scholarly journals In Planta Localization of Endophytic Cordyceps fumosorosea in Carrizo Citrus

2021 ◽  
Vol 9 (2) ◽  
pp. 219
Author(s):  
Ethan M. Doherty ◽  
Pasco B. Avery ◽  
Emily B. Duren ◽  
Liliana M. Cano ◽  
Lorenzo Rossi
Keyword(s):  
Plant Pathogens ◽  
Foliar Spray ◽  
In Planta ◽  
Sand Column ◽  
Diaprepes Abbreviatus ◽  
Citrus Plant ◽  
Soil Drench ◽  
Carrizo Citrange ◽  
Inoculation Techniques ◽  
Stem Injection

Entomopathogenic fungi can be a useful resource for controlling insect vectors of citrus plant pathogens, such as the Asian citrus psyllid (Diaphorina citri) associated with huanglongbing or the citrus root weevil (Diaprepes abbreviatus) associated with the spread of Phytophtora spp. In this study, Cordyceps fumosorosea (Cfr) was investigated in planta as a potential endophytic entomopathogenic fungus and various inoculation techniques were used to determine if it would colonize the Carrizo citrange (Citrus × insitorum) seeds and plants. The four inoculation methodologies evaluated were seed soaking, stem injection, foliar spray, and soil drench. Seed immersion trials demonstrated that the roots of the Carrizo citrange plant can be inoculated successfully with Cfr. Stem injection, foliar spray, and soil drench also provided successful inoculation of Cfr. However, this fungus was only endophytic in the plant stem. Sand cores indicated that Cfr moved down through the sand column and was able to inoculate the roots. Given the prevalence of Cfr in the soil during the drench experiment, and that the fungus was able to colonize Carrizo citrange roots through seed immersion, this finding provides evidence of the potential endophytism of this fungus when applied to citrus plant species.

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 PHIALOMYCES MACROSPORUS REDUCES CERCOSPORA COFFEICOLA SURVIVAL ON SYMPTOMATIC COFFEE LEAVES

2019 ◽  
Vol 14 (1) ◽  
pp. 1
Author(s):  
Marie Caroline Ferreira Laborde ◽  
Deila Magna dos Santos Botelho ◽  
Gabriel Alfonso Alvarez Rodriguez ◽  
Mário Lúcio Vilela de Resende ◽  
Marisa Vieira de Queiroz ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Disease Rate ◽  
In Planta ◽  
Necrotrophic Pathogen ◽  
Initial Inoculum ◽  
Saprobe Fungi ◽  
Cercospora Coffeicola ◽  
Brown Eye Spot

<p>Saprobe fungi and necrotrophic pathogens share the same niche within crop stubble and the search for fungi non-pathogenic to plants that are able to displace the plant pathogens from its overwintering substrate contributes to the disease management. Brown eye spot (<em>Cercospora coffeicola</em>) is among the most important coffee diseases, it is caused by a necrotrophic pathogen that has decaying leaves as its major source of inoculum. We have screened saprobe fungi for the ability to reduce <em>C. coffeicola</em> sporulation and viability and determined the possible mechanisms involved in the observed biocontrol. A selected saprobe fungus, <em>Phialomyces macrosporus</em>, reduced the pathogen’s viability by 40% both <em>in vitro</em> and <em>in vivo</em>. The fungus acts through antibiosis and competition for nutrients. It produced both volatile and non-volatile compounds that inhibited <em>C. coffeicola</em> growth, sporulation, and viability. It also produced the tissue maceration enzyme (polygalacturonase), which reduces the pathogen both in detached leaves or in planta. The reduction in the fungal viability either by the saprobe fungus or its polygalacturonase-fraction supernatant resulted in the reduction of the disease rate. Therefore, <em>P. macrosporus </em>is a potential microbial agent that can be used in an integrated management of brown eye spot through the reduction of the initial inoculum of the pathogen that survives and builds up in infected leaves.</p><p> </p>

scholarly journals Evaluation of in-vitro methods to select effective streptomycetes against toxigenic fusaria

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6905 ◽  
Author(s):  
Elena Maria Colombo ◽  
Cristina Pizzatti ◽  
Andrea Kunova ◽  
Claudio Gardana ◽  
Marco Saracchi ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Culture Media ◽  
Screening Methods ◽  
Dual Culture ◽  
In Planta ◽  
In Vitro Method ◽  
In Vitro Methods ◽  
Strain Diversity ◽  
Fungal Plant Pathogens

Biocontrol microorganisms are emerging as an effective alternative to pesticides. Ideally, biocontrol agents (BCAs) for the control of fungal plant pathogens should be selected by an in vitro method that is high-throughput and is predictive of in planta efficacy, possibly considering environmental factors, and the natural diversity of the pathogen. The purpose of our study was (1) to assess the effects ofFusariumstrain diversity (N= 5) and culture media (N= 6) on the identification of biological control activity ofStreptomycesstrains (N= 20) againstFusariumpathogens of wheat in vitro and (2) to verify the ability of our in vitro screening methods to simulate the activity in planta. Our results indicate that culture media,Fusariumstrain diversity, and their interactions affect the results of an in vitro selection by dual culture assay. The results obtained on the wheat-based culture media resulted in the highest correlation score (r= 0.5) with the in planta root rot (RR) inhibition, suggesting that this in vitro method was the best predictor of in planta performance of streptomycetes against Fusarium RR of wheat assessed as extension of the necrosis on the root. Contrarily, none of the in vitro plate assays using the media tested could appropriately predict the activity of the streptomycetes against Fusarium foot rot symptoms estimated as the necrosis at the crown level. Considering overall data of correlation, the activity in planta cannot be effectively predicted by dual culture plate studies, therefore improved in vitro methods are needed to better mimic the activity of biocontrol strains in natural conditions. This work contributes to setting up laboratory standards for preliminary screening assays ofStreptomycesBCAs against fungal pathogens.

scholarly journals Effect of Bioplex™ on Transplant Success of Non-Dormant Red Oak (Quercus rubra L.)

2004 ◽  
Vol 22 (4) ◽  
pp. 197-201
Author(s):  
Jonathan D. Sammons ◽  
Daniel K. Struve
Keyword(s):  
Water Use ◽  
Foliar Spray ◽  
Root Surface ◽  
Root Surface Area ◽  
Red Oak ◽  
Root Pruning ◽  
Soil Drench ◽  
Whole Plant ◽  
Nursery Stock ◽  
Before And After

Abstract Biostimulants are used to reduce the stress associated with non-dormant (summer dug) harvest of field-grown nursery stock; however, the effectiveness of biostimulant treatment is uncertain. This study tested the effects of three application methods of Bioplex™ (a commonly used biostimulant) to container-grown red oak seedlings on whole plant transpirational water use and growth before and after root pruning. Root pruning was used to simulate field harvest; it removed 59% of the seedling's total root surface area. Bioplex™ application by foliar spray, soil drench or a combination of foliar spray and soil drench, significantly reduced whole plant transpirational water use by 15% for three days after application, relative to untreated control seedlings. Root pruning significantly reduced whole plant transpiration, compared to non-root-pruned seedlings, and had a greater effect on transpiration than any Bioplex™ treatment. The previous season's Bioplex treatment had no effect on the spring growth flush following fall root pruning. Root pruning in fall significantly reduced root and total plant dry weights the following spring. Although Bioplex™ applications significantly reduced transpiration for three days after application, there does not seem to be any long-term beneficial effect when used to mediate summer digging transplant stress.

scholarly journals The in Planta Effective Concentration of Oxytetracycline Against ‘Candidatus Liberibacter asiaticus’ for Suppression of Citrus Huanglongbing

2019 ◽  
Vol 109 (12) ◽  
pp. 2046-2054 ◽  
Author(s):  
Jinyun Li ◽  
Zhiqian Pang ◽  
Shuo Duan ◽  
Donghwan Lee ◽  
Vladimir G. Kolbasov ◽  
...  
Keyword(s):  
Field Experiments ◽  
Foliar Spray ◽  
Effective Control ◽  
Candidatus Liberibacter Asiaticus ◽  
In Planta ◽  
Fresh Tissue ◽  
Minimum Concentration ◽  
Candidatus Liberibacter ◽  
Liberibacter Asiaticus ◽  
Residue Levels

Huanglongbing (HLB) or greening currently is the most devastating citrus disease worldwide. The fastidious phloem-colonizing bacterium ‘Candidatus Liberibacter asiaticus’ (CLas) is the causal agent of citrus HLB in Florida. Bactericides containing the active ingredient oxytetracycline (OTC) have been used in foliar spray to control citrus HLB in Florida since 2016. However, the minimum concentration of OTC required to suppress CLas in planta remains unknown. We developed a new method for evaluating the effects of OTC treatment on CLas titers in infected plants and determined the relationship between OTC residue levels and control levels achieved for CLas using mathematical modeling in greenhouse and field experiments. In both greenhouse and field, OTC spray did not reduce the titers of CLas, and it produced undetectable or mild levels of OTC residue in leaves within 7 days post-application (DPA). In greenhouse, OTC injection at 0.05 g per tree decreased CLas titers to an undetectable level (cycle threshold value ≥ 36.0) from 7 to 30 DPA and produced a residue level of OTC at 0.68 to 0.73 µg/g of fresh tissue over this period. In the field, OTC injection at 0.50 g per tree resulted in the decline of CLas titers by 1.52 log reduction from 14 to 60 DPA, with residue levels of OTC at 0.27 to 0.33 µg/g of fresh tissue. In both trials, a first-order compart model of OTC residue dynamics in leaves of trunk-injected trees was specified for estimating the retention of effective concentrations. Furthermore, nonlinear modeling revealed significant positive correlations between OTC residue levels in leaves and the control levels for CLas achieved. The results suggested that the minimum concentrations of OTC required to suppress CLas populations in planta to below the detection limit are 0.68 and 0.86 µg/g and that the minimum concentrations of OTC required for initial inhibition of CLas growth in planta are ∼0.17 and ∼0.215 µg/g in leaf tissues under greenhouse and field conditions, respectively. This finding highlights that a minimum concentration of OTC should be guaranteed to be delivered to target CLas in infected plants for effective control of citrus HLB.

scholarly journals Standardization of inoculation techniques for sheath blight of rice caused by Rhizoctonia solani (Kuhn)

2019 ◽  
Vol 48 (4) ◽  
pp. 1107-1113
Author(s):  
Santosh Kumar ◽  
Md Nadeem Akhtar ◽  
Erayya ◽  
Tribhuwan Kumar
Keyword(s):  
Rice Variety ◽  
Foliar Spray ◽  
Relative Number ◽  
Sheath Blight ◽  
Lesion Length ◽  
Inoculum Sources ◽  
Soil Inoculation ◽  
Inoculation Techniques ◽  
Disease Rating ◽  
Mycelial Suspension

To develop a simple and reliable inoculation technique using inoculum sources viz., mycelial suspension, mycelial ball, sclerotia and soil inoculation with homogenized mycelia suspension was carried out. The efficiency of different inoculation techniques were tested on susceptible rice variety Rejendra Sweta. Sheath inoculation with sclerotia gave lesion length 10.33 and 12.33 cm after seven and 15 days of inoculation, respectively. It also shows more significance in terms of relative lesion height to plant height i.e. 30.06 % followed by soil inoculation with homogenized mycelial suspension i.e. 21.62 %. However, relative number of lesions as compared to control was found to be maximum (429.18%) in mycelial suspension spray, followed by soil inoculation using homogenized mycelia suspension (400.43%). The disease rating of sheath blight of rice was also found to be maximum (5) in sheath inoculation with sclerotia followed by soil inoculation of mycelial suspension (3). The disease rating was minimum (1) in sheath inoculation with mycelial ball and foliar spray with mycelial suspension.

CONTROL OF SPRUCE BUDMOTH, ZEIRAPHERA CANADENSIS MUT. AND FREE., IN WHITE SPRUCE PLANTATIONS WITH ENTOMOPATHOGENIC NEMATODES, STEINERNEMA SPP.

1991 ◽  
Vol 123 (2) ◽  
pp. 379-385 ◽  
Author(s):  
D.C. Eidt ◽  
Gary B. Dunphy
Keyword(s):  
Bacillus Thuringiensis ◽  
Entomopathogenic Nematodes ◽  
Foliar Spray ◽  
White Spruce ◽  
Steinernema Carpocapsae ◽  
Infective Juvenile ◽  
Soil Drench ◽  
Population Reduction

AbstractA spruce budmoth population reduction of 82%, as measured by moth emergence, was realized after a foliar spray in which Futura®, a commercial Bacillus thuringiensis Berliner (B.t.) formulation, was added to a suspension of Steinernema carpocapsae (Weiser). The nematode suspension, which took advantage of the wetting and spreading agents in the formulation, was applied to runoff at the rate of 9785 viable infective juvenile nematodes per litre. Mortality was attributed to the nematodes; B.t. was not available to the cryptic larvae. Soil drench treatments were encouraging, and suggested that applications of nematodes to the soil may be feasible.

scholarly journals Identification of Loci of Pseudomonas syringae pv. actinidiae Involved in Lipolytic Activity and Their Role in Colonization of Kiwifruit Leaves

2017 ◽  
Vol 107 (6) ◽  
pp. 645-653 ◽  
Author(s):  
Hitendra Kumar Patel ◽  
Patrizia Ferrante ◽  
Meng Xianfa ◽  
Sree Gowrinadh Javvadi ◽  
Sujatha Subramoni ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Plant Pathogens ◽  
Lipid A ◽  
Lipolytic Activity ◽  
Genetic Screen ◽  
Economic Losses ◽  
In Planta ◽  
Tn5 Transposon ◽  
Tn5 Mutants ◽  
Transposon Mutants

Bacterial canker disease caused by Pseudomonas syringae pv. actinidiae, an emerging pathogen of kiwifruit plants, has recently brought about major economic losses worldwide. Genetic studies on virulence functions of P. syringae pv. actinidiae have not yet been reported and there is little experimental data regarding bacterial genes involved in pathogenesis. In this study, we performed a genetic screen in order to identify transposon mutants altered in the lipolytic activity because it is known that mechanisms of regulation, production, and secretion of enzymes often play crucial roles in virulence of plant pathogens. We aimed to identify the set of secretion and global regulatory loci that control lipolytic activity and also play important roles in in planta fitness. Our screen for altered lipolytic activity phenotype identified a total of 58 Tn5 transposon mutants. Mapping all these Tn5 mutants revealed that the transposons were inserted in genes that play roles in cell division, chemotaxis, metabolism, movement, recombination, regulation, signal transduction, and transport as well as a few unknown functions. Several of these identified P. syringae pv. actinidiae Tn5 mutants, notably the functions affected in phosphomannomutase AlgC, lipid A biosynthesis acyltransferase, glutamate–cysteine ligase, and the type IV pilus protein PilI, were also found affected in in planta survival and/or growth in kiwifruit plants. The results of the genetic screen and identification of novel loci involved in in planta fitness of P. syringae pv. actinidiae are presented and discussed.

scholarly journals Potential of a Small Molecule Carvacrol in Management of Vegetable Diseases

Molecules ◽  
2019 ◽  
Vol 24 (10) ◽  
pp. 1932 ◽  
Author(s):  
Qingchun Liu ◽  
Kang Qiao ◽  
Shouan Zhang
Keyword(s):  
Small Molecule ◽  
Plant Pathogens ◽  
The United States ◽  
South Florida ◽  
Human Consumption ◽  
Vegetable Crops ◽  
In Planta ◽  
Xanthomonas Perforans ◽  
Promising Tool ◽  
The Usa

Carvacrol, a plant-derived volatile small molecule, is effective against various agents that can cause damage to humans, the food processing industry, and plants, and is considered a safe substance for human consumption. In this short communication, previous studies on the effectiveness of carvacrol against various agents, particularly plant pathogens and their associated mechanisms are described. In our study, carvacrol was found to be effective on media against several soilborne pathogens and in planta against three foliar pathogens (Xanthomonas perforans, Alternaria tomatophila, and Podosphaeraxanthii) of important vegetable crops in south Florida of the United States. Current research findings indicated that the effectiveness of carvacrol against various plant pathogens tested was associated with its direct bactericidal/fungicidal effect, which was affected greatly by its volatility. Development of new formulations to overcome the volatility and to prolong the effectiveness of carvacrol was also presented. Our studies on carvacrol suggested that, with advanced development of new formulations, carvacrol could be used as a promising tool in the integrated pest management for bacterial, fungal, and viral pathogens of important vegetable crops in Florida, the USA, and the world.

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