Science topic

plant pathogens - Science topic

Explore the latest questions and answers in plant pathogens, and find plant pathogens experts.
Questions related to plant pathogens
  • asked a question related to plant pathogens
Question
3 answers
I am looking for the protocol(s) to evaluate the antifungal properties of some PGPRs against soil-borne plant pathogens in lab conditions. Kindly guide me. Thank you.
Relevant answer
Answer
Hi Muhammad,
There are several methods to test antifungal activity of bacteria (or PGPRs) against soil-borne (bacterial/fungal) plant pathogens in vitro using petri plates.
The most common one is called "Dual-culture assay, also known as co-culture". It means that you will co-culture your bacteria with a pathogen in a same petri plate to see antagonistic actions (PDA or solid medium required).
Another one can be "microtiter broth dilution method", which requires culture broth of your PGPRs. Using this method, you can not only determine the inhibitory activity of your PGPRs, but also the minimum inhibitory concentration (MIC) of your culture broth.
Both of these methods are thoroughly described in our Biocontrol paper, which is available at
Good luck,
  • asked a question related to plant pathogens
Question
3 answers
Are plant pathogens belonging to same strain affecting both humans and animals?
Relevant answer
Answer
Biswajit Jena this question has been discussed in RG several times before.
Yes, there are several examples of human infection by plant pathogens, including fungi (for instance: Fusarium solani, F. oxysporum), bacteria (Pantoea, Burkholderia, Serratia, Klebsiella, Agrobacterium, Listeria), cases of virus infection are controversial. Animal pathogens (enterobacteria, some viruses were identified by RNAseq) are common in plants without disease symptoms
  • asked a question related to plant pathogens
Question
6 answers
I was wondering for how much time does a mycelium freshly isolated from plant tissue continue to be "similar to what it used to be" in nature. I can see that morphological changes frequently occur when transferring from plate to plate so in short, my question is: can I keep using a mycelium for a long time, making sure it still is the same? Should I re-isolate it from time to time? And, are there some techniques to prevent changes to happen?
Relevant answer
Answer
Dear Alessndro,
It depends on the type of fungus. Generally, you must not preserve the fungus with this method for a long time. You can use another methods for preserving the fungi for a long time such as glycerol 10%, lyophilization, liquid nitrogen.
Regards
  • asked a question related to plant pathogens
Question
5 answers
I found a genus of fungi, which was previously defined by some scholars as not pathogenic bacteria, but the samples I collected recently are all in line with plant pathogenic bacteria. Does anyone know how to identify plant pathogenic bacteria or recommend related literatures
Relevant answer
Answer
If you have found that some bacterum, previously described as non-pathogenic, was capable to infect plants, you need to prove that it is pathogenic indeed (Koch's postulates), and identify to the species level by one or two of the methods: MLST/FAME/MALDI TOF or BIOLOG analysis.
  • asked a question related to plant pathogens
Question
2 answers
Normally in bacteria, both sexual and asexual reproduction occurs. In the case of Plant pathogenic bacteria, I only get the mention of binary fission and reproduction by means of spore in some bacteria. Even in the book of G.N Agrios, there is mention of only fission and spores as a means of reproduction. Isn't there a mention of sexual reproduction like conjugation, transduction, etc in Plant Pathogenic Bacteria? Need Help.
Relevant answer
Answer
Who has taught you that bacteria have sexual reproduction? In the prokaryotic world, we do not have miosis as well as sexual reproduction.
conjugation, transduction, or transfection are only considered as genetic exchange information with each other. Nobody calls them sexual reproduction
  • asked a question related to plant pathogens
Question
6 answers
Peracetic acid (also known as peroxyacetic acid, or PAA) is registered antimicrobial in USA (1985) and European Union (2013). It was used for post-harvest plant treatment (Abd-Alla MA, Abd-El-Kader MM, Abd-El-Kareem F, El-Mohamedy RS. Evaluation of lemongrass, thyme and peracetic acid against gray mold of strawberry fruits. Journal of Agricultural Technology. 2011;7(6):1775-87.)
It is recommended for plant treatment (0.15% solution) against a wide range of pathogens. But, is there any confirmed trials of antiviral, antibacterial or fungicidal properties in field or greenhouse application of PAA?
Relevant answer
Answer
Yuan-Yeu Yau Residues of PAA - only acetic acid and H2O2 that turns finally to water and O2. The only problem - PAA smells like acetic acid.
  • asked a question related to plant pathogens
Question
6 answers
Okra seedlings were raised.
Pathogen inoculation was done during sowing.
This was followed by biological control.
Relevant answer
  • asked a question related to plant pathogens
Question
3 answers
Unfortunately, we came across tragedy in our personal apple garden and a few of our trees have majorly infected by Fire Blight pathogenic agent. I have attached a few photos of infected trees, I think there is a relationship between the white stains on the bark of the tree and diseases outbreak. I think the more white spots there are, the more the tree is exposed to the disease. However, this is my experimental understanding and I have no academic expertise in this field. That disease has appeared only on the red apple trees.  
I would be very happy if you put me in the right pass and let me know how I can overcome that disease. 
Sincerely yours 
Bagher
Relevant answer
Answer
Below mentioned suggestions might be helpful to you -
Select resistant varieties whenever possible.
  1. Avoid heavy pruning or excess applications of nitrogen fertilizer, both of which encourage new growth.
  2. Avoid planting close to wild plants of hawthorn, apple or pear.
  3. As soon as fire blight is discovered, prune off infected branches 1 foot below the diseased sections and burn them to prevent further infection. Dip pruning shears into a 10% alcohol or bleach solution between each cut to avoid transmitting the disease from one branch to another.
  4. Early applications of liquid copper are effective against this plant problem. Mix 0.5 to 2.0 oz per gallon of water and apply at silver tip and bud break — repeat at 3 to 5 day intervals up to petal fall. Use the lower rate if disease pressure is light and the higher rate when conditions favor heavy disease pressure.
  5. Bacterial spread can be reduced by applications of products that contain Streptomyces lydicus as the active ingredient. To obtain best disease control, applications should be made at the start of the bloom period and every five to seven days thereafter.
  6. SERENADE Garden is a broad spectrum, preventative bio-fungicide recommended for the control or suppression of many important plant diseases. For best results, treat prior to foliar disease development or at the first sign of infection. Repeat at 7-day intervals or as needed.
  7. The systemic action of Organocide® Plant Doctor moves throughout the entire plant to treat most common disease problems. Mix 2-1/2 to 5 tsp per gallon of water and apply to foliage. Spray to run-off, as required for disease control.
  • asked a question related to plant pathogens
Question
4 answers
I've been using Qiagen DNeasy Plant Pro kits to extract plant pathogen DNA from diseased plant material. Unfortunately the Lysis Buffer (Solution CD1) has been spilt whilst there are still 137 tests left (arrgh!). Currently replacement Plant Pro kits are hard to come by, so I am trying to find out where I might be able to obtain some replacement solution CD1 or possibly a recipe for a lysis buffer that will work with the Plant Pro kit.
Relevant answer
Answer
Lysis buffer in kits is not a very critical reagent and I don't think its replacement with any lysis buffer from other kits or lysis buffer from std. CTAB method would make a huge difference. If you have some samples to spare, a few replicate extractions can easily be done to check the efficiency or differences.
  • asked a question related to plant pathogens
Question
23 answers
I observed the attached symptoms on Eucalyptus.
Do you have any idea what causes these symptoms?
When I tried to remove it, in was hard to be removed. It looks like tumors.
Thanks in advance,
Mustafa
Relevant answer
Answer
Please have a look at the following RG link for better insights.
  • asked a question related to plant pathogens
Question
12 answers
steril control of a mineral substrats for plants
grow medium: sabouraud agar
sample 8
tia
Relevant answer
Answer
The above micrograph shows penicillium spp.
  • asked a question related to plant pathogens
Question
7 answers
sterile control of a mineral substrate for plants
grow medium: sabouraud agar
tia
Relevant answer
Answer
The colony which limited with yellow marker with white mycelium may be belong to the fungus Beauveria bassiana, but not exactly. It needs more images to clearly identified.
  • asked a question related to plant pathogens
Question
5 answers
Spray-induced gene silencing, SIGS, is tested for plant diseases control. Is there any results on dsRNA formulation trials that showed long life for dsRNA in a product and an efficient transport into plants/pathogens/pests?
Relevant answer
Answer
Hi Alex
I think this paper is useful for you about the exogenous application of double-stranded RNA
"RNA Interference Strategies for Future Management of Plant Pathogenic Fungi: Prospects and Challenges"
  • asked a question related to plant pathogens
Question
3 answers
Can the hypersensitive response occur as part of PAMP-Triggered Immunity (PTI) as well as Effector-Triggered Immunity (ETI)?
Relevant answer
Answer
Dear @Ruby Metzner
The ubiquity of hypersensitive response among higher plants despite its costs suggests that it is an extremely effective component of the plant immune system. Please check the following links, and attached pdfs; hope, these could be useful to you.
  • asked a question related to plant pathogens
Question
4 answers
Are resistance (R) proteins (encoded by R genes) involved in pathogen Avr protein recognition/interaction only? Or do genes associated with plant immune signalling or other pathogen defence mechanisms also fall into the category of R gene? For example pathogeneis related (PR) protein encoding genes or genes involved in salicylic acid signalling?
Relevant answer
Answer
Most identified R genes are polymorphic in plant populations, which led to their initial characterization and use in plant breeding programs. However, individual plants have up to a few hundred R gene analogs that make no identified contribution to resistance. Many of these R gene analogs are also fixed in plant species and are thought to contribute to non-host resistance. After more than 25 years of R gene cloning, R genes have been classified by Nine Mechanisms, details of which may be accessed at:
  • asked a question related to plant pathogens
Question
4 answers
A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPSs). The cells within the biofilm produce the EPS components, which are typically a polymeric conglomeration of extracellular polysaccharides, proteins, lipids and DNA. Because they have a three-dimensional structure and represent a community lifestyle for microorganisms, they have been metaphorically described as "cities for microbes".
Greenhouses and nurseries are particularly vulnerable to biofilm, a complex structure adhering to surfaces that are regularly in contact with water, consisting of colonies of bacteria that secrete a protective coating in which they are encased. Light is not necessary to create a biofilm. It is easily created in nutrient-rich environments such as a greenhouse irrigation system, where an ample supply of fertilizer-injected water assures an ample food supply to the bacteria.
Biofilm is created very quickly and needs to be continuously treated. If not treated, your irrigation system becomes a distribution point for detached biofilm clogging irrigation lines and emitters, which leads to extra labour, crop shrink, and irrigation equipment costs.
In this case, this farmer from Moguer (Huelva, Spain) had a serious problem with the creation of biofilm in his irrigation system, clogging the drippers and leaving several hectares without being irrigated, generating serious losses in such an expensive crop as raspberries.
Changing pipes and irrigation systems for new ones worked for a while, but they quickly went back to the same old ones. And the cost of personnel to replace these irrigation systems, and the material costs, made this crop unviable.
What would you do to solve this problem? (watch video)
Relevant answer
Answer
Biofilms are a recurrent problem in any nutrient rich circulating system. Other than periodically disinfection of the system with high pressure vapor (if its built with a suitable material) and using high power UV light or giving it a time residence within an ozone bubbling tank at some point of the recirculation system to lower the amount of CFUs, I can think only of another approach that is more alternative and not mainstream,
as it has been since long known that bacterial loads can be reduced with by adding some so called “colloidal“ silver ion solutions to the nutritive solution, I have seen excellent results of this in postharvest duration of flowers when used as a pulse dip before packing and also when used at the water in the flowerpot, chrysanthemum can last pristine for two months instead of two weeks with this treatment, without changing the water on the flowerpot at all.
  • asked a question related to plant pathogens
Question
4 answers
About 1/4 of field was affected by white heads symptoms. What can it be? Temperature range was high: 5 (night) - 30oC (day) within 4 last weeks.
Relevant answer
Answer
• Dryland root rot (also known as dryland foot rot). This disease, caused by the Fusarium fungus, causes white heads and often turns the base of the plants pinkish. As with take-all, dryland root rot causes all the tillers on an infected plant to have white heads. This disease is usually most common under drought stress conditions, and is often mistaken for either drought stress or take-all.
  • asked a question related to plant pathogens
Question
10 answers
Best methods suitable for isolation and purification of plant pathogenic fungi and bacteria from plant and soil samples....Latest methods....Any special advantages....Procedure to be followed...etc.
Relevant answer
Answer
For isolation, fungal media with antibiotics should be used to suppress bacterial contamination. Sabouraud's dextrose agar and potato-dextrose agar are commonly used media. Cultures are routinely incubated at 25° to 30° C for up to 4 weeks. Isolation of zygomycetous fungi can be difficult... https://www.sciencedirect.com/topics/immunology-and-microbiology/fungus-isolation
  • asked a question related to plant pathogens
Question
4 answers
Are pathogenesis-related proteins and antimicrobial peptides encoded by plant resistance genes (R genes)?
I'm unsure if the genes for these proteins/peptides are types of R genes?
  • asked a question related to plant pathogens
Question
2 answers
Hi everyone,
I work with the oospores (average diameter 27.7 µm) of a plant-pathogenic oomycete. In searching for antagonists of them, I incubate them with enzymes in solution or co-culture them with other microbes. I then assess viability changes using a combination of dyes - fluorescein diacetate and DITO-3 iodide.
My problem is that I always end up with a large amount of residual enzyme (and even buffer) or microbial residue in the tubes at the time of staining, which leads to many unexpected effects on the dyes (fluorescein diacetate in particular) and skewed results. I wash with sterile ultra-pure water and centrifugation twice before staining. I have tried adding more washes but it did not help and significantly increased the duration of the assay as well as increasing oospore loss (need to maintain oospore numbers for counting later on).
I have been thinking about filtration set-ups that might allow me to catch anything above, say, 15 µm and let through everything else. But I work with 24+ 1.5 ml tubes for each experiment, so the apparatus would need to work with this in mind and all the micro-centrifuge filtration options I can see are the typical 0.22/0.45 µm pore size (and would be a wasteful and expensive option anyway). Another limiting factor is the need to easily resuspend the oospores that I catch, in good numbers, to be stained. And this is a medium-throughput assay with small volumes, which also limits options.
I have also thought about flow cytometry/FACS, but the machines I have access to for these are on the other side of campus and would add an hr+ to an already long pipeline, where all I want is to reduce signal noise from residual enzymes. This option may be of more use down the line, when microbe-microbe interactions are a bigger focus.
Does anyone have any experience with this sort of very specific scenario? Or any ideas for how to more effectively wash my oospores clean before staining?
Relevant answer
Answer
You could collect your spores on the filters, then wash them as much as you want. Afterwards, you could resuspend them in a suitable liquid, then centrifuge them to remove the residual liquid. You would also need a vacuum device. I think it would still be difficult to get rid of all the bacteria this way, but it would probably work pretty well for the enzyme.
You could destroy the bacteria by treating them with lysozyme or a suitable antibiotic, such as penicillin. They would burst, making smaller particles that would be easier to filter.
You might be able to identify a potent inhibitor of the enzyme that you could add to eliminate any residual activity.
  • asked a question related to plant pathogens
Question
6 answers
Bio char is a type of charcoal used as a soil ameliorant for both carbon sequestration and soil health benefits and also being used for the management of soil borne plant pathogens but I doubt whether it will be an economic and ecofriendly approach for the management of plant diseases.
Relevant answer
Answer
Good question , could a possibility , but right now , such reports are miniscule in number....
  • asked a question related to plant pathogens
Question
5 answers
I need to understand most simple, and widely used method to study antagonistic activity of biocontrol bacteria against plant pathogenic bacteria.
Relevant answer
Answer
Some bacteria such as Pseudomonas flourescens and Bacillus subtilis can be used as antagonistic agent against plant pathogenic fungi such as Fusarium spp., Rhizoctonia solani, Macrophomina phaseolina... etc.
  • asked a question related to plant pathogens
Question
3 answers
Does anyone know if there are recent study about plant pathogenic fungi or invasive fungi surveillance? Such as sudden oak death or other important fungi.
Relevant answer
Answer
This is an excellent surveillance study on deadly wheat blast disease in Bangladesh. Hope it will be useful to you.
  • asked a question related to plant pathogens
Question
7 answers
The climate change is thought to affect the virulence of some known plant pathogens and can also lead to the emergence of new virulent strains. I want to know if the otherwise is possible?
Relevant answer
Answer
You are wecome dear Nawreen Mir.
I hope you all the best.
  • asked a question related to plant pathogens
Question
12 answers
Hi, Can plant pathogens cause disease and epidemics in humans? Do you have an example?
Relevant answer
Answer
Several fungi, such as Aspergillus niger, A.flavus, and Fusarium solani are plant pathogen.However, these fungi are known to produce disease in humans and animals including birds.We have mentioned about the pathogenic role of these phytopathgens (plant pathogens) in our book entitled " Veterinary and Medical Mycology" published by Indian Council of Agricultural Research, New Delhi, India.
  • asked a question related to plant pathogens
Question
4 answers
I have different fungus isolates such as;
1) Fusarium kyushuense , 2) Fusarium proliferatum ;3) Aspergillus aculeatus ;4) Aspergillus europaeus ; 5) Aspergillus flavus ; 6) Penicillium chermesinum ; 7) Microdochium phragmitis ;, 8) Cladosporium tenuissimum ;9) Colletotrichum truncatum ;10) Fusarium concentricum ; 11) Fusarium equiseti ; 12) Alternaria alternata
I want to do the pathogenicity testing, so
1: how old is the "fungal isolate" most suitable for pathogenicity testing on the surface of fruits?
2: which method is best for pathogenicity testing a) conidiospore suspension 1*10^6 /ml or b) through plugs
Relevant answer
Answer
  • asked a question related to plant pathogens
Question
4 answers
Electronic nose uses digital sensors which mimic human nose to identify a particular odour. In what way it finds application in plant pathology. If it can detect odour caused by rotting of a plant part due to a disease how the electronic nose is able to distinguish between odours caused by different plant pathogens
Relevant answer
Answer
Read this article Electronic nose classification and differentiation of bacterial foodborne pathogens based on support vector machine optimized with particle swarm optimization algorithm
  • asked a question related to plant pathogens
Question
4 answers
I have Penicillium isolates had highest antagonistic activities against the mycelial growth of plant pathogens in the dual culture technique test.
I am looking for help with any study on optimum using to kinds alcohol in extraction the bioactive compounds from the Penicillium sp.
with my great thanks
Relevant answer
Hi, Ali
I hope this article help you
best wishes
  • asked a question related to plant pathogens
Question
4 answers
Hi all,
I am working on proteomics, and I am looking for a plant pathogen updated database. Most of them are no longer available.
Thank you so much!
Relevant answer
Answer
Thanks @Kanugala Sirisha. I am looking for an updated plant pathogen database that I can use to determine presence of pathogenic proteins. I am not looking for any particular pathogen, I am screening the samples in order to validate a method. I found a list per plant from the The American Phytopathological Society (APS), but I am not sure how often they update this information. Any suggestions? Thanks again! Kanugala Sirisha
  • asked a question related to plant pathogens
Question
10 answers
I was collected my ten scale level data from from infected and control(non inoculated) by plant pathogen. Therefore, which statistical tools is appropriate for my data analysis?
Relevant answer
Answer
As your measurement scale indicates the interval scale, so it is better to go for parametric tests like t-test and others, I am strongly agreed with David L Morgan
  • asked a question related to plant pathogens
Question
7 answers
Hi everyone,
As part of my PhD program I would require some Verticillium dahliae for inoculations on olive plantlets, preferably VD pathotype D of known virulence.
Is there anyone working with this pathogen willing to share their isolates or perhaps to share an information on where to obtain them?
Would appreciate any information you can provide.
Thank you.
Regards,
Kristina
Relevant answer
Answer
You can obtain V. dahliae strains from ATCC from which some are pathogenic. If not possible and you have some isolates of this fungal plant pathogen you can molecularly characterize with help of few primers which show band at 334 and 462 bp (specific for Defoliating (D) type).
You can take help from the following article:
Jimenez-Diaz., et al (2011). Region-wide analysis of genetic diversity in Verticillium dahliae populations infecting olive in southern Spain and agricultural factors influencing the distribution and prevalence of vegetative compatibility groups and pathotypes. Phytopathology, 101(3), 304-315.
  • asked a question related to plant pathogens
Question
7 answers
I have seen different protocols abt leaf infection to deal with pathogenicity and control of plant pathogens especially when work focus on studying metabolomic and/ phenomics
Yet what are the performing critirea using only a leaf in the in vivo study especially when we know that there is more than the plant component that play the role in triggering pathogenicity and concluding/making decision in disease management strategies ?
Relevant answer
Answer
The assay you use depends on the question you are asking. For fungal pathogens, I don't like using detached leaf assays because the leaf is under stress and may not behave the way it would when attached to a plant, and if tissue age is an important factor, you may be adding uncertainty to the assay unless you use leaves that are exactly the same age. On the other hand, with detached leaves you can test many accessions simultaneously, quickly and inexpensively. I don't like wounding leaves because it makes it difficult to determine if the pathogen is a primary invader or a secondary invader. I don't like using agar plugs because some pathogens are good at infecting if they have a food base but poor at infecting when they don't. I like whole plant assays under controlled conditions, but I know that this also has its artifacts: If I infect a densely branched cultivar and a sparsely branched cultivar in a mist tent, they may show equal disease, but if I inoculated them in the field, the sparsely branched cultivar might show less disease because the dew dried more quickly. There is no bad assay, but for each assay you need to understand the assumptions you are making.
  • asked a question related to plant pathogens
Question
2 answers
please, attached articles if possible.
Relevant answer
Answer
Kindly go through the following PDF attachments.
  • asked a question related to plant pathogens
Question
5 answers
We isolate many species of Trichoderma .molecular identification revealed some of them are T.longibrachitum ,which exhibited high antagonistic activity against some plant pathogenic fungi,however we want to know if this species have been used as bio-agent.
Relevant answer
Answer
Thank You Dr.Abdulnabi
  • asked a question related to plant pathogens
Question
25 answers
It is difficult to work on crops and chances of successful experiments are very less, that is why we prefer these model organisms to study the mechanism and then apply the same knowledge on other crops. So, according to you, for different traits and developmental studies which is better?
Relevant answer
Answer
I have worked with Nicotiana tabacum and Arabidopsis thaliana. As for me tobacco is more easy culture to grow and work with. But for arabidopsis there is full genome and special resourse about genes and etc https://www.arabidopsis.org/
  • asked a question related to plant pathogens
Question
6 answers
What your opinion fora about partial and complete resistance to plant pathogens?
What your opinion for about tolerance?
Describe to us your concepts and uses?
Relevant answer
Answer
There is a researcher Raoul Robinson who favored the use of multiple genetic resistance because when it could breakdown the effects were not a highly susceptible reaction. He suggested that defeated resistance genes give a ghost level of partial resistance and if several of these genes are pyramided the effect is multi gene stable resistance. I am attaching a work which suggests if multiple Asian defeated resistance genes from Asian rust can be incorporated with genes working in Brazil the net result will be a stable multiple gene resistant type. Hope these concepts are useful for your breeding program.
  • asked a question related to plant pathogens
Question
13 answers
Pseudomonas corrugata causes pith necrosis of tomato, diseases of chrysantemium, geranium plants, isolated from roots of other crops, and applyed as biocontrol method against plant pathogenic fungi. Do you know any reports about Pseudomonas corrugata pathogenic for cucurbits?
Relevant answer
Answer
Jan, we have wilt and necrotic damage of stem and roots by mix of P. aptata and P. corrugata. P aptata on the top, and P. corrugata on the bottom of plants. I have seen similar complex disease on wheat P. atrofaciens on ears, P. syringae pv. syringae on leaves, P. viridiflava on bottom stem, P. cichorii & P. marginalis on roots.
  • asked a question related to plant pathogens
Question
17 answers
We already know that some Legumes are producing substances like thioglucosides and/ or isothiocyanates that kill plant pathogens in the soil. There must be other examples. Have you a recent reference. Thank you
Relevant answer
Answer
Following!
  • asked a question related to plant pathogens
Question
14 answers
I plan to assess the effect of compost tea on a specific soil-borne plant pathogen using soil bioassays. The general plan I have in mind is to sterilize the soil, inoculate it with the pathogen, and incubate it for a period of time. I will then apply compost tea on the inoculated soil.
Can someone suggest papers and/or methods on which I can base my methods on?
There is a lot of papers on the use of compost tea to suppress disease in pot based settings. However, I have yet to read papers which focuses only on the inhibition of pathogen growth in soil (not disease suppression) using compost tea.
Relevant answer
Answer
Dear Alba,
I think methodology to carry out the experiement that you posted is fine. But first you need a chemical and biological characterization of compost tea. Before to apply compost tea.
- what kind of soil do you have?
- what element, nutrients, microorganism, fenol, etc does your compost tea have?
  • asked a question related to plant pathogens
Question
2 answers
Plant pathogenic bacteria of genus Clavibacter were found in glacial ice across the World. (see Christner, B. C., Mosley-Thompson, E., Thompson, L. G., Zagorodnov, V., Sandman, K., & Reeve, J. N. (2000). Recovery and identification of viable bacteria immured in glacial ice. Icarus, 144(2), 479-485. and other publications). We have found it in underground waters used for irrigation. Is there any projects devoted to plant pathogens underground?
Relevant answer
Answer
Birol, thank you!
We have some data on plant pathogens in surface irrigation waters, and they are in very good agreement with diseases incidence in field. But, I mean the chance for presence of plant pathogens in deep subterranean waters. Some related to plant pathogens gram+ bacteria have been found already:
Kondakova GV, Verkhovtseva NV, Osipov GA. Investigation of microbial diversity of underground waters in monitoring deep horizons of the Earth’s crust. Moscow University Biological Sciences Bulletin. 2007 Jun 1;62(2):69-75.
Wu X, Holmfeldt K, Hubalek V, Lundin D, Åström M, Bertilsson S, Dopson M. Microbial metagenomes from three aquifers in the Fennoscandian shield terrestrial deep biosphere reveal metabolic partitioning among populations. The ISME journal. 2015 Oct 20;10(5):1192.
  • asked a question related to plant pathogens
Question
11 answers
We have a cucumber wilt that is spreading in greenhouses.
I have done some search online and found similar cases in the area (I posted the photos that is similar to the case we have).
Please share your opinion.
Thank you,
  • asked a question related to plant pathogens
Question
10 answers
I have isolated recently pathogenic for tomato plant bacteria of Chryseobacterium sp. There is a few references about such bacteria as plant pathogens, including one old strain NCPPB No.  583 of Chryseobacterium sp. received as Xanthomonas stizolobiicola from India and isolated from Stizolobium deeringianum (legumes).
Is there any other records of plant pathogenic Chryseobacterium sp.?
Relevant answer
I had a sample with initial wilt symptoms, with adventicious roots. Later other planta oficina greenhouse tomatodo shoun symptoms as P. corrugata. But the molecular taxonómica report with Sequence of 16S tell me that the bacteria is included in Chryseobacterium genera.
  • asked a question related to plant pathogens
Question
1 answer
It is known that L glucose cannot be used by living organisms as a source of energy because it cannot be phosphorylated by hexokinase, the first enzyme in the glycolysis pathway. One of the known exceptions is in Burkholderia caryophylli, a plant pathogenic bacterium, which contains the enzyme D-threo-aldose 1-dehydrogenase which is capable of oxidizing L-glucose.
So, suppose that we inject L glucose in the stem of a certain plant, What is its fate?
Relevant answer
Answer
Co2 ad H2O
  • asked a question related to plant pathogens
Question
1 answer
As you know GWAS have become very popular for finding causal variants using natural populations, then why there is a huge discrepancy between the number of GWAS done on hosts (wheat, maize, rice etc) and pathogens (fungi, bacteria)?
There are numerous GWAS paper for different traits in agricultural crops, but very few for identifying pathogen virulence genes or loci.
What are the possible reasons?
Thanks.
Relevant answer
Answer
Genome-wide association study (GWAS) is known to be the best population genomic approach to identify genomic regions associated with traits using natural populations. However, applying this method is based on the laboratory infrastructure, therefore scientists looking for an alternative simple approach to achieve their research goals.
  • asked a question related to plant pathogens
Question
14 answers
Hi
The inhibition of spore germination and growth of Botrytis cinerea upon treatment with toxic molecule occured on solid culture medium (petri dishes) as predicted before. Strikingly, the spores germinated normally in liquid medium that contain also the toxic molecule at the same concentration (flasks).
How can we explain such observation??
(See attached pic.)
Relevant answer
Answer
I know there are metabolic pathway shifts in fungi when they are grown under those two conditions. The fungi may be inhibiting uptake of the inhibitor, inactivating the inhibitor or may just be insensitive to it under growing conditions as a submerged culture.
  • asked a question related to plant pathogens
Question
5 answers
Dear all. It is known, that climate change and also extreme weather can cause outbreak of some pests and their enemies also. Other pests may be diminshed. The question is: How extreme weather events like heat, drought, storm, heavy down poors, hail, flooding will influence the special diseases of meadow fescue and the special plant protection measures (chemical and biological) in meadow fescue. We found nothing in literature but need more information for risk assessment. Under current climate conditions plant diseases and pests, (mammalians, weeds, insect pests, nematodes and plant pathogens like fungi, viruses, bacteria) can cause considerably yield losses and damages of crops. Climate change will likely lead to increase the frequency, intensity, spatial extent, duration and timing of weather and climate extremes. Does anyone have any information about the impacts of extreme weather events on diseases and pests of meadow fescue? We reviewed the possible impacts of weather extremes on pests (weeds, insect pests and plant pathogens) of meadow fescue by analyzing scientific literature published since 1945, concerning the knowledge about the influences of extreme weather on incidence of these pests.
Relevant answer
Answer
Dear Seidal,
As you know from your searches, a limited amount of information on the potential impacts of climate change on plant harmful organisms is available. It is known that extreme changes of climate affect plants in natural and agroecological conditions throughout the world. These changes directly impact plants and their interactions with harmful organisms. In addition, there is clear evidence that climate change is altering the distribution of plant harmful organisms, but the full effects are difficult to predict and need to be assessed on a case by case basis. From my point of view, extreme climate changes will affect pests, yield and quality of meadow fescue. The prediction is that extraordinary weather conditions may alter rates of pest development, affect host resistance and lead to changes in the physiology of host - pest interactions of meadow fescue. However, can’t say that how much this conversion will realize. It needs to be studied.
Good luck
  • asked a question related to plant pathogens
Question
14 answers
How can we determine which pathogen (bacteria, fungi, virus) is responsible for a given plant disease from a phenotypic observation (for example: spots, smudges on leaves) ??
Relevant answer
Answer
All instrumental methods can be applied for the pathogen identification (microscopic analysis, wet chamber, pure culture isolation, artificial inoculation tests, biochemical tests like LOPAT for Pseudomonas, ELISA, FAME, PCR, LAMP, DNA sequencing, MALDI), but they are quite far from the simple phenotypic observation.
  • asked a question related to plant pathogens
Question
4 answers
Dear all. It is known, that climate change and also extreme weather can influence the outbreak of some pests and their enemies also. Other pests may be diminshed. The question is: How extreme weather events like heat, drought, storm, heavy down poors, hail, flooding will influence the special diseases of alfalfa and clover and the special plant protection measures (chemical and biological) in clover and alfalfa. We found nothing in literature but need more information for risk assessment. Under current climate conditions plant diseases and pests, (mammalians, weeds, insect pests, nematodes and plant pathogens like fungi, viruses, bacteria) can cause considerably yield losses and damages of crops. Climate change will likely lead to increase the frequency, intensity, spatial extent, duration and timing of weather and climate extremes. Does anyone have any information about the impacts of extreme weather events on diseases and pests of rye grasses? We reviewed the possible impacts of weather extremes on pests (weeds, insect pests and plant pathogens) of hop by analyzing scientific literature published since 1945, concerning the knowledge about the influences of extreme weather on incidence of these pests.
Relevant answer
Answer
Dear Dr. Petra Seidel,
Please check the following link.
Good luck!
  • asked a question related to plant pathogens
Question
5 answers
We are using the Voges-Proskauer test to differentiate plant pathogenic Enterobacteria (we are using the Rosco Diatab system). Most protocols recommend incubating the cultures at 35-37°C for 48h to produce a dense suspension for the test. Diatabs also recommends incubating at 35-37°C before Barritt’s Reagents A and B are added. I wonder whether the temperature recommendation is because many Enterobacteria are from clinical samples (and so this is likely their optimum growth temperature), or this temperature is needed for the test itself. In other words: do we need to incubate Pectobacterium/ Erwinia etc. at 35-37°C, or at their optimum growth temperature which is of course much lower?
Relevant answer
Answer
Thanks for the answers.
Meanwhile I have tried at two temperatures: 28 and 36/37°: both my plant associated Erwinia isolates were clearly positive at both temperatures (as expected from literature data), while another (Pectobacterium) was negative. Obviously, it works at both 28 and 37°.
@ Krishna Rayudu,
VP test is a common test to discriminate plant associated enterobacteria, in particular Erwinia spp.
  • asked a question related to plant pathogens
Question
2 answers
Is fingerprinting method standard method to identify type of fungal plant pathogen and if it is how can I apply it?
Relevant answer
Answer
Rapid and reliable DNA extraction and PCR fingerprinting methods to discriminate multiple biotypes of the nematophagous fungus Pochonia chlamydosporia isolated from plant rhizospheres
December 2008Letters in Applied Microbiology 48(1):71-6
DOI10.1111/j.1472-765X.2008.02489.x
Rosa Helena Manzanilla LopezRosa Helena Manzanilla LopezIan Michael ClarkIan Michael ClarkS.D. Atkins
  • asked a question related to plant pathogens
Question
6 answers
Hi there,
I'm studying changes in frequencies of approximately 40-50 SNP alleles in nine regions across a country within a gene of interest in a plant pathogen. to gather this data a large number of samples have been taken from each of the nine sites for six sequential years, and illumina sequenced in a pool. so I will have nine .bam and .vcf files with around a hundred reads (high coverage) each, giving me a number analogous to allele frequency for each snp, for each site, in each year.
I am trying to determine an appropriate statistical analysis for detecting significant changes in allele frequency across this six year time frame. so far I think a CMH-test (probably using the r package popoolation2) will be my best option, with year and allele frequency as the nominal variables, and sites as replicates. however I'm conscious of heterogeneity between sites, which given my previous results is unlikely, but possible.
Would anyone be able to give me any other options? I was also thinking of a GLM with bonferroni correction, but cannot find a convenient way of implementing this with a six leveled qualitative independent variable.
Relevant answer
Answer
Following
  • asked a question related to plant pathogens
Question
6 answers
What are the potential effects of on interactions between nonvectors and vectors on the spread of plant pathogens in managed and natural ecosystems?
Previous studies have shown that different herbivore and plant pathogen species elicit different hormone responses in plants.
Mediated by plant defenses, could herbivores and plant pathogens interact to affect the spread of the disease across landscapes?
Any thoughts?
Relevant answer
Answer
Hi Juan, Alex and Bertrand,
First of all, thank you all so much for your valued feedback and suggestions on the proposed subject. I agree that this is indeed a very complex and interesting question to be asked.
And these fairly complex answers (studies) address just one aspect of by far more complex interactions in managed systems. timing of hormones produced (i.e., salicylic acid [SA] stimulates compounds targeting pathogens and jasmonic acid [JA] tends to produce compounds targeting insects) and further, in some plants, the production of one (SA or JA) inhibits production of the other as shown by Thaler et al. (2010). Also a more recent preliminary work by Chisholm et al. (2014) showed that Pea enation Mosaic Virus indirectly promotes aphid (Acyrthosiphon pisum; vectors) fitness by suppressing plant defenses and that Pea leaf weevil (Sitona lineatus; non vector generlists) indirectly benefits aphid (Acyrthosiphon pisum; vectors) behavior by increasing plant palatability.
And these fairly complex answers (studies) address just one aspect of these by far more complex interactions in managed systems.
Looking at the effects of soil environment in managed systems adds another dimension to it. Thanks for sharing your research Juan!
As Alex mentioned, what about natural ecosystems which are by far more robust and more complex?
For sure, I agree that the question of pathology of a specific type of pathogen spreading across the biotope is complex, and needs a multidisciplinary approach. Thanks Bertrand!
Thanks!
Ivan
Credits:
Thaler, J.S., Agrawal, A.A. and Halitschke, R., 2010. Salicylate‐mediated interactions between pathogens and herbivores. Ecology, 91(4), pp.1075-1082.
Chisholm, P., Eigenbrode, S.D., Crowder, D. 2014. Can non-vector herbivores suppress the spread of a plant virus? Annual Meeting Entomological Society of America, Nov. 20

  • asked a question related to plant pathogens
Question
11 answers
I want to enhance the basal resistance of tomato to pathogen (fungi). So I was hoping i could get a methodology for elucidating the molecular mechanism of epidermal specification and maintanace as it relates to basal resistance to fungal plant pathogen
  • asked a question related to plant pathogens
Question
3 answers
I was going to order short peptides 20-30AA conjugated to KLH to immunize a rabbit for antibodies against a plant pathogen.
Fortunately i stumbled across this article which reports KLH-antibodies cross reacting with plant proteins. https://www.ncbi.nlm.nih.gov/pubmed/18992832
It also claims " Polyclonal antisera from herbivorous animals, such as rabbits and chicken, often display non-specific background
reaction towards plant antigens, while rat antisera usually exhibit minimal such cross-reactivity. "
but in our experience with rabbits this has never happened, do you believe rats are actually a better option?
Back to main issue, i do not want to perform affinity chromatography to purify my peptide specific antibodies.Would cross absorption with KLH do the trick?
Alternatively, could you recommend another carrier protein that is as good as KLH in inducing an immune response without the cross reactivity with plant antigens?
Many thanks :)
Relevant answer
Answer
I agree with John that BSA is a very good carrier molecule for this purpose. It also has the advantage that peptide conjugation can easily monitored by MALDI-MS.
From my point of view, affinity chromatography with the peptide would be the best option in most cases, particularly in the context of complex samples. Many companies offering custom antibodies purify the antibodies this way, if the peptide is available. Cross-adsorption on KLH would might be beneficial, but leaves all other cross-reacting antibodies in the serum. It only helps, if you can track down your problem definitely on the KLH issue.
  • asked a question related to plant pathogens
Question
13 answers
We have a task for water samples analysis and need to concentrate /isolate all groups of plant pathogens separately for PCR from the same sample. So far, we apply 3 rounds of filtration. Is there any other options?
Relevant answer
Answer
Hi Alex! For Phytophthora ramorum, water was filtered through a Buchner funnel with Whatman filter paper and the filter was then plated on selective medium. The medium would only select for oomycetes, however. The filter paper could also be tested by PCR to test for whatever organisms you desired.
  • asked a question related to plant pathogens
Question
2 answers
hello every one,
I am working on soil born pathogen like Fusarium , i want to coat seeds with nano particles to control disease of chickpea and other economically crop. please guide me it possible or not ? if possible then please guide me to procedure for coating
.
Relevant answer
Answer
Hello
Please have a look at pdf attachments.
Good luck!
  • asked a question related to plant pathogens
Question
22 answers
Dear Colleagues
I am interested to use secondary metabolites of trichoderma to enhance plant growth and to control plant pathogens. So How may I isolate cerinolactone from broth culture and whats the function of it on plant body can anyone explain?
Regards
Shuvrah
Relevant answer
Answer
Good Luck
  • asked a question related to plant pathogens
Question
4 answers
i search for standard method to study antifungal effect of plant extracts on plant pathogenic fungi
Relevant answer
Answer
Plant pathogenic fungi will behave any other fungi. So there are no special culture conditions for plant pathogenic fungi. You can follow the usual procedure followed for studying the antifungal activity of extracts. NCCLS broth dilution methods are considered to be standard for studying anti-bacterial or anti-fungal activity. If you want to publish in an international journal your work, you must follow NCCLS method.
Wish you all the best.
  • asked a question related to plant pathogens
Question
2 answers
Sir, i m working on Myco-synthesis of silver nanoparticles against some plant pathogenic fungi. i want to know about the characterization of them .. in which form(like powder or liquid) and if we want to apply it in field how we should use them ?
Relevant answer
Answer
You have done myco-synthesis, therefore, I hope your particles are in liquid form. For characterization, I suggest, first you go for Particle Size Analysis ( Dynamic light scattering ) that you can do directly in liquid form and it will provide you the size distribution of your particle. Generally the instrument also attached to Zeta Potential which may provide the information about the stability of your particle. Then you may go for TEM, it is a microscopy technique, where you need powder sample. For that you can Ultra-Centrifuge your samples. Preparation of TEM specimens is specific to the materials under analysis. TEM may measure the three dimensional size of your particle. After that you may go for SEM, where also you need completely hard dry material. Your biological sample should be fixed chemically for that purpose. SEM will provide you information of the exact shape of your particle. The other instrument normally used for nano-particle characterization are UV-VIS, FTIR, AFM etc.
  • asked a question related to plant pathogens
Question
3 answers
I was analyzing several examples of plant pathogen interaction (pathosystems) and I was wondering if cell expansion comes first or second to cell division. Of course, I must considered that everything happens after a PAMP sequence of events and also to possible recognition of pathogen by plant cells.
Does anybody have some clues?
Thanks and Regards,
Dr. Joao Paulo R. Marques
Relevant answer
Answer
Actually, the question is very general. As far as, i have understood, the phenomenon of cell division or expansion is highly specific to individual plant-pathogen interactions. Some pathogens suppress cell division (for example, using CLE effectors) to colonize the host, whereas some pathogens modulate hosts' hormonal pathways and induce cell division (for example using AvrPtoB, TAL class effectors, etc.). Therefore, the process of cell division or cell expansion is highly controlled by the presence of certain types of effectors, metabolites and receptors of both pathogen and its host and also depends on the spatial (tissue) conformations, where the interaction is happening.
  • asked a question related to plant pathogens
Question
6 answers
I need information about this phenomenon on breeding crops of any disease. Please any job or publication you could share with me would be very useful.
Thank you so much.
Relevant answer
Answer
Dear Laura,
In my understanding, the correlation between inoculum concentration and disease symptoms might occur. However, such correlation cannot be modeled because this pattern is occasional considering the following: (i) occurrence and severity of symptoms depend on many other factors, not only the concentration of inoculum; (ii) varying the concentration, you may found variations in symptoms in association with the inhibition effect; and (iii) this variation may also occur differently for different plant pathogens in the same experimental conditions.
Kind regards
  • asked a question related to plant pathogens
Question
8 answers
Hello, I want to preserve wheat blast fungus in glycerol for long term storage. However, I do not know the procedure for this particular fungus. What should be the concentration of glycerol? Do I need to make conidial suspension and then store it? or What is the whole procedure? please give me some suggestions.
Relevant answer
  • asked a question related to plant pathogens
Question
4 answers
Hello
Trichoderma has reached substantial success as a influential biocontrol agent at worldwide level, it is necessary to understand the mechanisms of action of Trichoderma harzianum against plant pathogenic fungi that could highlight to the target specific secondary metabolites of antagonistic fungi for suppressing plant pathogenic fungi.
Relevant answer
Answer
You most welcome
Houda
  • asked a question related to plant pathogens
Question
9 answers
could you please tell me what the problem is?
Relevant answer
Answer
thanks for your follow 
  • asked a question related to plant pathogens
Question
4 answers
Assalam-u-Alaikum!
For my research work I need "POTATO VIRUS X (PVX)". Please if some one provide me Potato Virus X infected plants.
Thanks in anticipation.
Relevant answer
Answer
you most welcome
Houda
  • asked a question related to plant pathogens
Question
1 answer
Confrontation assay is usually conducted between a bacteria and plant pathogen but is there any method of checking this assay between plant and bacteria?
Relevant answer
Answer
You can use confrontation in agar method