bacteria can enters into plants by different mechanisms and the slides which includes different mode of entries into plants, and this information is also important for students who are preparing for NET exams.
This document discusses various methods for controlling plant diseases. The major methods discussed are cultural control methods, biological control methods, and chemical control methods. Cultural control methods include avoiding contact between the pathogen and host plant through proper field selection, resistant varieties, and modifying cultural practices. Biological control uses other organisms like fungi, bacteria, and mycorrhizal fungi to control pathogens. Chemical control involves the use of fungicides, bactericides, and other chemical treatments to directly kill or inhibit pathogens.
This presentation discusses powdery mildew, a fungal disease that affects many plants. It takes nutrients from plants, weakening them and reducing blooms and fruit production if left untreated. Powdery mildew spores spread via wind or insects and thrive in humid conditions with moderate temperatures. It appears as a powdery white growth on leaves and stems. While not always fatal, it can stress plants. Susceptible plants include grapes, squash and roses. Prevention focuses on resistant varieties, air flow, proper care and fungicide application if needed.
Hypersensitivity and its Mechanism summarizes the hypersensitive response (HR) in plants. The HR is a localized cell death response at the site of infection that limits pathogen growth and provides resistance. It involves the recognition of pathogen elicitors by plant receptors, which activates a biochemical reaction cascade and the production of reactive oxygen species and defense compounds. This leads to cell death in infected areas and the acquisition of systemic resistance in other plant tissues through signaling molecules like salicylic acid, jasmonic acid, and ethylene. The HR occurs through specific host-pathogen combinations and results in the depolarization of membranes and disintegration of cellular components at the infection site.
Role of microbial toxins in plant pathogenesisansarishahid786
This document discusses the role of microbial toxins in plant pathogenesis. It defines toxins as metabolites excreted or released by pathogens that damage host cells. Toxins are classified based on their source and specificity. Host-specific toxins only affect a pathogen's host, while non-host specific toxins can damage unrelated plants. Toxins disrupt cell permeability, metabolic processes, and growth regulation, injuring and killing host cells. They play an important role in disease development and symptom expression.
This document discusses toxins produced by plant pathogens. It begins by classifying toxins into three categories: pathotoxins, phytotoxins, and vivotoxins. It then discusses specific toxins in more detail, distinguishing between host-specific toxins and non-host specific toxins. Examples of both types of toxins are provided, along with descriptions of their modes of action and effects on host tissues. Overall, the document reviews the role of toxins in plant disease development and pathogenesis.
Red rot of sugarcane is caused by the fungus Colletotrichum falcatum. It was first reported in 1893 in Java and causes significant losses in sugarcane crops. Symptoms include yellowing of leaves, shriveled canes that are light in weight and easily broken with reddening of the pith. The pathogen survives in plant setts, infected plant debris, and soil. Management strategies include using disease-free setts, hot water or hot air treatment of setts, removing infected plant material, crop rotation, and growing resistant varieties.
Chemical control of plant diseases involves using chemicals like bactericides, fungicides, and nematicides to inhibit or kill pathogens. Bactericides rely on copper and treat bacterial diseases. Fungicides disrupt fungal cellular processes and are applied as sprays, dusts, or to seeds. Nematicides like aldicarb kill nematodes. Chemicals are applied through soil treatments, seed treatments, or foliar sprays. While effective, chemicals can harm non-target organisms and accumulate up the food chain.
bacteria can enters into plants by different mechanisms and the slides which includes different mode of entries into plants, and this information is also important for students who are preparing for NET exams.
This document discusses various methods for controlling plant diseases. The major methods discussed are cultural control methods, biological control methods, and chemical control methods. Cultural control methods include avoiding contact between the pathogen and host plant through proper field selection, resistant varieties, and modifying cultural practices. Biological control uses other organisms like fungi, bacteria, and mycorrhizal fungi to control pathogens. Chemical control involves the use of fungicides, bactericides, and other chemical treatments to directly kill or inhibit pathogens.
This presentation discusses powdery mildew, a fungal disease that affects many plants. It takes nutrients from plants, weakening them and reducing blooms and fruit production if left untreated. Powdery mildew spores spread via wind or insects and thrive in humid conditions with moderate temperatures. It appears as a powdery white growth on leaves and stems. While not always fatal, it can stress plants. Susceptible plants include grapes, squash and roses. Prevention focuses on resistant varieties, air flow, proper care and fungicide application if needed.
Hypersensitivity and its Mechanism summarizes the hypersensitive response (HR) in plants. The HR is a localized cell death response at the site of infection that limits pathogen growth and provides resistance. It involves the recognition of pathogen elicitors by plant receptors, which activates a biochemical reaction cascade and the production of reactive oxygen species and defense compounds. This leads to cell death in infected areas and the acquisition of systemic resistance in other plant tissues through signaling molecules like salicylic acid, jasmonic acid, and ethylene. The HR occurs through specific host-pathogen combinations and results in the depolarization of membranes and disintegration of cellular components at the infection site.
Role of microbial toxins in plant pathogenesisansarishahid786
This document discusses the role of microbial toxins in plant pathogenesis. It defines toxins as metabolites excreted or released by pathogens that damage host cells. Toxins are classified based on their source and specificity. Host-specific toxins only affect a pathogen's host, while non-host specific toxins can damage unrelated plants. Toxins disrupt cell permeability, metabolic processes, and growth regulation, injuring and killing host cells. They play an important role in disease development and symptom expression.
This document discusses toxins produced by plant pathogens. It begins by classifying toxins into three categories: pathotoxins, phytotoxins, and vivotoxins. It then discusses specific toxins in more detail, distinguishing between host-specific toxins and non-host specific toxins. Examples of both types of toxins are provided, along with descriptions of their modes of action and effects on host tissues. Overall, the document reviews the role of toxins in plant disease development and pathogenesis.
Red rot of sugarcane is caused by the fungus Colletotrichum falcatum. It was first reported in 1893 in Java and causes significant losses in sugarcane crops. Symptoms include yellowing of leaves, shriveled canes that are light in weight and easily broken with reddening of the pith. The pathogen survives in plant setts, infected plant debris, and soil. Management strategies include using disease-free setts, hot water or hot air treatment of setts, removing infected plant material, crop rotation, and growing resistant varieties.
Chemical control of plant diseases involves using chemicals like bactericides, fungicides, and nematicides to inhibit or kill pathogens. Bactericides rely on copper and treat bacterial diseases. Fungicides disrupt fungal cellular processes and are applied as sprays, dusts, or to seeds. Nematicides like aldicarb kill nematodes. Chemicals are applied through soil treatments, seed treatments, or foliar sprays. While effective, chemicals can harm non-target organisms and accumulate up the food chain.
Principles of plant disease managementRanjan Kumar
This document discusses principles of plant disease management. It explains that a plant disease is caused by the impairment of a plant's normal physiological functioning due to irritation from pathogens. Disease management aims to prevent disease incidence, reduce pathogen inoculum, and minimize crop losses. It does this by eliminating interactions between susceptible hosts, virulent pathogens, and suitable environments. The key principles of disease management are avoidance, exclusion, eradication, protection, use of resistant varieties, and therapy. Each principle is described in detail with examples.
1. The document discusses the defense mechanisms of plants against plant pathogens, including structural and biochemical defenses.
2. Structural defenses include pre-existing structures like wax, thick cuticles, and thick-walled cells, as well as induced structures like cork layers and tyloses formation in response to infection.
3. Biochemical defenses include pre-existing inhibitors and phenolic compounds, as well as induced responses like phytoalexin production, hypersensitive response, and pathogenesis-related protein synthesis post-infection.
4. Both structural and biochemical defenses work together and are influenced by factors like the plant's age, organ infected, and environmental conditions.
Variability arises in plant pathogens through various genetic mechanisms such as mutation, hybridization, and recombination. This variability allows pathogens to evolve new races or strains that can infect resistant host varieties and overcome plant resistance. The document discusses several mechanisms that generate variability in fungi, bacteria, and viruses, including mutation, transformation, transduction, conjugation, heterokaryosis, parasexualism, and recombination, which allow pathogens to adapt to new environments and hosts. Understanding pathogen variability is important for breeding disease-resistant crop varieties.
Sugarcane Grassy shoot and Ratoon stunting diseasesvasanthkumar650
This document provides information on two diseases that affect sugarcane: grassy shoot disease and ratoon stunting disease. Grassy shoot disease causes stunted growth, narrow leaves, and a bunchy appearance. It is caused by phytoplasma and spread by leafhoppers and aphids. Ratoon stunting disease causes stunting and reduced yields. Its symptoms are subtle. It is caused by the bacterium Leifsonia xyli and spread through infected cuttings and contaminated equipment. Management of both diseases involves use of healthy planting material, crop rotation, rogueing of infected plants, and disinfection of equipment.
The document discusses various methods for controlling plant diseases, including regulatory, cultural, biological, physical, and chemical methods. Regulatory methods aim to prevent the spread of pathogens through quarantines and inspections. Cultural methods manipulate the environment and genetics of plants, such as host eradication, crop rotation, and improving growing conditions. Biological methods use other organisms like resistant plant varieties and hyperparasites. Physical methods employ heat, refrigeration, and radiation. Chemical methods apply fungicides, bactericides, and insecticides through foliage sprays and dusts.
1. The document discusses plant pathogens and the enzymes they secrete to degrade plant cell walls and tissues. It describes the primary components of cuticles, cell walls, and middle lamella that pathogens target, including cutin, cellulose, pectin, hemicellulose, and lignin.
2. The key cell wall-degrading enzymes produced by pathogens are discussed, such as cutinases, pectinases, cellulases, hemicellulases, lignin-degrading enzymes, and proteases. Examples are given of pathogens and the roles of specific enzymes in disease development.
3. Effects of pathogens on physiological processes like photosynthesis, translocation of water and nutrients, respiration,
Banana bunchy top is a serious viral disease of bananas caused by the Banana bunchy top virus (BBTV). It is transmitted by the banana aphid (Pentalonia nigronervosa). Symptoms include dark green streaks on leaves and petioles, chlorotic and upright leaves clustered at the top forming a "bunchy top". The disease reduces fruit production and quality. Management involves using virus-free planting materials, rogueing infected plants, controlling the vector with insecticides, and maintaining weed-free fields. BBTV has had major economic impacts on banana industries worldwide.
- Hypersensitivity is a plant defense mechanism characterized by rapid programmed cell death at the site of infection to prevent pathogen spread. It is initiated by the recognition of pathogen elicitors by plant resistance proteins.
- This triggers biochemical responses like reactive oxygen species production and phytoalexin accumulation that cause cell death around the infection site. This localized cell death limits the pathogen to a small area and prevents disease development.
- The hypersensitive response is an example of incompatible interactions between plants with specific resistance genes and pathogens with corresponding avirulence genes. It represents a successful defense strategy employed by plants.
EFFECT OF PATHOGEN ON HOST PLANT PHYSIOLOGYfarheen khan
Plant pathogens can interfere with key plant physiological functions such as photosynthesis, respiration, transpiration, nutrient transport, and cellular processes. This document discusses how pathogens disrupt these functions through tissue damage, toxin production, and cellular changes. Specifically, it notes that pathogens reduce photosynthesis by destroying chlorophyll or inhibiting related enzymes. They also increase plant respiration and interfere with nutrient transport through the xylem and phloem.
In this PPT you will come to know about the different types of mosaic virus which is caused in BHENDU crop, its life cycle, epidemiology, and its management.
The document discusses systemic acquired resistance (SAR), which confers long-lasting protection against a broad spectrum of pathogens. SAR is induced by initial infection and involves the signaling molecule salicylic acid, leading to accumulation of pathogenesis-related proteins throughout the plant. Key regulators of SAR include NPR1, which is required for SAR, and salicylic acid, which is involved in transmitting the defense signal systemically.
Red rot of sugarcane is caused by the fungus Colletotrichum falcatum. It was first identified in Java in 1893 and causes significant economic losses by reducing cane weight and sugar recovery. Symptoms include reddening of the stalk pith and small red spots on leaves. The disease spreads through infected soil and planting material. Management strategies include crop rotation, sanitation, resistant varieties, and hot water treatment of setts.
This document summarizes information about the stem rust of wheat caused by the fungus Puccinia graminis. It discusses the significance of wheat as a crop and losses caused by stem rust. It describes the disease symptoms, life cycle involving both wheat and barberry hosts, epidemiology and factors influencing disease spread. It also outlines management strategies for stem rust including growing resistant varieties and chemical control methods.
Systemic acquired resistance (SAR) is a whole-plant immune response that is activated upon localized infection by a pathogen. It provides long-lasting, broad-spectrum resistance against secondary infections. SAR involves the production of mobile signaling molecules like methyl salicylate, azelaic acid, and glycerol-3-phosphate in infected tissues that activate defenses in distant, uninfected tissues. This results in increased expression of pathogenesis-related proteins and other defenses. The NPR1 protein is a master regulator of the SAR response.
The document discusses the role of enzymes, toxins, and growth regulators in plant pathology and disease development. It defines plant pathology and describes how diseases develop through a complex process influenced by environmental factors and stress. The summary is:
1) Plant pathology studies plant diseases and their causes and controls. Disease develops through interactions between pathogens, hosts, and the environment.
2) Key stages of disease development include inoculation, penetration, infection, pathogen growth and reproduction, and dissemination. Disease occurs when conditions are suitable for the pathogen but not the host.
3) Factors like temperature, moisture, light, soil properties, and wind influence disease development by affecting the pathogen, host, or their interaction. Understanding
This document discusses how plant pathogens cause disease in plants. It explains that pathogens produce enzymes and other substances that allow them to degrade the structural barriers in plant cell walls like cutin, cellulose, pectin, and lignin. This allows the pathogens to enter plant tissues and obtain nutrients. It provides examples of specific enzymes produced by different pathogenic fungi, bacteria, and nematodes to degrade wax, cutin, cellulose, hemicellulose, pectin, protein, starch, and lipids. Degrading these plant cell wall components weakens plant tissues and interferes with their metabolic processes.
This document discusses principles of disease control in agricultural microbiology. It outlines four main principles: 1) Avoidance/Exclusion to prevent import and spread of pathogens, 2) Eradiation to reduce pathogen amounts, 3) Protection to directly protect plants from infection, and 4) Resistant varieties that hinder pathogen development. Specific control methods are described under each principle, including quarantine, sanitation, crop rotation, biological and chemical controls, and genetic engineering to develop resistant varieties.
The document discusses host-parasite relationships and the mechanisms of plant infection. It covers:
1. How fungi obtain food from host plants through haustoria and establish close connections.
2. The definition of host and parasite. Host-parasite relationships affect each other's growth and metabolism.
3. The mechanisms of infection include spores contacting hosts, germ tubes attaching and penetrating tissues using enzymes, and hyphae entering and spreading within host tissues. Pathogens can enter through natural openings or wounds.
Principles of plant disease managementRanjan Kumar
This document discusses principles of plant disease management. It explains that a plant disease is caused by the impairment of a plant's normal physiological functioning due to irritation from pathogens. Disease management aims to prevent disease incidence, reduce pathogen inoculum, and minimize crop losses. It does this by eliminating interactions between susceptible hosts, virulent pathogens, and suitable environments. The key principles of disease management are avoidance, exclusion, eradication, protection, use of resistant varieties, and therapy. Each principle is described in detail with examples.
1. The document discusses the defense mechanisms of plants against plant pathogens, including structural and biochemical defenses.
2. Structural defenses include pre-existing structures like wax, thick cuticles, and thick-walled cells, as well as induced structures like cork layers and tyloses formation in response to infection.
3. Biochemical defenses include pre-existing inhibitors and phenolic compounds, as well as induced responses like phytoalexin production, hypersensitive response, and pathogenesis-related protein synthesis post-infection.
4. Both structural and biochemical defenses work together and are influenced by factors like the plant's age, organ infected, and environmental conditions.
Variability arises in plant pathogens through various genetic mechanisms such as mutation, hybridization, and recombination. This variability allows pathogens to evolve new races or strains that can infect resistant host varieties and overcome plant resistance. The document discusses several mechanisms that generate variability in fungi, bacteria, and viruses, including mutation, transformation, transduction, conjugation, heterokaryosis, parasexualism, and recombination, which allow pathogens to adapt to new environments and hosts. Understanding pathogen variability is important for breeding disease-resistant crop varieties.
Sugarcane Grassy shoot and Ratoon stunting diseasesvasanthkumar650
This document provides information on two diseases that affect sugarcane: grassy shoot disease and ratoon stunting disease. Grassy shoot disease causes stunted growth, narrow leaves, and a bunchy appearance. It is caused by phytoplasma and spread by leafhoppers and aphids. Ratoon stunting disease causes stunting and reduced yields. Its symptoms are subtle. It is caused by the bacterium Leifsonia xyli and spread through infected cuttings and contaminated equipment. Management of both diseases involves use of healthy planting material, crop rotation, rogueing of infected plants, and disinfection of equipment.
The document discusses various methods for controlling plant diseases, including regulatory, cultural, biological, physical, and chemical methods. Regulatory methods aim to prevent the spread of pathogens through quarantines and inspections. Cultural methods manipulate the environment and genetics of plants, such as host eradication, crop rotation, and improving growing conditions. Biological methods use other organisms like resistant plant varieties and hyperparasites. Physical methods employ heat, refrigeration, and radiation. Chemical methods apply fungicides, bactericides, and insecticides through foliage sprays and dusts.
1. The document discusses plant pathogens and the enzymes they secrete to degrade plant cell walls and tissues. It describes the primary components of cuticles, cell walls, and middle lamella that pathogens target, including cutin, cellulose, pectin, hemicellulose, and lignin.
2. The key cell wall-degrading enzymes produced by pathogens are discussed, such as cutinases, pectinases, cellulases, hemicellulases, lignin-degrading enzymes, and proteases. Examples are given of pathogens and the roles of specific enzymes in disease development.
3. Effects of pathogens on physiological processes like photosynthesis, translocation of water and nutrients, respiration,
Banana bunchy top is a serious viral disease of bananas caused by the Banana bunchy top virus (BBTV). It is transmitted by the banana aphid (Pentalonia nigronervosa). Symptoms include dark green streaks on leaves and petioles, chlorotic and upright leaves clustered at the top forming a "bunchy top". The disease reduces fruit production and quality. Management involves using virus-free planting materials, rogueing infected plants, controlling the vector with insecticides, and maintaining weed-free fields. BBTV has had major economic impacts on banana industries worldwide.
- Hypersensitivity is a plant defense mechanism characterized by rapid programmed cell death at the site of infection to prevent pathogen spread. It is initiated by the recognition of pathogen elicitors by plant resistance proteins.
- This triggers biochemical responses like reactive oxygen species production and phytoalexin accumulation that cause cell death around the infection site. This localized cell death limits the pathogen to a small area and prevents disease development.
- The hypersensitive response is an example of incompatible interactions between plants with specific resistance genes and pathogens with corresponding avirulence genes. It represents a successful defense strategy employed by plants.
EFFECT OF PATHOGEN ON HOST PLANT PHYSIOLOGYfarheen khan
Plant pathogens can interfere with key plant physiological functions such as photosynthesis, respiration, transpiration, nutrient transport, and cellular processes. This document discusses how pathogens disrupt these functions through tissue damage, toxin production, and cellular changes. Specifically, it notes that pathogens reduce photosynthesis by destroying chlorophyll or inhibiting related enzymes. They also increase plant respiration and interfere with nutrient transport through the xylem and phloem.
In this PPT you will come to know about the different types of mosaic virus which is caused in BHENDU crop, its life cycle, epidemiology, and its management.
The document discusses systemic acquired resistance (SAR), which confers long-lasting protection against a broad spectrum of pathogens. SAR is induced by initial infection and involves the signaling molecule salicylic acid, leading to accumulation of pathogenesis-related proteins throughout the plant. Key regulators of SAR include NPR1, which is required for SAR, and salicylic acid, which is involved in transmitting the defense signal systemically.
Red rot of sugarcane is caused by the fungus Colletotrichum falcatum. It was first identified in Java in 1893 and causes significant economic losses by reducing cane weight and sugar recovery. Symptoms include reddening of the stalk pith and small red spots on leaves. The disease spreads through infected soil and planting material. Management strategies include crop rotation, sanitation, resistant varieties, and hot water treatment of setts.
This document summarizes information about the stem rust of wheat caused by the fungus Puccinia graminis. It discusses the significance of wheat as a crop and losses caused by stem rust. It describes the disease symptoms, life cycle involving both wheat and barberry hosts, epidemiology and factors influencing disease spread. It also outlines management strategies for stem rust including growing resistant varieties and chemical control methods.
Systemic acquired resistance (SAR) is a whole-plant immune response that is activated upon localized infection by a pathogen. It provides long-lasting, broad-spectrum resistance against secondary infections. SAR involves the production of mobile signaling molecules like methyl salicylate, azelaic acid, and glycerol-3-phosphate in infected tissues that activate defenses in distant, uninfected tissues. This results in increased expression of pathogenesis-related proteins and other defenses. The NPR1 protein is a master regulator of the SAR response.
The document discusses the role of enzymes, toxins, and growth regulators in plant pathology and disease development. It defines plant pathology and describes how diseases develop through a complex process influenced by environmental factors and stress. The summary is:
1) Plant pathology studies plant diseases and their causes and controls. Disease develops through interactions between pathogens, hosts, and the environment.
2) Key stages of disease development include inoculation, penetration, infection, pathogen growth and reproduction, and dissemination. Disease occurs when conditions are suitable for the pathogen but not the host.
3) Factors like temperature, moisture, light, soil properties, and wind influence disease development by affecting the pathogen, host, or their interaction. Understanding
This document discusses how plant pathogens cause disease in plants. It explains that pathogens produce enzymes and other substances that allow them to degrade the structural barriers in plant cell walls like cutin, cellulose, pectin, and lignin. This allows the pathogens to enter plant tissues and obtain nutrients. It provides examples of specific enzymes produced by different pathogenic fungi, bacteria, and nematodes to degrade wax, cutin, cellulose, hemicellulose, pectin, protein, starch, and lipids. Degrading these plant cell wall components weakens plant tissues and interferes with their metabolic processes.
This document discusses principles of disease control in agricultural microbiology. It outlines four main principles: 1) Avoidance/Exclusion to prevent import and spread of pathogens, 2) Eradiation to reduce pathogen amounts, 3) Protection to directly protect plants from infection, and 4) Resistant varieties that hinder pathogen development. Specific control methods are described under each principle, including quarantine, sanitation, crop rotation, biological and chemical controls, and genetic engineering to develop resistant varieties.
The document discusses host-parasite relationships and the mechanisms of plant infection. It covers:
1. How fungi obtain food from host plants through haustoria and establish close connections.
2. The definition of host and parasite. Host-parasite relationships affect each other's growth and metabolism.
3. The mechanisms of infection include spores contacting hosts, germ tubes attaching and penetrating tissues using enzymes, and hyphae entering and spreading within host tissues. Pathogens can enter through natural openings or wounds.
B.sc agriculture i principles of plant pathology u 1.3 introduction to plant ...Rai University
The infection process of plant pathogens can be divided into three phases: pre-entry, entry, and colonization. In pre-entry, a spore must germinate and find the host. Entry involves the pathogen penetrating the plant surface directly or through openings. Colonization establishes a parasitic relationship where the pathogen feeds within host tissues as either a biotroph, necrotroph, or hemibiotroph. Successful infection depends on the pathogen, host, and environment, and disrupts various plant processes.
Plant diseases are caused by various pathogens including insects, bacteria, fungi, nematodes, viruses and phytoplasmas. Symptoms include tissue death, wilting, abnormal growth and discolouration. Pathogen survival depends on dispersal mechanisms like air, soil, water, seeds or vectors. Continued infection requires repeating infection cycles. Discontinuous cycles involve epiphytic, saprophytic or resting phases. Inoculum is dispersed as primary or secondary types. Infection involves pathogen germination, penetration structures, and host entry. Colonization differs between biotrophs and necrotrophs. Pathogen presence affects host physiology like respiration, photosynthesis, growth and development. Plant defenses include structural barriers and biochemical
Environment is the factors surrounding plants from heat - Humidity - light - soil ...., and these factors may help the spread of the disease and the incidence and severity of the disease if it is suitable for the growth and reproduction of pathogens or work to increase the resistance to diseases and the disease does not occur if it is suitable for the growth of host plants .Plant disease is only an interaction between the three pillars of the disease triangle
(host plant - pathogen - environmental conditions).
The document summarizes the infection process of pathogens in plants. It describes the three phases of infection as pre-entry, entry, and colonization. In pre-entry, spores must germinate and find entry points like stomata or wounds. During entry, pathogens use specialized structures or enzymes to penetrate the plant surface. In colonization, pathogens establish relationships as biotrophs, necrotrophs, or hemibiotrophs and infect tissues, altering plant physiology through impacts on processes like respiration, photosynthesis, and nutrient transport.
The document summarizes the infection process of pathogens in plants. It describes the three phases of infection as pre-entry, entry, and colonization. Pre-entry involves spore germination and finding a host. Entry can occur through natural openings like stomata or wounds. Colonization establishes a parasitic relationship, with some pathogens living among living cells and others killing cells first. Successful infection requires a pathogen gaining entry and colonizing the host.
This document provides information about the biological management of fungal seed-borne pathogens through bioagents. It discusses seed-borne pathogens and diseases and their importance. It defines bioagents and describes their ideal characteristics as well as their modes of action including competition, antibiosis, mycoparasitism, induced systemic resistance, and siderophore production. The document outlines different delivery systems for bioagents, including seed treatment, seed bio-priming, soil amendment, and soil inoculation. It provides details on seed treatment and seed bio-priming methods.
A brief Power Point Presentation on disease cycle for students about their academics on professional level.
Content for this compilation (Power Point Presentation) was collected from Different sources: Internet, books, social media, research papers, websites etc. and acknowledged all these sources to provide such a helpful content.
This Presentation was prepared and presented during Bachelors In Agriculture (Session 2014-2018) at "University College of Agriculture and Environmental Sciences, Baghdad-ul-Jadeed Campus, The Islamia University of Bahawalpur (Pakistan)" as an Assignment on the topic of "The Disease Cycle" with the collaboration of Student fellows Muhammad Amir Shehzad and Muhammad Farhan.
I hope, content might be helpful for student on academic level.
Best Regards
Muhammad Raza Ullah Tariq
1) The document presents information on seed-borne fungi, including their definition as fungi dispersed in association with host seeds.
2) Seed-borne fungi can directly affect grain quality through growth and metabolites, and were classified as either field fungi invading before harvest or storage fungi developing after harvest.
3) Common storage fungi genera include Aspergillus, Penicillium, Rhizopus, Sclerotium and Fusarium. Detection of seed-borne fungi requires placing seed samples on culture media to encourage fungal growth.
Plants have several defense mechanisms against pathogens. These include morphological barriers like waxes and hairs that prevent infection. Physiological defenses include preformed chemicals like phenols and induced responses like phytoalexins and lignin production. Genetic defenses can involve single genes for resistance but are often polygenic. Together these morphological, physiological and genetic defenses help plants resist or tolerate infection from pathogens.
Detailed description on the mode of actions of various phytoalexins, mechanisms involved phtyoalexin formation, various types of phytoalexins, its functions
Plants have both pre-existing and induced defense mechanisms against pathogens. Pre-existing defenses include structural barriers like the cuticle, cell walls, and natural openings. Biochemical pre-existing defenses include a lack of recognition factors for pathogens and an absence of receptors for pathogen toxins. When a plant is challenged by a pathogen, it induces additional structural defenses like cork layers and gum deposition. Induced biochemical defenses include the hypersensitive response, which causes cell death around the infection site, production of antimicrobial compounds, and detoxification of pathogen toxins. Both pre-existing and induced defenses help plants resist pathogen infection and disease development.
This document discusses the structural and biochemical defense mechanisms in plants against pathogens. It begins by introducing that plants lack an immune system like animals but have developed defenses to detect and prevent extensive damage from invading organisms. It then describes structural defenses like waxes, thick cuticles and cell walls that act as pre-existing barriers, as well as post-infection responses like cork layer formation. Biochemical defenses include pre-existing inhibitors and phenolic compounds, as well as induced responses like phytoalexins - toxic antimicrobial substances produced after infection. Overall, the document provides an overview of the key physical and chemical defenses plants have evolved to protect against various fungi, bacteria, viruses and other pathogens.
DEFENCE MECHANISM IN PLANTS AGAINST PATHOGENS (STRUCTURAL & BIOCHEMICAL) ansarishahid786
Plants have both structural and biochemical defense mechanisms against pathogens. Structural defenses include pre-existing traits like thick cuticles and presence of thick-walled cells, as well as induced responses like formation of cork layers and tyloses after infection. Biochemical defenses include pre-existing inhibitory compounds and enzymes, as well as induced responses like phytoalexins, hypersensitive response, and transgenic production of plantibodies after pathogen detection. Together these defenses provide multiple layers of protection against the wide variety of fungi, bacteria, viruses and other pathogens that plants encounter.
a detailed description of structural and biochemical mechanisms and importance of phytoalexins in plants and different types of phytoalexins produced the plants and its functions and importance in plant defense mechanism
This document discusses the different types of damage insects can inflict on plants. It is divided into several sections:
1) Direct effects of feeding by chewing and sucking insects. Chewing insects cause damage like holes, notches and defoliation. Sucking insects cause chlorosis, silvering, and hopper burn.
2) Indirect effects like making harvest difficult, reducing quality, and spreading disease.
3) Injury by internal feeders like borers, worms, leaf miners and gall insects.
4) Injury to underground parts by root feeders.
5) Injury to stored products which can continue from field or storage attacks.
Various examples are given for
Citrus canker is a bacterial disease caused by the bacterium Xanthomonas citri, producing lesions and cankers on citrus plants.
Cankers are open wounds or dead tissue surrounded by living tissues.
The disease was first reported in Japan in 1904.
It is a serious disease and is worldwide in distribution.
It is particularly serious in India, China, Japan and Java.
In 1915, Hesse first established the bacterial nature of the disease and described the organism as Pseudomonas citri.
Breed et al (1948) included it under Xanthomonas citri.
The Material is Useful for School and Undergraduate students.
This document discusses the infection process of pathogens. It describes the process as having three phases: pre-entry, entry, and colonization. The pre-entry phase includes inoculation, spore germination, and growth on the plant surface. Pathogens must breach barriers to gain entry, which can occur through direct penetration, formation of specialized structures, or natural openings. Successful infection depends on overcoming environmental and plant defenses at each stage.
This document provides information about the genus Erwinia and several pathogenic species that cause diseases in crop plants. It discusses the characteristics of Erwinia bacteria, including their microscopic appearance as gram-negative rods. It then describes several important plant pathogenic Erwinia species and the diseases they cause, including Erwinia amylovora which causes fire blight in apple and pear, and Erwinia carotovora which causes soft rot in vegetables. For each pathogen, it covers topics like symptoms, disease cycle, transmission, and management approaches.
Similar to Mode of entry of bacteria in plants. (20)
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
Or: Beyond linear.
Abstract: Equivariant neural networks are neural networks that incorporate symmetries. The nonlinear activation functions in these networks result in interesting nonlinear equivariant maps between simple representations, and motivate the key player of this talk: piecewise linear representation theory.
Disclaimer: No one is perfect, so please mind that there might be mistakes and typos.
dtubbenhauer@gmail.com
Corrected slides: dtubbenhauer.com/talks.html
Nucleophilic Addition of carbonyl compounds.pptxSSR02
Nucleophilic addition is the most important reaction of carbonyls. Not just aldehydes and ketones, but also carboxylic acid derivatives in general.
Carbonyls undergo addition reactions with a large range of nucleophiles.
Comparing the relative basicity of the nucleophile and the product is extremely helpful in determining how reversible the addition reaction is. Reactions with Grignards and hydrides are irreversible. Reactions with weak bases like halides and carboxylates generally don’t happen.
Electronic effects (inductive effects, electron donation) have a large impact on reactivity.
Large groups adjacent to the carbonyl will slow the rate of reaction.
Neutral nucleophiles can also add to carbonyls, although their additions are generally slower and more reversible. Acid catalysis is sometimes employed to increase the rate of addition.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
ESPP presentation to EU Waste Water Network, 4th June 2024 “EU policies driving nutrient removal and recycling
and the revised UWWTD (Urban Waste Water Treatment Directive)”
Phenomics assisted breeding in crop improvementIshaGoswami9
As the population is increasing and will reach about 9 billion upto 2050. Also due to climate change, it is difficult to meet the food requirement of such a large population. Facing the challenges presented by resource shortages, climate
change, and increasing global population, crop yield and quality need to be improved in a sustainable way over the coming decades. Genetic improvement by breeding is the best way to increase crop productivity. With the rapid progression of functional
genomics, an increasing number of crop genomes have been sequenced and dozens of genes influencing key agronomic traits have been identified. However, current genome sequence information has not been adequately exploited for understanding
the complex characteristics of multiple gene, owing to a lack of crop phenotypic data. Efficient, automatic, and accurate technologies and platforms that can capture phenotypic data that can
be linked to genomics information for crop improvement at all growth stages have become as important as genotyping. Thus,
high-throughput phenotyping has become the major bottleneck restricting crop breeding. Plant phenomics has been defined as the high-throughput, accurate acquisition and analysis of multi-dimensional phenotypes
during crop growing stages at the organism level, including the cell, tissue, organ, individual plant, plot, and field levels. With the rapid development of novel sensors, imaging technology,
and analysis methods, numerous infrastructure platforms have been developed for phenotyping.
1. MODE OF ENTRY OF BACTERIAL
PLANT PATHOGENS
COURSE TEACHER
Dr. PARTHASARATHY S
Asst. Professor (Plant Pathology)
STUDENT
Mr. JEYARAJESH K
ID. NO. 2017021094.
COLLEGE OF AGRICULTURAL TECHNOLOGY
(Affiliated to Tamil Nadu Agricultural University, Coimbatore-3)
Kullapuram (Po),ViaVaigai Dam, Theni-625 562
2. MODE OF ENTRY OF PLANT
PATHOGENS
Unlike fungal pathogens, bacteria are incapable of
mechanically penetrating the cutinized plant tissues,
cuticle, periderm, etc. Since the ability to form
appressoria is lacking in them. The ways of gaining
entry into the plants are by passive/indirect
method(Through openings).
4. Some of the mode of entry of
bacteria in plants.
= Entry through stomata.
= Entry through hydathodes.
= Entry through floral parts.
= Entry through Insect Wounds.
= Entry through Wounds.
= Entry through lenticels
5. Entry through stomata
Stomata are the natural openings present in large numbers on the
lower surface of the leaf which open during day time and more or
less closed at night for gaseous exchange. Bacteria use this natural
opening (stomata) as the way of entry into the plants.
E.g:
1. Pseudomonas tabaci causing wild fire of tobacco.
2. Xanthomonas Phaseoli causing bean blight.
3. Xanthomonas Campestris causing black rot of cabbage.
Fig 2: Wildfire of tobacco
7. Entry through hydathodes
Hydathodes are the pores at the leaf margin, which are continuous
with the xylem. Under particularly humid condition, droplets of xylem
fluid emerge at the surface of the leaf where they can be exposed to
pathogenic bacteria.
E.g: The cells of black rot of cabbage, Xanthomonas campestris,
Fig.4 longitudinal
section of leaf apex and
hydathodes.
Fig.5 Black rot of cabbage
8. Entry through floral parts
Some bacteria use the openings of floral parts especially
nectarthodes (nectar opening)
E.g:
The fire blight bacterium, Erwinia amylovora, enters the
floral parts through the special nectar producing cells present system.
on host flowers, Erwinia amylovora first multiplies on the
stigmatic surface. At high humidity, the bacteria enter the host flower
tissue through the nectarthodes located in the floral cup.
9. Entry through Insect Wounds
The entry through a wound does not require the formation of specialized
structures. some bacteria take the advantage of wounds caused by the insects
attack on plants. By the openings caused by the insects are utilized for the
entry of bacteria.
E. g: Crown gall of fruit trees and wilt of cucumber.
Fig 6:Wilt of cucumber
10. Entry through Wounds
During various cultivation operations and while harvest, transport
and storage, injuries to various plants parts are caused. Many
bacteria present in vicinity enter the host tissue.
E .g: Erwinia spp. causing soft rot of vegetables.
Agrobacterium tumefaciens causing crown gall of fruit trees.
11. Entry through lenticels
Lenticels are the raised pores that allow gas exchange across the bark
of woody plants.
E.g: The potato scab organism, Streptomyces scabies, gains entry into
the tubers through lenticels.
Fig 8: cross sectional view of lenticelsFig 7.
12. Reference:
Dr.Alice D, Dr.Jeyalakshmi C, Dr.Krishnamoorthy AS and
Dr.Karthikeyan M, 2017. Fundamentals of plant pathology,
A.C.Publication, Coimbatore
http://www.apsnet.org/edcenter/intropp/pathogengroups/pages
/bacteria.aspx
http://www.agriinfo.in/default.aspx