillus Species ◽  
Bacterial Strains ◽  
Fusarium Spp ◽  
Bacterial Cultures

At present, plant diseases caused by soil borne plant pathogens have major constraints on crop production. Which include genera Fusarium spp, Phytophtora spp, Sclerotinia and Altenaria. Due to this reason, chemical fungicides are routinely used to control plant disease, which is also true in Mongolian case. However, use of these chemicals has caused various problems including environmental pollution with consequence of toxicity to human health also resistance of some pathogens to these fungicides are present. Fortunately, an alternative method to reduce the effect of these plant pathogens is the use of antagonist microorganisms. Therefore, some species of the genus Bacillus are recognized as one of the most effective biological control agent.Our research was focused to isolate Bacillus licheniformis, with antifungal potential, from indigenous sources. In the current study, 28 bacterial cultures were isolated from soil and fermented mare’s milk also named as koumiss. Isolated bacterial cultures were identified according to simplified key for the tentative identification of typical strain of Bacillus species. As a result 8 strains were positive and further screened for antifungal activity against Fusarium spp and Alternaria solani. Out of these 8 strains 5 strains are selected based on their high effectiveness against fungal pathogens and for further confirmation Polymerase Chain reaction run for effective bacterial strains using specific primers B.Lich-f and B.Lich-r. 

scholarly journals RNA interference approaches for plant disease control

BioTechniques ◽  
2020 ◽  
Vol 69 (6) ◽  
pp. 469-477
Author(s):  
Yen-Wen Kuo ◽  
Bryce W Falk
Keyword(s):  
Rna Interference ◽  
Disease Control ◽  
Crop Production ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Control Plant ◽  
Cost Effective ◽  
Plant Diseases ◽  
Natural Ecosystems ◽  
Plant Disease Control

Plant diseases caused by a variety of pathogens can have severe effects on crop plants and even plants in natural ecosystems. Despite many effective conventional approaches to control plant diseases, new, efficacious, environmentally sound and cost-effective approaches are needed, particularly with our increasing human population and the effects on crop production and plant health caused by climate change. RNA interference (RNAi) is a gene regulation and antiviral response mechanism in eukaryotes; transgenic and non transgenic plant-based RNAi approaches have shown great effectiveness and potential to target specific plant pathogens and help control plant diseases, especially when no alternatives are available. Here we discuss ways in which RNAi has been used against different plant pathogens, and some new potential applications for plant disease control.

scholarly journals A small secreted protein from Zymoseptoria tritici interacts with a wheat E3 ubiquitin ligase to promote disease

2020 ◽  
Author(s):  
Sujit Jung Karki ◽  
Aisling Reilly ◽  
Binbin Zhou ◽  
Maurizio Mascarello ◽  
James Burke ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Plant Pathogens ◽  
Plant Immunity ◽  
E3 Ubiquitin Ligase ◽  
Bimolecular Fluorescence Complementation ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Virus Induced Gene Silencing ◽  
In Planta ◽  
Zymoseptoria Tritici

Abstract Septoria tritici blotch (STB), caused by the ascomycete fungus Zymoseptoria tritici, is a major threat to wheat production worldwide. The Z. tritici genome encodes many small secreted proteins (ZtSSPs) that are likely to play a key role in the successful colonization of host tissues. However, few of these ZtSSPs have been functionally characterized for their role during infection. In this study, we identified and characterized a small, conserved cysteine-rich secreted effector from Z. tritici which has homologues in other plant pathogens in the Dothideomycetes. ZtSSP2 was expressed throughout Z. tritici infection in wheat, with the highest levels observed early during infection. A yeast two-hybrid assay revealed an interaction between ZtSSP2 and wheat E3 ubiquitin ligase (TaE3UBQ) in yeast, and this was further confirmed in planta using bimolecular fluorescence complementation and co-immunoprecipitation. Down-regulation of this wheat E3 ligase using virus-induced gene silencing increased the susceptibility of wheat to STB. Together, these results suggest that TaE3UBQ is likely to play a role in plant immunity to defend against Z. tritici.

scholarly journals Use of Competitive Filamentous Fungi as an Alternative Approach for Mycotoxin Risk Reduction in Staple Cereals: State of Art and Future Perspectives

Toxins ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 701 ◽  
Author(s):  
Sabrina Sarrocco ◽  
Antonio Mauro ◽  
Paola Battilani
Keyword(s):  
Filamentous Fungi ◽  
Plant Pathogens ◽  
Plant Protection ◽  
Interference Competition ◽  
Control Plant ◽  
Plant Protection Products ◽  
Plant Diseases ◽  
Head Blight ◽  
Mycotoxigenic Fungi ◽  
Beneficial Fungi

Among plant fungal diseases, those affecting cereals represent a huge problem in terms of food security and safety. Cereals, such as maize and wheat, are very often targets of mycotoxigenic fungi. The limited availability of chemical plant protection products and physical methods to control mycotoxigenic fungi and to reduce food and feed mycotoxin contamination fosters alternative approaches, such as the use of beneficial fungi as an active ingredient of biological control products. Competitive interactions, including both exploitation and interference competition, between pathogenic and beneficial fungi, are generally recognized as mechanisms to control plant pathogens populations and to manage plant diseases. In the present review, two examples concerning the use of competitive beneficial filamentous fungi for the management of cereal diseases are discussed. The authors retrace the history of the well-established use of non-aflatoxigenic isolates of Aspergillus flavus to prevent aflatoxin contamination in maize and give an overview of the potential use of competitive beneficial filamentous fungi to manage Fusarium Head Blight on wheat and mitigate fusaria toxin contamination. Although important steps have been made towards the development of microorganisms as active ingredients of plant protection products, a reasoned revision of the registration rules is needed to significantly reduce the chemical based plant protection products in agriculture.

scholarly journals Natural gene drives offer potential pathogen control strategies in plants

2020 ◽  
Author(s):  
Donald M. Gardiner ◽  
Anca Rusu ◽  
Luke Barrett ◽  
Gavin C. Hunter ◽  
Kemal Kazan
Keyword(s):  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Control Strategies ◽  
Control Plant ◽  
Current Control ◽  
Plant Diseases ◽  
List Type ◽  
Gene Drive ◽  
Genetic Management ◽  
Pathogen Populations

SummaryGlobally, fungal pathogens cause enormous crop losses and current control practices are not always effective, economical or environmentally sustainable. Tools enabling genetic management of wild pathogen populations could potentially solve many problems associated with plant diseases.A natural gene drive from a heterologous species can be used in the globally important cereal pathogen, Fusarium graminearum, to remove pathogenic traits from contained populations of the fungus. The gene drive element became fixed in a freely crossing populations in only three generations.Repeat induce point mutation, a natural genome defence mechanism in fungi, may be useful to recall the gene drive following release, should a failsafe mechanism be required.We propose that gene drive technology is a potential tool to control plant pathogens.

scholarly journals Control Of Plant Diseases By An Allium-based Antimicrobial Formulation

2022 ◽  
Author(s):  
Oladejo Oluwashina ◽  
Jafargholi Imani
Keyword(s):  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Fruits And Vegetables ◽  
Antimicrobial Properties ◽  
Field Application ◽  
Plant Diseases ◽  
In Planta ◽  
Xanthomonas Fragariae ◽  
Alternaria Dauci

The objective of this work was to determine the antimicrobial properties of an allium-based antimicrobial formulation named VEG’LYS (https://phytoauxilium.com/) on the growth of plant pathogenic microorganisms such as fungi, oomycetes, and bacteria. Two anthracnose-related species of the fungal genus Colletotrichum, C. gloeosporioides, and C. fragariae, the oomycete Phytophthora cactorum and the bacterium Xanthomonas fragariae associated with strawberry plants and two fungi Alternaria dauci and Botrytis cinerea, associated with carrot plants were tested in vitro. In in planta experiments, A. dauci and B. cinerea were used.. VEG’LYS inhibited the growth of all plant pathogens tested. We found that both curative and preventive in planta treatments with VEG’LYS inhibited the growth of A. dauci and B. cinerea in carrot. Furthermore, after spraying VEG’LYS on carrot plants the expression of the Pathogenesis-related (PR) 10 gene correlated with the magnitude of infection both in treated and untreated plants. Additionally, it has been shown, that the field application of VEG’LYS on strawberry plants results in a reduction of bacterial and fungal pathogens of strawberry fruits stored in refrigerator. In summary, VEG’LYS is a potential resistance inducer that seems to be suitable for use in both curative and preventive treatments to reduce the diseases and rotting of fruits and vegetables caused by different plant pathogens.

scholarly journals Transcriptome landscape of a bacterial pathogen under plant immunity

2018 ◽  
Vol 115 (13) ◽  
pp. E3055-E3064 ◽  
Author(s):  
Tatsuya Nobori ◽  
André C. Velásquez ◽  
Jingni Wu ◽  
Brian H. Kvitko ◽  
James M. Kremer ◽  
...  
Keyword(s):  
Immune Response ◽  
Pseudomonas Syringae ◽  
Bacterial Growth ◽  
Plant Pathogens ◽  
Plant Immunity ◽  
Expression Patterns ◽  
Bacterial Pathogen ◽  
In Planta ◽  
Bacterial Strains ◽  
Bacterial Genes

Plant pathogens can cause serious diseases that impact global agriculture. The plant innate immunity, when fully activated, can halt pathogen growth in plants. Despite extensive studies into the molecular and genetic bases of plant immunity against pathogens, the influence of plant immunity in global pathogen metabolism to restrict pathogen growth is poorly understood. Here, we developed RNA sequencing pipelines for analyzing bacterial transcriptomes in planta and determined high-resolution transcriptome patterns of the foliar bacterial pathogen Pseudomonas syringae in Arabidopsis thaliana with a total of 27 combinations of plant immunity mutants and bacterial strains. Bacterial transcriptomes were analyzed at 6 h post infection to capture early effects of plant immunity on bacterial processes and to avoid secondary effects caused by different bacterial population densities in planta. We identified specific “immune-responsive” bacterial genes and processes, including those that are activated in susceptible plants and suppressed by plant immune activation. Expression patterns of immune-responsive bacterial genes at the early time point were tightly linked to later bacterial growth levels in different host genotypes. Moreover, we found that a bacterial iron acquisition pathway is commonly suppressed by multiple plant immune-signaling pathways. Overexpression of a P. syringae sigma factor gene involved in iron regulation and other processes partially countered bacterial growth restriction during the plant immune response triggered by AvrRpt2. Collectively, this study defines the effects of plant immunity on the transcriptome of a bacterial pathogen and sheds light on the enigmatic mechanisms of bacterial growth inhibition during the plant immune response.

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