Saccharomycotina
•
0 likes•76 views
Yeasts such as Saccharomyces (budding yeast) and Schizosaccharomyces (fission yeast) belong to the group Saccharomycotina. They reproduce asexually through budding, conidia, or fission and do not produce ascospores or ascogenous hyphae.
Report
Share
Report
Share
Download to read offline
Recommended
Morphology of bacteria
Bacteria are unicellular, prokaryotic microorganisms that reproduce through binary fission. Most plant pathogenic bacteria are rod-shaped, between 0.5-5.0 μm in size, and gram-negative. Bacteria shapes include: cocci (spherical), bacillus (rod-shaped), and spirillum (spiral or curved rods). The main shapes of cocci are mono coccus, diplo coccus, streptococcus, staphylococcus, and sarcina. Bacillus can be straight rods occurring singly, in pairs, chains, or parallel arrangements. Spirillum include vibrio (curved rods), spirillum (rigid spirals), and spiroche
CRISPR PPT.pptx
This document provides an overview of the CRISPR-Cas system including its history, mechanisms, types, applications in plant pathology, and use for genome editing. Some key points covered include:
- CRISPR-Cas is an adaptive immune system found in bacteria that provides resistance to viruses. It was discovered in 1987 and its mechanism of targeting invading DNA was determined in 2005.
- There are six types of CRISPR-Cas systems classified by their effector proteins. Type II uses Cas9 protein and is commonly used for genome editing.
- The CRISPR-Cas9 system involves crRNA guiding Cas9 to cleave invading DNA at specific locations. This has enabled powerful applications like knocking out genes
1. Diseases of rice
This document summarizes 15 important diseases that affect rice, including their causal organisms, symptoms, modes of spread, survival methods, and management strategies. The major fungal diseases discussed are blast, brown spot, sheath blight, sheath rot, and stem rot. The major bacterial diseases are bacterial leaf blight and bacterial leaf streak. Viral diseases covered include tungro, grassy stunt, rice dwarf, and yellow dwarf. Other diseases summarized are false smut, udbatta disease, grain discoloration, and rice khaira deficiency. For each disease, the summary provides key details about identification and control.
Breeding for quality traits (protein,oil)
This document discusses breeding crops for improved quality traits like protein and oil content. It covers topics like:
- Quality traits can be morphological, organoleptic, nutritional, or biological.
- Protein efficiency ratio and biological value are measures of protein quality in foods.
- Breeding maize with higher lysine and tryptophan content led to the development of Quality Protein Maize varieties.
- A case study describes using in vitro mutagenesis and selection with hydroxyproline to develop peanut varieties with over 55% oil content in kernels.
- Breeding objectives for sunflower include seed yield, oil content, and modifying oil quality traits like fatty acid composition.
Artifial intellegence in Plant diseases detection and diagnosis
1) Artificial intelligence can help detect and identify plant diseases by analyzing images of infected plants. Advanced techniques like machine learning and deep learning are being used for accurate disease identification.
2) IoT sensors are being used to monitor crop health and send data to the cloud for analysis. This allows early detection of diseases.
3) While AI has benefits like precision and speed, challenges remain in applying these new technologies at large scale in agriculture due to lack of familiarity, data and infrastructure requirements, and uncertainty around external growing conditions.
Towards managing of soil borne plant pathogens in India
Managing soil-borne plant pathogens by means of biological agents is become widely popular and practical nowadays to avoid getting problems from synthetic control measures, this ppt clear describes various important bioagents in the management of soil-borne plant pathogens
CRISPR, cas9 in plant disease resistance
CRISPR/Cas9 is an advanced genome editing technology that can be used to develop plant disease resistance. It involves a Cas9 enzyme that acts like molecular scissors to cut DNA at specific locations guided by CRISPR RNA. This triggers DNA repair that can introduce changes to genes. Researchers have used CRISPR/Cas9 to develop resistance in plants against viruses, fungi, and bacteria by editing genes involved in host-pathogen interaction and disease susceptibility. It provides a precise and efficient way to edit plant genomes to improve crop resistance compared to previous tools. Scientists continue working to enhance the specificity and control of CRISPR/Cas9 for genome editing applications in agriculture.
Biosensors in plant pathogen detection
Biosensors in plant pathogen detection is one of the recent advancements in plant pathology for the detection of plant pathogens
Recommended
Morphology of bacteria
Bacteria are unicellular, prokaryotic microorganisms that reproduce through binary fission. Most plant pathogenic bacteria are rod-shaped, between 0.5-5.0 μm in size, and gram-negative. Bacteria shapes include: cocci (spherical), bacillus (rod-shaped), and spirillum (spiral or curved rods). The main shapes of cocci are mono coccus, diplo coccus, streptococcus, staphylococcus, and sarcina. Bacillus can be straight rods occurring singly, in pairs, chains, or parallel arrangements. Spirillum include vibrio (curved rods), spirillum (rigid spirals), and spiroche
CRISPR PPT.pptx
This document provides an overview of the CRISPR-Cas system including its history, mechanisms, types, applications in plant pathology, and use for genome editing. Some key points covered include:
- CRISPR-Cas is an adaptive immune system found in bacteria that provides resistance to viruses. It was discovered in 1987 and its mechanism of targeting invading DNA was determined in 2005.
- There are six types of CRISPR-Cas systems classified by their effector proteins. Type II uses Cas9 protein and is commonly used for genome editing.
- The CRISPR-Cas9 system involves crRNA guiding Cas9 to cleave invading DNA at specific locations. This has enabled powerful applications like knocking out genes
1. Diseases of rice
This document summarizes 15 important diseases that affect rice, including their causal organisms, symptoms, modes of spread, survival methods, and management strategies. The major fungal diseases discussed are blast, brown spot, sheath blight, sheath rot, and stem rot. The major bacterial diseases are bacterial leaf blight and bacterial leaf streak. Viral diseases covered include tungro, grassy stunt, rice dwarf, and yellow dwarf. Other diseases summarized are false smut, udbatta disease, grain discoloration, and rice khaira deficiency. For each disease, the summary provides key details about identification and control.
Breeding for quality traits (protein,oil)
This document discusses breeding crops for improved quality traits like protein and oil content. It covers topics like:
- Quality traits can be morphological, organoleptic, nutritional, or biological.
- Protein efficiency ratio and biological value are measures of protein quality in foods.
- Breeding maize with higher lysine and tryptophan content led to the development of Quality Protein Maize varieties.
- A case study describes using in vitro mutagenesis and selection with hydroxyproline to develop peanut varieties with over 55% oil content in kernels.
- Breeding objectives for sunflower include seed yield, oil content, and modifying oil quality traits like fatty acid composition.
Artifial intellegence in Plant diseases detection and diagnosis
1) Artificial intelligence can help detect and identify plant diseases by analyzing images of infected plants. Advanced techniques like machine learning and deep learning are being used for accurate disease identification.
2) IoT sensors are being used to monitor crop health and send data to the cloud for analysis. This allows early detection of diseases.
3) While AI has benefits like precision and speed, challenges remain in applying these new technologies at large scale in agriculture due to lack of familiarity, data and infrastructure requirements, and uncertainty around external growing conditions.
Towards managing of soil borne plant pathogens in India
Managing soil-borne plant pathogens by means of biological agents is become widely popular and practical nowadays to avoid getting problems from synthetic control measures, this ppt clear describes various important bioagents in the management of soil-borne plant pathogens
CRISPR, cas9 in plant disease resistance
CRISPR/Cas9 is an advanced genome editing technology that can be used to develop plant disease resistance. It involves a Cas9 enzyme that acts like molecular scissors to cut DNA at specific locations guided by CRISPR RNA. This triggers DNA repair that can introduce changes to genes. Researchers have used CRISPR/Cas9 to develop resistance in plants against viruses, fungi, and bacteria by editing genes involved in host-pathogen interaction and disease susceptibility. It provides a precise and efficient way to edit plant genomes to improve crop resistance compared to previous tools. Scientists continue working to enhance the specificity and control of CRISPR/Cas9 for genome editing applications in agriculture.
Biosensors in plant pathogen detection
Biosensors in plant pathogen detection is one of the recent advancements in plant pathology for the detection of plant pathogens
Phenomic approaches for plant disease detection
This document discusses various phenomic approaches for plant disease detection, including chlorophyll fluorescence imaging, hyperspectral imaging, thermal imaging, and image processing techniques. It provides details on how each approach works, such as using chlorophyll fluorescence to detect changes in photosynthesis before visual disease symptoms appear. The document also discusses the analysis of data collected from these approaches and how they can be used to rapidly screen large numbers of plant varieties for disease resistance and improve over traditional visual ratings.
Role of antimicrobial peptides in plant disease management
It is one of the advanced topics in plant disease management, detailed information about antimicrobial peptides and their role in plant disease management is furnished clearly.
Quarantine regulation and impact of modern detection methods
Detailed descriptions about quarantine and regulations, new laws, and new techniques are using in plant quarantine for the detection of plant pathogens are described
Bacteriophages and prions
This document discusses bacteriophages and prions. It defines bacteriophage as a virus that infects bacteria, and notes their discovery by Twort and d'Herelle. It describes the structure of bacteriophages like T4, including their DNA-containing heads and helical tails. The document outlines the lytic and lysogenic life cycles of bacteriophages and how they can be used to control plant diseases. Finally, it defines prions as infectious particles composed of misfolded protein that can induce normal proteins to take the same misfolded shape, and lists some animal diseases caused by prions.
Cross protection
Cross protection occurs when infection of a plant with a mild or attenuated virus strain protects the plant from later infection by a more severe strain of the same virus. This was first demonstrated in 1929 with tobacco mosaic virus. It has since been used successfully to control diseases caused by citrus tristeza virus and papaya ringspot virus. There are two main mechanisms of cross protection - coat protein-mediated resistance, which involves blocking virus uncoating or replication, and RNA-mediated resistance, where excess mild strain RNA hybridizes to block replication of the challenge virus. While cross protection has proven effective for some diseases, there are also limitations such as yield loss, incomplete protection, and genetic instability of the protector virus.
Production of disease free planting materials
Thermotherapy, tissue culture, chemotherapy, and electrotherapy are methods used to produce disease-free planting materials. Thermotherapy involves growing plants at high temperatures of 30-40°C for 2-3 months to eliminate viruses. Tissue culture techniques like callus culture, meristem tip culture, and protoplast culture can also produce virus-free plants. Chemotherapy uses antiviral chemicals or growth promoters during meristem tip culture. Electrotherapy applies electrical pulses to eliminate viruses. The document provides details on each method and examples of viruses eliminated from crops like banana, potato, and citrus using these approaches.
Anti viral principles
This document discusses antiviral principles (AVP) found in certain plant leaves and extracts. AVPs are compounds that have inhibitory effects against viruses. The document provides details on preparing an AVP extract from sorghum leaves and using it to manage pathogens. It explains that AVP extracts from various plants like sorghum, prosopis, and bougainvillea have been shown to effectively reduce different viruses in crops like groundnuts, tomatoes, and sunflowers. The mechanism of action of AVPs is that they contain proteins that interfere with viral replication and movement between host cells.
Principles of management of virus diseases
This document summarizes conventional and biotechnological approaches for managing viral plant diseases. Conventional approaches include using virus-free planting materials, cultural practices, vector management, heat therapy, meristem tip culture, and barrier crops. Biotechnological approaches involve pathogen-derived resistance through expression of viral coat proteins or RNA interference mechanisms to inhibit viral genes. The document provides examples and details of various conventional and biotechnological techniques for eliminating viruses from infected plants.
Movement of viruses, physiology of virus infected plants
This document summarizes the movement and physiology of virus-infected plants. It discusses three types of virus movement: intracellular, intercellular, and long-distance. Intracellular movement relies on the endoplasmic reticulum and cytoskeleton, while intercellular movement occurs through plasmodesmata connecting adjacent cells. Long-distance movement involves viruses entering the vascular system and moving systemically through the plant. It also examines effects on the infected plant's photosynthesis, respiration, membrane permeability, translocation, and transcription/translation, such as reduced chlorophyll and sucrose content as well as increased respiration and permeability.
Virus infection and replication
Virus infection and replication occurs in several steps:
1. The virus attaches to and enters the host plant cells, usually through wounds caused by vectors like insects or mechanical damage.
2. Once inside the cell, the viral genome is released from its protein coat through uncoating.
3. The viral genome then hijacks the host cell machinery to replicate, transcribe mRNA, and translate proteins.
New viral genomes and capsids are assembled and the mature virions are released to infect new cells.
Origin of viruses and virus strains
This document discusses the origin and evolution of viruses. It begins by defining key terms like isolate, variant, and strain. It then presents three main hypotheses for the origin of viruses: 1) the virus first hypothesis which proposes viruses evolved independently from self-replicating RNA, 2) the reduction hypothesis which suggests viruses originated from reduced cellular organisms, and 3) the escape hypothesis where genetic material escaped cellular control and became parasitic. The document also discusses types of virus variation like mutation, hybridization, and pseudorecombination, as well as microevolution and macroevolution. It provides an example of how plant viruses can overcome Muller's Ratchet, which is the loss of critical functions in a population.
Serological detection techniques of plant viruses
This document discusses techniques for serologically detecting plant viruses. It begins by defining serology and its use in agriculture for detecting pathogens with variable or latent symptoms. It then describes the basics of antigen-antibody reactions and the types of antigens, antibodies, and reactions. The rest of the document focuses on specific serological tests used in plant virology, including liquid phase tests like precipitation, agglutination, and immunodiffusion assays as well as solid phase tests like ELISA, SDS-PAGE, ISEM, western blotting, and dot/tissue immunobinding assays. These tests allow detection of plant viruses through the reaction of viral coat proteins or antigens with specific antibodies.
Polyclonal and monoclonal antibody production
Monoclonal and polyclonal antibodies can be produced through different methods. Monoclonal antibodies are produced using hybridoma technology, which involves fusing myeloma cells with antibody-producing B cells to create immortal hybridoma cell lines. Kohler and Milstein developed this technique in 1975. Polyclonal antibodies involve immunizing an animal to produce a mixture of antibodies against various epitopes of an antigen. Monoclonal antibodies are highly specific to a single epitope, while polyclonal antibodies detect multiple epitopes but with less specificity. Monoclonal antibodies provide an unlimited supply of consistent, specific antibodies and are widely used in research and therapeutic applications.
Electron microscopy and production of antisera
Electron microscopy and production of antisera can be used to detect and identify plant viruses.
1) Electron microscopy can detect virus particles in infected plant tissue and identify unknown viruses. It is often combined with antisera in a technique called immuno electron microscopy.
2) Antisera are produced by injecting purified antigens into rabbits to stimulate an immune response and antibody production. Test bleedings are taken from the rabbits and the resulting antisera are evaluated for avidity, specificity, and titer against the target antigen.
Isolation and purification of plant viruses
The document summarizes the process of isolating and purifying plant viruses. It involves homogenizing infected plant leaves and extracting the sap containing viruses. The sap is then fractionated through low and high-speed centrifugation to separate out virus particles from other materials. The virus particles are further purified using density gradient centrifugation, which separates viruses based on their density through ultracentrifugation in layers of sucrose solutions with different densities. The purified virus band is collected and dialyzed to remove sucrose, yielding isolated and purified plant viruses. Key techniques used include density gradient centrifugation and ultracentrifugation.
Symptoms of plant viral diseases
This document summarizes common symptoms of plant viral diseases seen in leaves, including chlorosis, epinasty, enation, etching, leaf curling, leaf rolling, mosaic, mottle, necrosis, phyllody, proliferations, ringspot, stunting, stripe, stunting/dwarfing, tumours/galls, vein clearing, vein banding, yellowing, yellow mosaic. Examples are provided for each symptom along with a brief definition. A YouTube video with additional details is also referenced.
Methods of transmission of plant viruses
This document discusses various methods of plant virus transmission including mechanical, grafting, seed, insect, nematode, and fungal transmission. It provides details on each method such as the viruses transmitted, vectors involved, and procedures. Mechanical transmission involves sap inoculation using leaf rubbing or pinprick methods. Grafting and dodder transmission are also discussed. Seed and pollen transmission of certain viruses is possible. Insect vectors like aphids, whiteflies, and leafhoppers transmit many plant viruses in a circulative or non-persistent manner. Finally, nematodes and fungi can act as vectors for some viruses.
Virus vector relationship
This document discusses terminology related to virus transmission by vectors and different types of virus-vector relationships.
1. It defines terms like acquisition access period, acquisition feeding period, inoculation access period, inoculation feeding period, and transmission threshold that describe the process of a vector acquiring and transmitting a virus.
2. It describes three main types of virus-vector relationships: non-persistent, semi-persistent, and persistent. Non-persistent viruses are stylet-borne and lost quickly. Semi-persistent viruses persist for 10-100 hours in the foregut. Persistent viruses circulate and may multiply in the vector.
3. Within persistent viruses, it further distinguishes circulative non-propagative
Tobacco mosaic virus (tmv)
Tobacco mosaic virus (TMV) is a positive-sense single-stranded RNA virus that infects tobacco and other solanaceous plants. It has a genome of 6.4 kb made up of 5% RNA and 95% protein coat consisting of 2130 capsid subunits. TMV is a rigid helical rod-shaped virus particle measuring approximately 300 x 18 nm that can have its genome altered using adenosine diphosphate. Historic studies on TMV include the early discoveries by Mayer, Ivanovsky, and Beijerinck, as well as the work by Fraenkel-Conrat and Williams showing that purified TMV RNA and coat protein can self-assemble into functional virus
Chemical composition and physical properties of plant viruses
This document discusses the chemical composition and physical properties of plant viruses. It notes that plant viruses contain nucleic acids (RNA or DNA) and protein coats. The nucleic acid content ranges from 5-40% and determines infectivity, while the protein coat protects the nucleic acid and facilitates entry into host cells. It also discusses various physical properties of viruses like their thermal inactivation temperature, dilution endpoint, longevity in crude sap extractions, and use of local lesion assays to quantify infectivity.
SDSS1335+0728: The awakening of a ∼ 106M⊙ black hole⋆
Context. The early-type galaxy SDSS J133519.91+072807.4 (hereafter SDSS1335+0728), which had exhibited no prior optical variations during the preceding two decades, began showing significant nuclear variability in the Zwicky Transient Facility (ZTF) alert stream from December 2019 (as ZTF19acnskyy). This variability behaviour, coupled with the host-galaxy properties, suggests that SDSS1335+0728 hosts a ∼ 106M⊙ black hole (BH) that is currently in the process of ‘turning on’. Aims. We present a multi-wavelength photometric analysis and spectroscopic follow-up performed with the aim of better understanding the origin of the nuclear variations detected in SDSS1335+0728. Methods. We used archival photometry (from WISE, 2MASS, SDSS, GALEX, eROSITA) and spectroscopic data (from SDSS and LAMOST) to study the state of SDSS1335+0728 prior to December 2019, and new observations from Swift, SOAR/Goodman, VLT/X-shooter, and Keck/LRIS taken after its turn-on to characterise its current state. We analysed the variability of SDSS1335+0728 in the X-ray/UV/optical/mid-infrared range, modelled its spectral energy distribution prior to and after December 2019, and studied the evolution of its UV/optical spectra. Results. From our multi-wavelength photometric analysis, we find that: (a) since 2021, the UV flux (from Swift/UVOT observations) is four times brighter than the flux reported by GALEX in 2004; (b) since June 2022, the mid-infrared flux has risen more than two times, and the W1−W2 WISE colour has become redder; and (c) since February 2024, the source has begun showing X-ray emission. From our spectroscopic follow-up, we see that (i) the narrow emission line ratios are now consistent with a more energetic ionising continuum; (ii) broad emission lines are not detected; and (iii) the [OIII] line increased its flux ∼ 3.6 years after the first ZTF alert, which implies a relatively compact narrow-line-emitting region. Conclusions. We conclude that the variations observed in SDSS1335+0728 could be either explained by a ∼ 106M⊙ AGN that is just turning on or by an exotic tidal disruption event (TDE). If the former is true, SDSS1335+0728 is one of the strongest cases of an AGNobserved in the process of activating. If the latter were found to be the case, it would correspond to the longest and faintest TDE ever observed (or another class of still unknown nuclear transient). Future observations of SDSS1335+0728 are crucial to further understand its behaviour. Key words. galaxies: active– accretion, accretion discs– galaxies: individual: SDSS J133519.91+072807.4
More Related Content
More from N.H. Shankar Reddy
Phenomic approaches for plant disease detection
This document discusses various phenomic approaches for plant disease detection, including chlorophyll fluorescence imaging, hyperspectral imaging, thermal imaging, and image processing techniques. It provides details on how each approach works, such as using chlorophyll fluorescence to detect changes in photosynthesis before visual disease symptoms appear. The document also discusses the analysis of data collected from these approaches and how they can be used to rapidly screen large numbers of plant varieties for disease resistance and improve over traditional visual ratings.
Role of antimicrobial peptides in plant disease management
It is one of the advanced topics in plant disease management, detailed information about antimicrobial peptides and their role in plant disease management is furnished clearly.
Quarantine regulation and impact of modern detection methods
Detailed descriptions about quarantine and regulations, new laws, and new techniques are using in plant quarantine for the detection of plant pathogens are described
Bacteriophages and prions
This document discusses bacteriophages and prions. It defines bacteriophage as a virus that infects bacteria, and notes their discovery by Twort and d'Herelle. It describes the structure of bacteriophages like T4, including their DNA-containing heads and helical tails. The document outlines the lytic and lysogenic life cycles of bacteriophages and how they can be used to control plant diseases. Finally, it defines prions as infectious particles composed of misfolded protein that can induce normal proteins to take the same misfolded shape, and lists some animal diseases caused by prions.
Cross protection
Cross protection occurs when infection of a plant with a mild or attenuated virus strain protects the plant from later infection by a more severe strain of the same virus. This was first demonstrated in 1929 with tobacco mosaic virus. It has since been used successfully to control diseases caused by citrus tristeza virus and papaya ringspot virus. There are two main mechanisms of cross protection - coat protein-mediated resistance, which involves blocking virus uncoating or replication, and RNA-mediated resistance, where excess mild strain RNA hybridizes to block replication of the challenge virus. While cross protection has proven effective for some diseases, there are also limitations such as yield loss, incomplete protection, and genetic instability of the protector virus.
Production of disease free planting materials
Thermotherapy, tissue culture, chemotherapy, and electrotherapy are methods used to produce disease-free planting materials. Thermotherapy involves growing plants at high temperatures of 30-40°C for 2-3 months to eliminate viruses. Tissue culture techniques like callus culture, meristem tip culture, and protoplast culture can also produce virus-free plants. Chemotherapy uses antiviral chemicals or growth promoters during meristem tip culture. Electrotherapy applies electrical pulses to eliminate viruses. The document provides details on each method and examples of viruses eliminated from crops like banana, potato, and citrus using these approaches.
Anti viral principles
This document discusses antiviral principles (AVP) found in certain plant leaves and extracts. AVPs are compounds that have inhibitory effects against viruses. The document provides details on preparing an AVP extract from sorghum leaves and using it to manage pathogens. It explains that AVP extracts from various plants like sorghum, prosopis, and bougainvillea have been shown to effectively reduce different viruses in crops like groundnuts, tomatoes, and sunflowers. The mechanism of action of AVPs is that they contain proteins that interfere with viral replication and movement between host cells.
Principles of management of virus diseases
This document summarizes conventional and biotechnological approaches for managing viral plant diseases. Conventional approaches include using virus-free planting materials, cultural practices, vector management, heat therapy, meristem tip culture, and barrier crops. Biotechnological approaches involve pathogen-derived resistance through expression of viral coat proteins or RNA interference mechanisms to inhibit viral genes. The document provides examples and details of various conventional and biotechnological techniques for eliminating viruses from infected plants.
Movement of viruses, physiology of virus infected plants
This document summarizes the movement and physiology of virus-infected plants. It discusses three types of virus movement: intracellular, intercellular, and long-distance. Intracellular movement relies on the endoplasmic reticulum and cytoskeleton, while intercellular movement occurs through plasmodesmata connecting adjacent cells. Long-distance movement involves viruses entering the vascular system and moving systemically through the plant. It also examines effects on the infected plant's photosynthesis, respiration, membrane permeability, translocation, and transcription/translation, such as reduced chlorophyll and sucrose content as well as increased respiration and permeability.
Virus infection and replication
Virus infection and replication occurs in several steps:
1. The virus attaches to and enters the host plant cells, usually through wounds caused by vectors like insects or mechanical damage.
2. Once inside the cell, the viral genome is released from its protein coat through uncoating.
3. The viral genome then hijacks the host cell machinery to replicate, transcribe mRNA, and translate proteins.
New viral genomes and capsids are assembled and the mature virions are released to infect new cells.
Origin of viruses and virus strains
This document discusses the origin and evolution of viruses. It begins by defining key terms like isolate, variant, and strain. It then presents three main hypotheses for the origin of viruses: 1) the virus first hypothesis which proposes viruses evolved independently from self-replicating RNA, 2) the reduction hypothesis which suggests viruses originated from reduced cellular organisms, and 3) the escape hypothesis where genetic material escaped cellular control and became parasitic. The document also discusses types of virus variation like mutation, hybridization, and pseudorecombination, as well as microevolution and macroevolution. It provides an example of how plant viruses can overcome Muller's Ratchet, which is the loss of critical functions in a population.
Serological detection techniques of plant viruses
This document discusses techniques for serologically detecting plant viruses. It begins by defining serology and its use in agriculture for detecting pathogens with variable or latent symptoms. It then describes the basics of antigen-antibody reactions and the types of antigens, antibodies, and reactions. The rest of the document focuses on specific serological tests used in plant virology, including liquid phase tests like precipitation, agglutination, and immunodiffusion assays as well as solid phase tests like ELISA, SDS-PAGE, ISEM, western blotting, and dot/tissue immunobinding assays. These tests allow detection of plant viruses through the reaction of viral coat proteins or antigens with specific antibodies.
Polyclonal and monoclonal antibody production
Monoclonal and polyclonal antibodies can be produced through different methods. Monoclonal antibodies are produced using hybridoma technology, which involves fusing myeloma cells with antibody-producing B cells to create immortal hybridoma cell lines. Kohler and Milstein developed this technique in 1975. Polyclonal antibodies involve immunizing an animal to produce a mixture of antibodies against various epitopes of an antigen. Monoclonal antibodies are highly specific to a single epitope, while polyclonal antibodies detect multiple epitopes but with less specificity. Monoclonal antibodies provide an unlimited supply of consistent, specific antibodies and are widely used in research and therapeutic applications.
Electron microscopy and production of antisera
Electron microscopy and production of antisera can be used to detect and identify plant viruses.
1) Electron microscopy can detect virus particles in infected plant tissue and identify unknown viruses. It is often combined with antisera in a technique called immuno electron microscopy.
2) Antisera are produced by injecting purified antigens into rabbits to stimulate an immune response and antibody production. Test bleedings are taken from the rabbits and the resulting antisera are evaluated for avidity, specificity, and titer against the target antigen.
Isolation and purification of plant viruses
The document summarizes the process of isolating and purifying plant viruses. It involves homogenizing infected plant leaves and extracting the sap containing viruses. The sap is then fractionated through low and high-speed centrifugation to separate out virus particles from other materials. The virus particles are further purified using density gradient centrifugation, which separates viruses based on their density through ultracentrifugation in layers of sucrose solutions with different densities. The purified virus band is collected and dialyzed to remove sucrose, yielding isolated and purified plant viruses. Key techniques used include density gradient centrifugation and ultracentrifugation.
Symptoms of plant viral diseases
This document summarizes common symptoms of plant viral diseases seen in leaves, including chlorosis, epinasty, enation, etching, leaf curling, leaf rolling, mosaic, mottle, necrosis, phyllody, proliferations, ringspot, stunting, stripe, stunting/dwarfing, tumours/galls, vein clearing, vein banding, yellowing, yellow mosaic. Examples are provided for each symptom along with a brief definition. A YouTube video with additional details is also referenced.
Methods of transmission of plant viruses
This document discusses various methods of plant virus transmission including mechanical, grafting, seed, insect, nematode, and fungal transmission. It provides details on each method such as the viruses transmitted, vectors involved, and procedures. Mechanical transmission involves sap inoculation using leaf rubbing or pinprick methods. Grafting and dodder transmission are also discussed. Seed and pollen transmission of certain viruses is possible. Insect vectors like aphids, whiteflies, and leafhoppers transmit many plant viruses in a circulative or non-persistent manner. Finally, nematodes and fungi can act as vectors for some viruses.
Virus vector relationship
This document discusses terminology related to virus transmission by vectors and different types of virus-vector relationships.
1. It defines terms like acquisition access period, acquisition feeding period, inoculation access period, inoculation feeding period, and transmission threshold that describe the process of a vector acquiring and transmitting a virus.
2. It describes three main types of virus-vector relationships: non-persistent, semi-persistent, and persistent. Non-persistent viruses are stylet-borne and lost quickly. Semi-persistent viruses persist for 10-100 hours in the foregut. Persistent viruses circulate and may multiply in the vector.
3. Within persistent viruses, it further distinguishes circulative non-propagative
Tobacco mosaic virus (tmv)
Tobacco mosaic virus (TMV) is a positive-sense single-stranded RNA virus that infects tobacco and other solanaceous plants. It has a genome of 6.4 kb made up of 5% RNA and 95% protein coat consisting of 2130 capsid subunits. TMV is a rigid helical rod-shaped virus particle measuring approximately 300 x 18 nm that can have its genome altered using adenosine diphosphate. Historic studies on TMV include the early discoveries by Mayer, Ivanovsky, and Beijerinck, as well as the work by Fraenkel-Conrat and Williams showing that purified TMV RNA and coat protein can self-assemble into functional virus
Chemical composition and physical properties of plant viruses
This document discusses the chemical composition and physical properties of plant viruses. It notes that plant viruses contain nucleic acids (RNA or DNA) and protein coats. The nucleic acid content ranges from 5-40% and determines infectivity, while the protein coat protects the nucleic acid and facilitates entry into host cells. It also discusses various physical properties of viruses like their thermal inactivation temperature, dilution endpoint, longevity in crude sap extractions, and use of local lesion assays to quantify infectivity.
More from N.H. Shankar Reddy (20)
Role of antimicrobial peptides in plant disease management
Role of antimicrobial peptides in plant disease management
Quarantine regulation and impact of modern detection methods
Quarantine regulation and impact of modern detection methods
Movement of viruses, physiology of virus infected plants
Movement of viruses, physiology of virus infected plants
Chemical composition and physical properties of plant viruses
Chemical composition and physical properties of plant viruses
Recently uploaded
SDSS1335+0728: The awakening of a ∼ 106M⊙ black hole⋆
Context. The early-type galaxy SDSS J133519.91+072807.4 (hereafter SDSS1335+0728), which had exhibited no prior optical variations during the preceding two decades, began showing significant nuclear variability in the Zwicky Transient Facility (ZTF) alert stream from December 2019 (as ZTF19acnskyy). This variability behaviour, coupled with the host-galaxy properties, suggests that SDSS1335+0728 hosts a ∼ 106M⊙ black hole (BH) that is currently in the process of ‘turning on’. Aims. We present a multi-wavelength photometric analysis and spectroscopic follow-up performed with the aim of better understanding the origin of the nuclear variations detected in SDSS1335+0728. Methods. We used archival photometry (from WISE, 2MASS, SDSS, GALEX, eROSITA) and spectroscopic data (from SDSS and LAMOST) to study the state of SDSS1335+0728 prior to December 2019, and new observations from Swift, SOAR/Goodman, VLT/X-shooter, and Keck/LRIS taken after its turn-on to characterise its current state. We analysed the variability of SDSS1335+0728 in the X-ray/UV/optical/mid-infrared range, modelled its spectral energy distribution prior to and after December 2019, and studied the evolution of its UV/optical spectra. Results. From our multi-wavelength photometric analysis, we find that: (a) since 2021, the UV flux (from Swift/UVOT observations) is four times brighter than the flux reported by GALEX in 2004; (b) since June 2022, the mid-infrared flux has risen more than two times, and the W1−W2 WISE colour has become redder; and (c) since February 2024, the source has begun showing X-ray emission. From our spectroscopic follow-up, we see that (i) the narrow emission line ratios are now consistent with a more energetic ionising continuum; (ii) broad emission lines are not detected; and (iii) the [OIII] line increased its flux ∼ 3.6 years after the first ZTF alert, which implies a relatively compact narrow-line-emitting region. Conclusions. We conclude that the variations observed in SDSS1335+0728 could be either explained by a ∼ 106M⊙ AGN that is just turning on or by an exotic tidal disruption event (TDE). If the former is true, SDSS1335+0728 is one of the strongest cases of an AGNobserved in the process of activating. If the latter were found to be the case, it would correspond to the longest and faintest TDE ever observed (or another class of still unknown nuclear transient). Future observations of SDSS1335+0728 are crucial to further understand its behaviour. Key words. galaxies: active– accretion, accretion discs– galaxies: individual: SDSS J133519.91+072807.4
Explainable Deepfake Image/Video Detection
Presentation of our paper, "Towards Quantitative Evaluation of Explainable AI Methods for Deepfake Detection", by K. Tsigos, E. Apostolidis, S. Baxevanakis, S. Papadopoulos, V. Mezaris. Presented at the ACM Int. Workshop on Multimedia AI against Disinformation (MAD’24) of the ACM Int. Conf. on Multimedia Retrieval (ICMR’24), Thailand, June 2024. https://doi.org/10.1145/3643491.3660292 https://arxiv.org/abs/2404.18649
Software available at https://github.com/IDT-ITI/XAI-Deepfakes
Discovery of An Apparent Red, High-Velocity Type Ia Supernova at 𝐳 = 2.9 wi...
We present the JWST discovery of SN 2023adsy, a transient object located in a host galaxy JADES-GS
+
53.13485
−
27.82088
with a host spectroscopic redshift of
2.903
±
0.007
. The transient was identified in deep James Webb Space Telescope (JWST)/NIRCam imaging from the JWST Advanced Deep Extragalactic Survey (JADES) program. Photometric and spectroscopic followup with NIRCam and NIRSpec, respectively, confirm the redshift and yield UV-NIR light-curve, NIR color, and spectroscopic information all consistent with a Type Ia classification. Despite its classification as a likely SN Ia, SN 2023adsy is both fairly red (
�
(
�
−
�
)
∼
0.9
) despite a host galaxy with low-extinction and has a high Ca II velocity (
19
,
000
±
2
,
000
km/s) compared to the general population of SNe Ia. While these characteristics are consistent with some Ca-rich SNe Ia, particularly SN 2016hnk, SN 2023adsy is intrinsically brighter than the low-
�
Ca-rich population. Although such an object is too red for any low-
�
cosmological sample, we apply a fiducial standardization approach to SN 2023adsy and find that the SN 2023adsy luminosity distance measurement is in excellent agreement (
≲
1
�
) with
Λ
CDM. Therefore unlike low-
�
Ca-rich SNe Ia, SN 2023adsy is standardizable and gives no indication that SN Ia standardized luminosities change significantly with redshift. A larger sample of distant SNe Ia is required to determine if SN Ia population characteristics at high-
�
truly diverge from their low-
�
counterparts, and to confirm that standardized luminosities nevertheless remain constant with redshift.
Compositions of iron-meteorite parent bodies constrainthe structure of the pr...
Magmatic iron-meteorite parent bodies are the earliest planetesimals in the Solar System,and they preserve information about conditions and planet-forming processes in thesolar nebula. In this study, we include comprehensive elemental compositions andfractional-crystallization modeling for iron meteorites from the cores of five differenti-ated asteroids from the inner Solar System. Together with previous results of metalliccores from the outer Solar System, we conclude that asteroidal cores from the outerSolar System have smaller sizes, elevated siderophile-element abundances, and simplercrystallization processes than those from the inner Solar System. These differences arerelated to the formation locations of the parent asteroids because the solar protoplane-tary disk varied in redox conditions, elemental distributions, and dynamics at differentheliocentric distances. Using highly siderophile-element data from iron meteorites, wereconstruct the distribution of calcium-aluminum-rich inclusions (CAIs) across theprotoplanetary disk within the first million years of Solar-System history. CAIs, the firstsolids to condense in the Solar System, formed close to the Sun. They were, however,concentrated within the outer disk and depleted within the inner disk. Future modelsof the structure and evolution of the protoplanetary disk should account for this dis-tribution pattern of CAIs.
Mechanisms and Applications of Antiviral Neutralizing Antibodies - Creative B...
Neutralizing antibodies, pivotal in immune defense, specifically bind and inhibit viral pathogens, thereby playing a crucial role in protecting against and mitigating infectious diseases. In this slide, we will introduce what antibodies and neutralizing antibodies are, the production and regulation of neutralizing antibodies, their mechanisms of action, classification and applications, as well as the challenges they face.
Analysis of Polygenic Traits (GPB-602)
Quantitative genetics – study of inheritance of quantitative characters or polygenic characters in experimental populations.
Sexuality - Issues, Attitude and Behaviour - Applied Social Psychology - Psyc...
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
Holsinger, Bruce W. - Music, body and desire in medieval culture [2001].pdf
Music and Medieval History
Evidence of Jet Activity from the Secondary Black Hole in the OJ 287 Binary S...
Wereport the study of a huge optical intraday flare on 2021 November 12 at 2 a.m. UT in the blazar OJ287. In the binary black hole model, it is associated with an impact of the secondary black hole on the accretion disk of the primary. Our multifrequency observing campaign was set up to search for such a signature of the impact based on a prediction made 8 yr earlier. The first I-band results of the flare have already been reported by Kishore et al. (2024). Here we combine these data with our monitoring in the R-band. There is a big change in the R–I spectral index by 1.0 ±0.1 between the normal background and the flare, suggesting a new component of radiation. The polarization variation during the rise of the flare suggests the same. The limits on the source size place it most reasonably in the jet of the secondary BH. We then ask why we have not seen this phenomenon before. We show that OJ287 was never before observed with sufficient sensitivity on the night when the flare should have happened according to the binary model. We also study the probability that this flare is just an oversized example of intraday variability using the Krakow data set of intense monitoring between 2015 and 2023. We find that the occurrence of a flare of this size and rapidity is unlikely. In machine-readable Tables 1 and 2, we give the full orbit-linked historical light curve of OJ287 as well as the dense monitoring sample of Krakow.
Evaluation and Identification of J'BaFofi the Giant Spider of Congo and Moke...
ABSTRACT
The J'BaFofi, or "Giant Spider," is a mainly legendary arachnid by reportedly inhabiting the dense rain forests of
the Congo. As despite numerous anecdotal accounts and cultural references, the scientific validation remains more elusive.
My study aims to proper evaluate the existence of the J'BaFofi through the analysis of historical reports,indigenous
testimonies and modern exploration efforts.
Mechanics:- Simple and Compound Pendulum
a compound pendulum is a physical system with a more complex structure than a simple pendulum, incorporating its mass distribution and dimensions into its oscillatory motion around a fixed axis. Understanding its dynamics involves principles of rotational mechanics and the interplay between gravitational potential energy and kinetic energy. Compound pendulums are used in various scientific and engineering applications, such as seismology for measuring earthquakes, in clocks to maintain accurate timekeeping, and in mechanical systems to study oscillatory motion dynamics.
seed production, Nursery & Gardening.pdf
This presentation offers a general idea of the structure of seed, seed production, management of seeds and its allied technologies. It also offers the concept of gene erosion and the practices used to control it. Nursery and gardening have been widely explored along with their importance in the related domain.
TOPIC OF DISCUSSION: CENTRIFUGATION SLIDESHARE.pptx
Centrifugation is a powerful technique used in laboratories to separate components of a heterogeneous mixture based on their density. This process utilizes centrifugal force to rapidly spin samples, causing denser particles to migrate outward more quickly than lighter ones. As a result, distinct layers form within the sample tube, allowing for easy isolation and purification of target substances.
Signatures of wave erosion in Titan’s coasts
The shorelines of Titan’s hydrocarbon seas trace flooded erosional landforms such as river valleys; however, it isunclear whether coastal erosion has subsequently altered these shorelines. Spacecraft observations and theo-retical models suggest that wind may cause waves to form on Titan’s seas, potentially driving coastal erosion,but the observational evidence of waves is indirect, and the processes affecting shoreline evolution on Titanremain unknown. No widely accepted framework exists for using shoreline morphology to quantitatively dis-cern coastal erosion mechanisms, even on Earth, where the dominant mechanisms are known. We combinelandscape evolution models with measurements of shoreline shape on Earth to characterize how differentcoastal erosion mechanisms affect shoreline morphology. Applying this framework to Titan, we find that theshorelines of Titan’s seas are most consistent with flooded landscapes that subsequently have been eroded bywaves, rather than a uniform erosional process or no coastal erosion, particularly if wave growth saturates atfetch lengths of tens of kilometers.
Recently uploaded (20)
SDSS1335+0728: The awakening of a ∼ 106M⊙ black hole⋆
SDSS1335+0728: The awakening of a ∼ 106M⊙ black hole⋆
Discovery of An Apparent Red, High-Velocity Type Ia Supernova at 𝐳 = 2.9 wi...
Discovery of An Apparent Red, High-Velocity Type Ia Supernova at 𝐳 = 2.9 wi...
Compositions of iron-meteorite parent bodies constrainthe structure of the pr...
Compositions of iron-meteorite parent bodies constrainthe structure of the pr...
Mechanisms and Applications of Antiviral Neutralizing Antibodies - Creative B...
Mechanisms and Applications of Antiviral Neutralizing Antibodies - Creative B...
Sexuality - Issues, Attitude and Behaviour - Applied Social Psychology - Psyc...
Sexuality - Issues, Attitude and Behaviour - Applied Social Psychology - Psyc...
Juaristi, Jon. - El canon espanol. El legado de la cultura española a la civi...
Juaristi, Jon. - El canon espanol. El legado de la cultura española a la civi...
Holsinger, Bruce W. - Music, body and desire in medieval culture [2001].pdf
Holsinger, Bruce W. - Music, body and desire in medieval culture [2001].pdf
Evidence of Jet Activity from the Secondary Black Hole in the OJ 287 Binary S...
Evidence of Jet Activity from the Secondary Black Hole in the OJ 287 Binary S...
Evaluation and Identification of J'BaFofi the Giant Spider of Congo and Moke...
Evaluation and Identification of J'BaFofi the Giant Spider of Congo and Moke...
TOPIC OF DISCUSSION: CENTRIFUGATION SLIDESHARE.pptx
TOPIC OF DISCUSSION: CENTRIFUGATION SLIDESHARE.pptx
Saccharomycotina
- 1. SACCHAROMYCOTINA N.H. SHANKAR REDDY 2nd Ph.D. Plant Pathology Annamalai University
- 3. • Yeasts are comes under this group Budding yeast – Saccharomyces fission yeast – Schizosaccharomyces • Ascomata totally absent, the asci are not borne on the ascogenous hyphae • Asexual reproduction through budding, conidia, fission (arthrospores)