Bacterial Pathogens: Epiphytes and Endophytes in Seeds
Epiphytes and Endophytes in Seeds
Bacterial Pathogens: Epiphytes and Endophytes in Seeds
Bacterial pathogens have been known to exist as epiphytes on the surface of plant seeds, and also as endophytes within the seeds themselves. The ability of bacterial pathogens to survive outside of the plant seed and within it can be attributed to various mechanisms, such as the production of protective exopolysaccharides and the ability to form biofilms.
According to Hagen et al. (2013), bacterial epiphytes can survive on the surface of plant seeds by forming biofilms, which provide protection from environmental stresses and predation by other microorganisms. Biofilms are complex structures that allow bacterial cells to adhere to a surface and form a protective layer of extracellular polymeric substances (EPS). The EPS matrix provides a barrier against desiccation, nutrient limitation, and other environmental stresses, allowing the bacterial cells to survive for extended periods on the seed surface.
Additionally, bacterial endophytes can survive within plant seeds by utilizing various strategies, such as the production of exopolysaccharides that protect the bacterial cells from desiccation and provide a source of nutrients (Soto et al., 2019). These exopolysaccharides can also promote the establishment of a symbiotic relationship between the bacteria and the seed, allowing the bacteria to remain within the seed and potentially infect the developing plant.
Furthermore, bacterial endophytes can also enter the plant seed through wounds or natural openings, such as stomata or lenticels (Berg et al., 2017). Once inside the seed, the bacteria can establish a niche within the seed tissues and persist until the seed germinates and the plant develops.
In conclusion, bacterial pathogens can survive as epiphytes on the surface of plant seeds and as endophytes within the seeds themselves. This ability is attributed to various mechanisms, including the production of protective exopolysaccharides and the ability to form biofilms. These mechanisms enable the bacteria to persist in the environment and potentially infect the developing plant.
Danger of plant pathogens in seeds for indoor cultivation
Seeds can bring pathogens to Indoor Grows
Plant pathogens in seeds can have a significant impact on indoor-grown food crops, causing widespread destruction if not managed effectively.
These organisms can quickly spread and infect entire crops, resulting in devastating economic losses.
The speed at which these pathogens can spread and cause damage depends on various factors such as the type of pathogen, the environmental conditions, and the crop's susceptibility to the disease.
This report examines the impact of plant pathogens on indoor-grown food crops and provides recommendations for managing and mitigating the risks associated with these pathogens.
Indoor-grown food crops are becoming increasingly popular due to their ability to grow in controlled environments and reduce the risks associated with traditional outdoor farming.
However, these crops are still vulnerable to plant pathogens that can spread rapidly and cause extensive damage if not managed effectively.
Plant pathogens in seeds, for example, can infect the crop early in its life cycle, making it difficult to control and manage the disease.
Impact of plant pathogens
Plant pathogens in seeds can spread rapidly and cause significant damage to indoor-grown food crops. For example, Fusarium oxysporum is a fungal pathogen that can infect the roots of tomato plants, causing wilt and ultimately killing the plant.
This pathogen can spread quickly through contaminated soil, water, and equipment, making it difficult to control.
The Pythium pathogen, can cause damping-off, root rot, and stem rot in various indoor-grown crops such as lettuce, spinach, and basil. This pathogen can spread through soil, water, and plant debris, making it difficult to manage and control.
Speed of pathogen spread
The speed at which plant pathogens in seeds can destroy indoor-grown food crops depends on various factors such as the type of pathogen, the environmental conditions, and the crop's susceptibility to the disease.
Fusarium spp. can destroy an entire crop within weeks if not managed effectively.
Similarly, environmental conditions such as temperature, humidity, and light can also impact the speed of pathogen spread. High humidity, for example, can create a favorable environment for pathogens to thrive, leading to faster disease development and spread.
Detection and Mitigation
To mitigate the risks associated with plant pathogens in seeds, it is essential to implement effective detection measures such as requiring only disease-tested seeds, practicing proper sanitation, and implementing an integrated pest management (IPM) program.
Using only disease-tested seeds is one of the most effective ways to reduce the risk of plant pathogen transmission.
Seeds can be tested for various pathogens prior to shipment, upon receipt, and before planting, ensuring that only disease-free (tested) seeds are used at the facility.
Request a Certificate of Analysis (CoA) from the seed vendor and test the seeds upon receipt.
Engage an in-house testing laboratory to exercise extreme caution so as to prevent good resources raising a contaminated crop.
These precautions help mitigate the risk.
Effects of Plant Pathogens
A study by Savary et al. (2019) found that plant diseases can reduce global crop yields by up to 15%, resulting in a loss of around $220 billion per year. In indoor farming, where crops are grown in a controlled environment, the loss can be even higher due to the significant investment in equipment, lighting, and energy costs. Therefore, it is essential to take preventive measures to protect your indoor-grown food crop from plant pathogens.
Crop Rotation
Crop rotation is another effective preventive measure that can help reduce the risk of plant pathogens. This involves growing different crops in the same space to reduce the buildup of soil-borne pathogens that can infect the same crop over time.
Treatment Options
Despite preventive measures, plant pathogens may still infect indoor-grown food crops. In such cases, treatment options such as biological control, chemical control, and cultural control can be effective.
Biological control involves the use of natural enemies of the pathogen, such as predators, parasites, or pathogens that feed on the plant pathogen.
Chemical control involves the use of fungicides, bactericides, or virucides to kill the pathogen.
Cultural control involves modifying the growing environment or crop management practices to reduce the spread of the pathogen.
Sanitation Practices
Proper sanitation practices can also prevent the spread of plant pathogens in indoor farming.
This includes cleaning and disinfecting equipment, tools, and surfaces regularly, as well as maintaining proper air circulation and humidity levels in the growing environment.
An Integrated Pest Management (IPM) program should include cultural, physical, and biological control measures which can also help manage and control plant pathogens in seeds.
Summay
Plant pathogens in seeds can have a significant impact on indoor-grown food crops, causing widespread destruction if not managed effectively.
The speed at which these pathogens can spread and cause damage depends on various factors such as the type of pathogen, the environmental conditions, and the crop's susceptibility to the disease. Implementing effective control measures such as using disease-free seeds, practicing proper sanitation, and implementing an IPM program can help mitigate the risks associated with plant pathogens in seeds.493
SEED SAMPLE PREPARATION FOR ENDOPHYTES IN SEEDS
Seed Sample Preparation Prior to qRT-PCR Testing
Endophytes are microorganisms that live within plant tissues without causing apparent harm to their hosts.
Endophytic microorganisms have been found in various plant parts, including seeds, where they play a crucial role in plant growth, development, and defense mechanisms (Gouda et al., 2016). Studying endophytes in seeds requires proper seed sample preparation to avoid contamination and ensure the accuracy of the results.
This scientific article describes the seed sample preparation methods for endophytes in seeds, including surface sterilization, aseptic techniques, and molecular identification. The article also discusses the advantages and limitations of each method.
Surface Sterilization
Surface sterilization is a crucial step in seed sample preparation for endophytes in seeds.
The objective of surface sterilization is to eliminate the external microbial population without harming the internal endophytic microorganisms.
The most commonly used method for surface sterilization is the combination of ethanol and sodium hypochlorite.
The seeds are soaked in 70% ethanol for 30 seconds, followed by 2-4% sodium hypochlorite for 2-10 minutes, depending on the seed's surface structure (Suryanarayanan et al., 2016).
The sterilized seeds are then washed with sterile distilled water to remove any residual chemicals.
Aseptic Techniques
After surface sterilization, aseptic techniques are used to prevent recontamination of the seeds. Aseptic techniques involve working in a sterile environment, using sterile equipment and materials, and handling the seeds with sterile forceps.
The seeds are then placed on sterile Petri dishes containing nutrient agar or other suitable growth media. The plates are then incubated at the appropriate temperature and humidity for the specific endophyte being studied (Yuan et al., 2018).
Molecular Identification
Molecular identification techniques are used to identify the endophytes in seeds. These techniques involve DNA extraction, amplification, and sequencing of the endophytic DNA. DNA extraction involves breaking open the cells to release the DNA, followed by purification to remove any impurities.
The purified DNA is then amplified using polymerase chain reaction (PCR) with primers specific to the target endophytic DNA. The amplified DNA is then sequenced and compared to DNA databases to identify the endophytic species (Gouda et al., 2016).
Advantages and Limitations
Surface sterilization is an effective method for eliminating external microbial populations, but it may harm the internal endophytic microorganisms if not done correctly.
Aseptic techniques ensure the seeds remain sterile, but they require specialized equipment and a sterile environment, making them time-consuming and expensive.
Molecular identification provides accurate identification of endophytic species, but it requires specialized expertise, equipment, and reagents, making it expensive and time-consuming (Suryanarayanan et al., 2016).
Summary
Seed sample preparation for endophytes in seeds requires careful attention to avoid contamination and ensure the accuracy of the results. Surface sterilization, aseptic techniques, and molecular identification are the three main methods used for seed sample preparation.
Surface sterilization is an essential step in seed sample preparation, and it is commonly used to eliminate the external microbial population without harming the internal endophytic microorganisms.
Aseptic techniques are used to prevent recontamination of the seeds and require working in a sterile environment and handling the seeds with sterile forceps.
Molecular identification provides accurate identification of endophytic species and involves DNA extraction, amplification, and sequencing.
Molecular identification provides accurate identification of endophytic species but requires specialized expertise, equipment, and reagents, making it expensive and time-consuming.
Proper seed sample preparation for endophytes in seeds is crucial for obtaining accurate and reliable results.Each method has its advantages and limitations.
Surface sterilization is effective but may harm the internal endophytic microorganisms if not done correctly.
Aseptic techniques ensure seed sterility but require specialized equipment and a sterile environment, making them time-consuming and expensive.
The selection of the appropriate method depends on the specific research objectives, available resources, and expertise.
Researchers must carefully consider the advantages and limitations of each method to select the most suitable approach for their research.
It is also essential to note that the quality of the seed sample is critical for the success of the research.
Seed samples should be collected from healthy plants, free from disease, and harvested at the appropriate time.
Proper storage of the seed samples is also crucial to maintain their viability and avoid contamination.
Furthermore, the selection of the appropriate growth media is crucial for the successful isolation of endophytes.
Different endophytic species have different nutritional requirements, and therefore, selecting the appropriate growth media is necessary for the successful isolation and identification of endophytes.
Endophytes are essential components of the plant microbiome and have enormous potential for agriculture and biotechnology applications.
Endophytic microorganisms have been shown to enhance plant growth, improve nutrient uptake, and confer resistance to abiotic and biotic stresses.
Therefore, studying endophytes in seeds is essential for understanding their role in plant growth, development, and defense mechanisms.
Seed sample preparation is a crucial step in studying endophytes in seeds. Researchers must carefully consider the advantages and limitations of each method and select the most appropriate approach for their research.
The quality of the seed sample, selection of the appropriate growth media, and understanding the role of endophytes in plant growth and development are essential for the success of the research and its potential applications in agriculture and biotechnology.
reducing or eliminating the pathogens in seeds
Seed Sanitation Methods
Seed sanitation is the process of reducing or eliminating the pathogens present on the surface of seeds. The goal is to prevent the spread of plant diseases that can result in reduced crop yields and economic losses for farmers. There are several methods of seed sanitation that can be used to kill pathogens on the surface of seeds, including:
Heat treatment: Seeds can be treated with high temperatures to kill pathogens. This can be done using a dry heat method or by using steam.
Chemical treatment: Seeds can be treated with chemicals to kill pathogens. Some commonly used chemicals include sodium hypochlorite (bleach) and hydrogen peroxide.
Irradiation: Seeds can be treated with radiation to kill pathogens. This method is effective but is not widely used due to concerns about the safety of irradiated food.
Biological control: This involves the use of beneficial microorganisms to suppress plant pathogens. This method is often used in combination with other methods to improve seed sanitation.
Regardless of the method used, it is important to follow proper safety precautions when handling and treating seeds. This includes wearing protective gear, following recommended application rates and times, and properly disposing of any waste materials.
seed sanitization methods
Chemical treatment
AME Cold Fusion Seed Sanitization
AME Cold Fusion Seed Sanitization
Seed treatment with specific concentrations of Peracetic acid prior to planting
AME Cold Fusion Seed Sanitization
AME Cold Fusion Seed Sanitization
AME Cold Fusion Seed Sanitization
Benchtop seed sanitization system for seed according to FDA FSMA standards (J. Fungi 2021, 7, 650.
Seed Surface Disinfection
AME Cold Fusion Seed Sanitization
Seed Surface Disinfection
The AME seed surface disinfection system reduces the relative CFU formation with non-thermal plasma
treatment thus reducing human and plant pathogens on the seed surfaces (crop science, vol. 54, march–april 2014 )
AME-developed seed sanitation system
Pre-Planting Seed Sanitization:
Seed sanitization via chemical processes removes/reduces microbes from the external surfaces of the seed and thereby could have an impact on the plants’ health or productivity.
Pre-planting seed sanitizing methods can be engaged to prevent seed-borne human and plant pathogens and diseases, especially those caused by bacteria and viruses infecting the surfaces of the seeds.
The objective is to:
• Minimize the potential risks of the pathogens infecting the new plant growth
• Prevent bacterial pathogens (E. coli, Salmonella, Listeria) from cross-contamination
• Prevent yeasts and molds, and plant pathogens
--Pythium
--Pseudomonas
--Fusarium
--Rhizoctonia
• All seed sanitization methods should sanitize while maintaining the life force of the seeds
Announcement from the USDA
USDA new guidelines affirm DNA-based testing for 99% Salmonella free Chicken.