Autophagy is a process in which cells degrade and recycle cellular components. The document discusses autophagy in crop plants, including the history and discovery of autophagy genes, the autophagy machinery and mechanisms, and functions of autophagy in processes like leaf senescence, seed development, and stress responses. It also explores the role of autophagy in plant-pathogen interactions and future research prospects. Manipulating autophagy through increased expression of autophagy genes has potential for agricultural benefits like higher yield and stress tolerance in crop plants.
Autophagy and its role in plants - By Tilak I S, Dept. of Biotechnology, UASD.Tilak I S
Autophagy (Macroautophagy) a term from the Greek ‘auto’ (self) and ‘phagein’ (to eat), is a highly regulated cellular degradation and recycling process, conserved from yeast to more complex eukaryotes. The process involves sequestration of the cytoplasm into double-membrane vesicles called autophagosomes, which subsequently fuse with lysosomes or vacuoles. The products of autophagic degradation of intracellular material are exported from lysosomes into the cytoplasm where they are recycled (Tang et al., 2018).
Autophagy is activated during various extracellular or intracellular factors such as nutrients deprivation, drought, stresses, and pathogenic invasion to degrade damaged, denatured, and aggregated proteins (Floyd et al., 2015). The mechanism of autophagy induction and regulation is carried out by TOR (Target of Rapamycin) complex and a number of autophagy related genes (ATGs) and proteins which have been identified in higher eukaryotes including yeasts, mammals, and plants (arabidopsis, rice, wheat, tomato and maize etc.) (Ryabovol and Minibayeva., 2016). In plants autophagy is essential for various physiological processes like growth and development, elimination of toxic compounds from the plants Eg: ROS (reactive oxygen species), involved in programmed cell death, nutrients recycling under detrimental environmental factors. Li et al. (2015) transferred an autophagy-related gene, SiATG8a, from foxtail millet to arabidopsis. Through expression profile analyses demonstrated that SiATG8a expression was induced by both drought and nitrogen starvation and over-expression of SiATG8a improved tolerance to nitrogen starvation and drought stress in transgenic Arabidopsis.
The study of autophagy in crop species has been expanding rapidly. Functions of autophagy in development, abiotic stress responses and plant–microbe interactions have been deciphered in various species (Kabbage et al., 2013). New findings such as the involvement of autophagy in reproductive development are increasing our understanding of autophagy but much work is still needed. One interesting topic that warrants more attention is the role of autophagy in organs or tissues that are specifically present in certain crops, for example fruits and nodules.
Considering its importance in development and stress responses, autophagy is a promising target to manipulate for agricultural benefits like higher yield. Increased expression of ATG genes may be valuable in agricultural applications, as this can confer a number of benefits to plants, including enhanced growth, higher yield and increased stress tolerance.
Role of Autophagy in Plant-Pathogen interaction.pptxVajrammaBoggala
Autophagy is a conserved vacuole/lysosome-mediated degradation pathway for clearing and recycling cellular components including cytosol, macromolecules and dysfunctional organelles. The autophagy pathway not only maintains cellular homeostasis, but also modulates the host’s cellular response to pathogen infection. In recent years, it has emerged to play important roles in plant-pathogen interactions and acts as a powerful tool to defend against pathogen infection in plants. Double-membrane vesicles, termed autophagosomes, deliver selectively trapped pathogen cargo via specific Autophagy receptors to the vacuole/lysosome for degradation. However, in an ongoing evolutionary arms race, pathogens have acquired the potent ability to hijack and manipulate the autophagy machinery of plants to promote pathogenesis against autophagy-dependent resistance. Despite these findings, the complex interplay of autophagy activities, pathogen virulence factors, and host defense pathways in disease development remain poorly understood. Together it can be assumed that the manipulation of autophagy pathways for the development of disease-resistant crops with increased yields, agricultural efficiency, and minimum post-harvest losses is now feasible and may play a significant role in sustaining agriculture in changing climatic scenarios
1. The document discusses the genome sequencing of bread wheat (Triticum aestivum). It summarizes that the 17 Gb draft sequence was organized by individual chromosome arms and identified over 123,000 gene loci that were evenly distributed. Comparative analysis with diploid relatives found high conservation with limited gene loss.
2. Characterization of chromosome 3B found it contained over 5,300 genes, with gene density, expression and function partitioning along the chromosome. Wheat genome plasticity was demonstrated through gene adaptation involving intra-chromosomal duplication and transposable elements.
3. Analysis of the wheat grain transcriptome identified distinct co-expression clusters in the endosperm with some tissue-specific and stage-dependent
Cell death, also known as programmed cell death (PCD), is an important process in multicellular organisms whereby cells undergo an regulated death process. There are three main types of cell death - apoptosis, necrosis, and autophagy. Apoptosis is a tightly regulated form of cell death that plays a key role in development and homeostasis. Necrosis is unregulated cell death that results in inflammation. PCD is important in plants for processes like formation of xylem vessels, senescence, and the hypersensitive response to pathogens. Many pathogens have evolved ways to suppress PCD to promote infection.
GENOMICS
Genomics is the study of all genes in an organism, also known as its genome. Genomics includes identifying the specific building blocks of all the genes in a cell, mapping their location in relation to the rest of the DNA, and studying the function of those genes or combination of those genes.
Types of Genomics :
1. Structural Genomics
2. Comparative Genomics
3.Functional Genomics
4. Epigenomics
5. Metagenomics
6. Pharmacogenomics
7. Mutation Genomics.
PROTEOMICS : (PROTEin in complement to genOME)
Proteomics is the study of proteome [Proteome is a protein molecule that interacts to give the cell its individual character]. Proteomics is a subset of functional genomics.
The proteome of a cell is all the proteins expressed by its genome. The proteome is of intense interest to investigators because proteins are the major functional components of the cell.
Proteomics is the study of proteins in order to revolutionize the understanding of cell behaviour and disease.
1. It studies the translation of process of RNA into proteins as well as the overall process of DNA into proteins.
2. It studies the diseases through proteins because disease process manifest themselves at the level of protein activity.
3. Most drugs act by targeting proteins or protein receptors, so Proteomics is important in new generation of drugs.
4. Proteins are more complex than genes because they can be modified after formation.
5. Proteomics is the qualitative and quantitative comparison of proteomes under different conditions to further unravel biological processes.
6. Proteomics can use analysis techniques to determine all of the post translational modifications that proteins undergo and therefore determine what makes a diseased or mutant protein different from a normal protein.
Proteins are fundamental components of all living cells. Proteins help us digest our food, fight infections, control body chemistry, keep our bodies function smoothly. Identifying a proteins’ shape or structure is key to understanding its biological function and its role in health and disease.
This document summarizes information about programmed cell death (PCD) in plants. It discusses how PCD is essential for plant development and defense. There are two main classes of plant PCD - developmental and defensive. Developmental PCD regulates cell division and organ development, while defensive PCD helps destroy infected cells and activate systemic resistance. PCD is controlled by genetically regulated proteases like metacaspases and vacuolar processing enzymes. Hypersensitive response is a form of defensive PCD that rapidly kills cells at infection sites. Necrosis differs from PCD in that it is an unregulated form of cell death caused by injury rather than an active suicide process.
- 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.
Marker free transgenic crops can be generated using several strategies to avoid issues with marker genes. Selectable marker genes allow selection of transformed cells but their products may be undesirable in food. Strategies include co-transformation using two plasmids without linking marker and trait genes, replacing selectable markers with screenable markers, and excising the selectable marker from the genome after selection using site-specific recombination, transposition, or homologous recombination. Case studies demonstrate applying these strategies successfully in tobacco and mustard to generate marker free transgenic plants.
Autophagy and its role in plants - By Tilak I S, Dept. of Biotechnology, UASD.Tilak I S
Autophagy (Macroautophagy) a term from the Greek ‘auto’ (self) and ‘phagein’ (to eat), is a highly regulated cellular degradation and recycling process, conserved from yeast to more complex eukaryotes. The process involves sequestration of the cytoplasm into double-membrane vesicles called autophagosomes, which subsequently fuse with lysosomes or vacuoles. The products of autophagic degradation of intracellular material are exported from lysosomes into the cytoplasm where they are recycled (Tang et al., 2018).
Autophagy is activated during various extracellular or intracellular factors such as nutrients deprivation, drought, stresses, and pathogenic invasion to degrade damaged, denatured, and aggregated proteins (Floyd et al., 2015). The mechanism of autophagy induction and regulation is carried out by TOR (Target of Rapamycin) complex and a number of autophagy related genes (ATGs) and proteins which have been identified in higher eukaryotes including yeasts, mammals, and plants (arabidopsis, rice, wheat, tomato and maize etc.) (Ryabovol and Minibayeva., 2016). In plants autophagy is essential for various physiological processes like growth and development, elimination of toxic compounds from the plants Eg: ROS (reactive oxygen species), involved in programmed cell death, nutrients recycling under detrimental environmental factors. Li et al. (2015) transferred an autophagy-related gene, SiATG8a, from foxtail millet to arabidopsis. Through expression profile analyses demonstrated that SiATG8a expression was induced by both drought and nitrogen starvation and over-expression of SiATG8a improved tolerance to nitrogen starvation and drought stress in transgenic Arabidopsis.
The study of autophagy in crop species has been expanding rapidly. Functions of autophagy in development, abiotic stress responses and plant–microbe interactions have been deciphered in various species (Kabbage et al., 2013). New findings such as the involvement of autophagy in reproductive development are increasing our understanding of autophagy but much work is still needed. One interesting topic that warrants more attention is the role of autophagy in organs or tissues that are specifically present in certain crops, for example fruits and nodules.
Considering its importance in development and stress responses, autophagy is a promising target to manipulate for agricultural benefits like higher yield. Increased expression of ATG genes may be valuable in agricultural applications, as this can confer a number of benefits to plants, including enhanced growth, higher yield and increased stress tolerance.
Role of Autophagy in Plant-Pathogen interaction.pptxVajrammaBoggala
Autophagy is a conserved vacuole/lysosome-mediated degradation pathway for clearing and recycling cellular components including cytosol, macromolecules and dysfunctional organelles. The autophagy pathway not only maintains cellular homeostasis, but also modulates the host’s cellular response to pathogen infection. In recent years, it has emerged to play important roles in plant-pathogen interactions and acts as a powerful tool to defend against pathogen infection in plants. Double-membrane vesicles, termed autophagosomes, deliver selectively trapped pathogen cargo via specific Autophagy receptors to the vacuole/lysosome for degradation. However, in an ongoing evolutionary arms race, pathogens have acquired the potent ability to hijack and manipulate the autophagy machinery of plants to promote pathogenesis against autophagy-dependent resistance. Despite these findings, the complex interplay of autophagy activities, pathogen virulence factors, and host defense pathways in disease development remain poorly understood. Together it can be assumed that the manipulation of autophagy pathways for the development of disease-resistant crops with increased yields, agricultural efficiency, and minimum post-harvest losses is now feasible and may play a significant role in sustaining agriculture in changing climatic scenarios
1. The document discusses the genome sequencing of bread wheat (Triticum aestivum). It summarizes that the 17 Gb draft sequence was organized by individual chromosome arms and identified over 123,000 gene loci that were evenly distributed. Comparative analysis with diploid relatives found high conservation with limited gene loss.
2. Characterization of chromosome 3B found it contained over 5,300 genes, with gene density, expression and function partitioning along the chromosome. Wheat genome plasticity was demonstrated through gene adaptation involving intra-chromosomal duplication and transposable elements.
3. Analysis of the wheat grain transcriptome identified distinct co-expression clusters in the endosperm with some tissue-specific and stage-dependent
Cell death, also known as programmed cell death (PCD), is an important process in multicellular organisms whereby cells undergo an regulated death process. There are three main types of cell death - apoptosis, necrosis, and autophagy. Apoptosis is a tightly regulated form of cell death that plays a key role in development and homeostasis. Necrosis is unregulated cell death that results in inflammation. PCD is important in plants for processes like formation of xylem vessels, senescence, and the hypersensitive response to pathogens. Many pathogens have evolved ways to suppress PCD to promote infection.
GENOMICS
Genomics is the study of all genes in an organism, also known as its genome. Genomics includes identifying the specific building blocks of all the genes in a cell, mapping their location in relation to the rest of the DNA, and studying the function of those genes or combination of those genes.
Types of Genomics :
1. Structural Genomics
2. Comparative Genomics
3.Functional Genomics
4. Epigenomics
5. Metagenomics
6. Pharmacogenomics
7. Mutation Genomics.
PROTEOMICS : (PROTEin in complement to genOME)
Proteomics is the study of proteome [Proteome is a protein molecule that interacts to give the cell its individual character]. Proteomics is a subset of functional genomics.
The proteome of a cell is all the proteins expressed by its genome. The proteome is of intense interest to investigators because proteins are the major functional components of the cell.
Proteomics is the study of proteins in order to revolutionize the understanding of cell behaviour and disease.
1. It studies the translation of process of RNA into proteins as well as the overall process of DNA into proteins.
2. It studies the diseases through proteins because disease process manifest themselves at the level of protein activity.
3. Most drugs act by targeting proteins or protein receptors, so Proteomics is important in new generation of drugs.
4. Proteins are more complex than genes because they can be modified after formation.
5. Proteomics is the qualitative and quantitative comparison of proteomes under different conditions to further unravel biological processes.
6. Proteomics can use analysis techniques to determine all of the post translational modifications that proteins undergo and therefore determine what makes a diseased or mutant protein different from a normal protein.
Proteins are fundamental components of all living cells. Proteins help us digest our food, fight infections, control body chemistry, keep our bodies function smoothly. Identifying a proteins’ shape or structure is key to understanding its biological function and its role in health and disease.
This document summarizes information about programmed cell death (PCD) in plants. It discusses how PCD is essential for plant development and defense. There are two main classes of plant PCD - developmental and defensive. Developmental PCD regulates cell division and organ development, while defensive PCD helps destroy infected cells and activate systemic resistance. PCD is controlled by genetically regulated proteases like metacaspases and vacuolar processing enzymes. Hypersensitive response is a form of defensive PCD that rapidly kills cells at infection sites. Necrosis differs from PCD in that it is an unregulated form of cell death caused by injury rather than an active suicide process.
- 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.
Marker free transgenic crops can be generated using several strategies to avoid issues with marker genes. Selectable marker genes allow selection of transformed cells but their products may be undesirable in food. Strategies include co-transformation using two plasmids without linking marker and trait genes, replacing selectable markers with screenable markers, and excising the selectable marker from the genome after selection using site-specific recombination, transposition, or homologous recombination. Case studies demonstrate applying these strategies successfully in tobacco and mustard to generate marker free transgenic plants.
Regulation of eukaryotic gene expressionMd Murad Khan
The document discusses various mechanisms of regulating gene expression in eukaryotes. It explains that regulation can occur at multiple levels, including DNA, transcription, mRNA processing, and protein synthesis. Key points include: (1) Regulation allows adaptation and cellular differentiation; (2) In eukaryotes, transcription and translation are separated, allowing more complex regulation; (3) Regulation mechanisms include controlling chromatin structure, transcription initiation, mRNA splicing/stability, and protein modifications. Environmental factors like heat and hormones can also induce gene expression changes through transcription factors.
This document summarizes a presentation on using CRISPR-Cas9 for crop improvement. It begins with an introduction to CRISPR-Cas9 and how it is used to edit genomes by removing, adding, or altering DNA sequences. It then discusses the mechanism of the CRISPR-Cas9 complex and how it creates breaks in DNA that are repaired. The document reviews several case studies where CRISPR was used to modify crops, including creating low-gluten wheat and improving rice. It finds that CRISPR can efficiently edit multiple genes simultaneously with few off-target effects. The conclusion states that CRISPR is revolutionizing agriculture by enabling the creation of higher yielding, more resistant crop varieties without transgenes.
This document discusses genes in plants that provide disease resistance. It begins by outlining the plant immune system and the zig-zag model involving PAMP-triggered immunity and effector-triggered immunity. It then describes different classes of plant resistance genes based on their structural features and domains. The document also discusses the functions of resistance genes in signaling plant defenses, and provides examples of resistance genes that have been cloned and provide resistance against various pathogens like fungi, viruses, nematodes, and more.
DNA repair is a collection of processes cells use to identify and correct damage to DNA. There are several types of DNA repair mechanisms, including direct repair, base excision repair, mismatch repair, recombination repair, and SOS repair. DNA repair has advantages of maintaining genetic integrity between generations and preserving individual health, but defects can lead to increased cancer risks and premature aging syndromes.
Assimilation of ammonium ions is the ultimate aim of nitrogen metabolism in plants. this is the source of nitrogen for various organic compounds of structural and functional importance for the living world
Genome editing technologies allow genetic material to be added, removed or altered at specific locations in an organism's genome. Several approaches exist, including zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), CRISPR/Cas9, and base editors. These tools create precise breaks in DNA that can be repaired through non-homologous end joining or homology-directed repair. They enable trait discovery and crop improvement by generating plants with high yield, stress resistance, or other desired properties. While powerful, challenges remain in fully editing complex genomes and reducing off-target mutations.
Programmed cell death in plants by shivanand b. koppadShivanand Koppad
This document discusses programmed cell death (PCD) in plants. It provides definitions of PCD and necrosis, and describes the differences between the two processes. PCD, also called apoptosis, is an actively controlled and genetically regulated process while necrosis is unregulated cell death in response to external stressors. The document outlines the history of studying PCD/apoptosis and discusses PCD pathways, regulators like caspases, and importance in plant development and response to the environment. It also provides a case study on PCD in tomato fruit in response to heat stress.
This document discusses pathogenesis-related (PR) proteins found in plants. It begins with definitions, noting that PR proteins are produced when plants are infected by pathogens and act to decrease susceptibility. It then describes 17 types of PR proteins classified into families based on their properties, with examples like chitinase and glucanase. Mechanisms of action are discussed, such as degrading fungal cell walls. The document concludes by outlining applications for transferring PR protein genes to transgenic plants to engineer resistance against pathogens like fungi and bacteria.
Researchers used RNA interference technology to genetically modify maize kernels for improved nutritional value. They targeted the lysine catabolism pathway by suppressing the LKR/SDH genes through recombinant RNAi. This led to transgenic maize with higher free lysine content. Experiments showed segregated reduction of LKR/SDH expression in mature F1 kernels, with consistent reduction at later developmental stages but normal accumulation earlier. Quantitative analysis confirmed LKR/SDH reduction in both embryo and endosperm, along with decreased LKR activity and increased free lysine and saccharopine levels. The study demonstrated that RNAi can effectively modify lysine metabolism in maize to enhance its nutritional profile.
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.
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.
Viral infections in plants can be controlled through several strategies including using certified seed/plants, controlling weeds that harbor viruses, and insecticide use since most viruses are vector-borne. Transgenic virus resistance involves expressing viral genes including coat proteins, replicases, movement proteins, or antisense RNA to interfere with viral replication or movement. The papaya industry was saved through a transgenic papaya resistant to papaya ringspot virus. While virus resistance holds promise, risks like recombination or heterologous encapsidation must be monitored.
Somaclonal variation refers to genetic variations that can arise during plant tissue culture and regeneration. When plant cells or tissues are cultured in vitro, genetic and epigenetic changes can occur, resulting in phenotypically different regenerated plants (somaclones) compared to the original plant. Somaclonal variation is caused by factors like culture conditions, genotype, explant source, and selection method used. It can generate variations in chromosome structure, number, and gene mutations. Somaclonal variation has been used to develop novel variants with improved traits like disease resistance, abiotic stress tolerance, and altered plant morphology. However, extensive field testing is required to evaluate variants due to possible genetic instability and undesirable effects.
plant pathogen interaction
different types of pathogens
gene for gene hypothesis
direct receptor model
Elicitor receptor model
suppersor repressor model
gaurd hypothesis
This document summarizes information about plastid transformation. Plastids are organelles found in plant cells that perform photosynthesis and store compounds. They have their own circular genome. Plastid transformation involves introducing foreign genes into the plastid genome using homologous recombination. It is preferred over nuclear transformation for traits because it allows high-level transgene expression and containment of transgenes within the plastid. The document discusses chloroplast structure, common vectors, selection markers, traits of interest for transformation including stress tolerance and pharmaceutical production, and limitations of plastid transformation technology.
- β-glucuronidase (GUS) is a commonly used reporter gene in plant molecular biology and genetic engineering to indicate successful introduction of foreign DNA into cells.
- GUS expression can be detected through fluorometric or histochemical assays, allowing visualization of promoter activity, protein localization, and transgenic events.
- The GUS gene is fused to genes of interest, and GUS activity is used to study processes like tissue-specific expression, response to stresses, and transformation efficiency.
- While destructive, GUS is a stable and non-toxic reporter enabling versatile applications in fundamental and applied plant research.
The document summarizes the ABC model of flower development. It discusses (a) the transition from vegetative to reproductive phase controlled by genes like FT, LFY, and SOC1, (b) the formation of inflorescence meristems regulated by genes like WUS and STM that prevent stem cell differentiation, and (c) individual floral organ development governed by meristem identity, organ identity, and cadastral genes. The ABC model specifies floral organ identity through the combinatorial interactions of ABC genes like AP3, PI, AG, and AP2, and D class genes like FBP7 control ovule development. The ABC model is sufficient to convert meristems into flowers and applies broadly across flowering plants.
An overview of agricultural applications of genome editing: Crop plantsOECD Environment
The presentation gives an overview of genome editing applications in relation to crop plants. The aim is to have a better understanding of the specific features of genome editing in comparison with classical breeding and genetic engineering techniques. It will give an overview of some examples of agricultural applications that may be on or close to the market or under research and development. It will also consider the possibility of foreseeing future applications (e.g. variations in CRISPR/Cas applications, DNA-free application, agricultural pest control), if possible.
Molecular mechanisms of Autophagy and its Role in Plant Immunity SystemsMonuj Gogoi
Details of Autophagy Mechanisms and its roles for plant diseases management.
Numbers of papers were selected for the preparation of this presentation. So Thanks to all authors those are published.
The document discusses the molecular mechanism of autophagy and its role in plants. It begins with an introduction to autophagy and discusses landmarks in the discovery of autophagy. It then covers the different classes of autophagy, genes and proteins involved, and the molecular mechanism. This includes discussion of the induction, expansion, and maturation steps. It also discusses selective autophagy and techniques to study autophagy. The document concludes by covering the physiological roles of autophagy in plants, including roles in nutrient starvation, oxidative stress response, development, pathogen response, and programmed cell death.
Regulation of eukaryotic gene expressionMd Murad Khan
The document discusses various mechanisms of regulating gene expression in eukaryotes. It explains that regulation can occur at multiple levels, including DNA, transcription, mRNA processing, and protein synthesis. Key points include: (1) Regulation allows adaptation and cellular differentiation; (2) In eukaryotes, transcription and translation are separated, allowing more complex regulation; (3) Regulation mechanisms include controlling chromatin structure, transcription initiation, mRNA splicing/stability, and protein modifications. Environmental factors like heat and hormones can also induce gene expression changes through transcription factors.
This document summarizes a presentation on using CRISPR-Cas9 for crop improvement. It begins with an introduction to CRISPR-Cas9 and how it is used to edit genomes by removing, adding, or altering DNA sequences. It then discusses the mechanism of the CRISPR-Cas9 complex and how it creates breaks in DNA that are repaired. The document reviews several case studies where CRISPR was used to modify crops, including creating low-gluten wheat and improving rice. It finds that CRISPR can efficiently edit multiple genes simultaneously with few off-target effects. The conclusion states that CRISPR is revolutionizing agriculture by enabling the creation of higher yielding, more resistant crop varieties without transgenes.
This document discusses genes in plants that provide disease resistance. It begins by outlining the plant immune system and the zig-zag model involving PAMP-triggered immunity and effector-triggered immunity. It then describes different classes of plant resistance genes based on their structural features and domains. The document also discusses the functions of resistance genes in signaling plant defenses, and provides examples of resistance genes that have been cloned and provide resistance against various pathogens like fungi, viruses, nematodes, and more.
DNA repair is a collection of processes cells use to identify and correct damage to DNA. There are several types of DNA repair mechanisms, including direct repair, base excision repair, mismatch repair, recombination repair, and SOS repair. DNA repair has advantages of maintaining genetic integrity between generations and preserving individual health, but defects can lead to increased cancer risks and premature aging syndromes.
Assimilation of ammonium ions is the ultimate aim of nitrogen metabolism in plants. this is the source of nitrogen for various organic compounds of structural and functional importance for the living world
Genome editing technologies allow genetic material to be added, removed or altered at specific locations in an organism's genome. Several approaches exist, including zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), CRISPR/Cas9, and base editors. These tools create precise breaks in DNA that can be repaired through non-homologous end joining or homology-directed repair. They enable trait discovery and crop improvement by generating plants with high yield, stress resistance, or other desired properties. While powerful, challenges remain in fully editing complex genomes and reducing off-target mutations.
Programmed cell death in plants by shivanand b. koppadShivanand Koppad
This document discusses programmed cell death (PCD) in plants. It provides definitions of PCD and necrosis, and describes the differences between the two processes. PCD, also called apoptosis, is an actively controlled and genetically regulated process while necrosis is unregulated cell death in response to external stressors. The document outlines the history of studying PCD/apoptosis and discusses PCD pathways, regulators like caspases, and importance in plant development and response to the environment. It also provides a case study on PCD in tomato fruit in response to heat stress.
This document discusses pathogenesis-related (PR) proteins found in plants. It begins with definitions, noting that PR proteins are produced when plants are infected by pathogens and act to decrease susceptibility. It then describes 17 types of PR proteins classified into families based on their properties, with examples like chitinase and glucanase. Mechanisms of action are discussed, such as degrading fungal cell walls. The document concludes by outlining applications for transferring PR protein genes to transgenic plants to engineer resistance against pathogens like fungi and bacteria.
Researchers used RNA interference technology to genetically modify maize kernels for improved nutritional value. They targeted the lysine catabolism pathway by suppressing the LKR/SDH genes through recombinant RNAi. This led to transgenic maize with higher free lysine content. Experiments showed segregated reduction of LKR/SDH expression in mature F1 kernels, with consistent reduction at later developmental stages but normal accumulation earlier. Quantitative analysis confirmed LKR/SDH reduction in both embryo and endosperm, along with decreased LKR activity and increased free lysine and saccharopine levels. The study demonstrated that RNAi can effectively modify lysine metabolism in maize to enhance its nutritional profile.
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.
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.
Viral infections in plants can be controlled through several strategies including using certified seed/plants, controlling weeds that harbor viruses, and insecticide use since most viruses are vector-borne. Transgenic virus resistance involves expressing viral genes including coat proteins, replicases, movement proteins, or antisense RNA to interfere with viral replication or movement. The papaya industry was saved through a transgenic papaya resistant to papaya ringspot virus. While virus resistance holds promise, risks like recombination or heterologous encapsidation must be monitored.
Somaclonal variation refers to genetic variations that can arise during plant tissue culture and regeneration. When plant cells or tissues are cultured in vitro, genetic and epigenetic changes can occur, resulting in phenotypically different regenerated plants (somaclones) compared to the original plant. Somaclonal variation is caused by factors like culture conditions, genotype, explant source, and selection method used. It can generate variations in chromosome structure, number, and gene mutations. Somaclonal variation has been used to develop novel variants with improved traits like disease resistance, abiotic stress tolerance, and altered plant morphology. However, extensive field testing is required to evaluate variants due to possible genetic instability and undesirable effects.
plant pathogen interaction
different types of pathogens
gene for gene hypothesis
direct receptor model
Elicitor receptor model
suppersor repressor model
gaurd hypothesis
This document summarizes information about plastid transformation. Plastids are organelles found in plant cells that perform photosynthesis and store compounds. They have their own circular genome. Plastid transformation involves introducing foreign genes into the plastid genome using homologous recombination. It is preferred over nuclear transformation for traits because it allows high-level transgene expression and containment of transgenes within the plastid. The document discusses chloroplast structure, common vectors, selection markers, traits of interest for transformation including stress tolerance and pharmaceutical production, and limitations of plastid transformation technology.
- β-glucuronidase (GUS) is a commonly used reporter gene in plant molecular biology and genetic engineering to indicate successful introduction of foreign DNA into cells.
- GUS expression can be detected through fluorometric or histochemical assays, allowing visualization of promoter activity, protein localization, and transgenic events.
- The GUS gene is fused to genes of interest, and GUS activity is used to study processes like tissue-specific expression, response to stresses, and transformation efficiency.
- While destructive, GUS is a stable and non-toxic reporter enabling versatile applications in fundamental and applied plant research.
The document summarizes the ABC model of flower development. It discusses (a) the transition from vegetative to reproductive phase controlled by genes like FT, LFY, and SOC1, (b) the formation of inflorescence meristems regulated by genes like WUS and STM that prevent stem cell differentiation, and (c) individual floral organ development governed by meristem identity, organ identity, and cadastral genes. The ABC model specifies floral organ identity through the combinatorial interactions of ABC genes like AP3, PI, AG, and AP2, and D class genes like FBP7 control ovule development. The ABC model is sufficient to convert meristems into flowers and applies broadly across flowering plants.
An overview of agricultural applications of genome editing: Crop plantsOECD Environment
The presentation gives an overview of genome editing applications in relation to crop plants. The aim is to have a better understanding of the specific features of genome editing in comparison with classical breeding and genetic engineering techniques. It will give an overview of some examples of agricultural applications that may be on or close to the market or under research and development. It will also consider the possibility of foreseeing future applications (e.g. variations in CRISPR/Cas applications, DNA-free application, agricultural pest control), if possible.
Molecular mechanisms of Autophagy and its Role in Plant Immunity SystemsMonuj Gogoi
Details of Autophagy Mechanisms and its roles for plant diseases management.
Numbers of papers were selected for the preparation of this presentation. So Thanks to all authors those are published.
The document discusses the molecular mechanism of autophagy and its role in plants. It begins with an introduction to autophagy and discusses landmarks in the discovery of autophagy. It then covers the different classes of autophagy, genes and proteins involved, and the molecular mechanism. This includes discussion of the induction, expansion, and maturation steps. It also discusses selective autophagy and techniques to study autophagy. The document concludes by covering the physiological roles of autophagy in plants, including roles in nutrient starvation, oxidative stress response, development, pathogen response, and programmed cell death.
Molecular control of male fertility for crop hybrid breedingSuresh Antre
Harnessing hybrid vigor or heterosis is a promising approach to tackle the current challenge of sustaining enhanced yield gains of field crops. More than half of the production of major crops such as maize, rice, sorghum, rapeseed, and sunflower comes from hybrid varieties.
Cloning and extracellular expression of recombinant tissue plasminogen activa...bioejjournal
Tissue plasminogen activator (tPA) has noteworthy application in treatment of acute myocardial
infarctions. This study focuses on expression of rt-PA using microbial systems in order to reduce cost
without compromising on quality as an alternative to commercial (rt-PA)produced by using mammalian
host systems. In the present study, Pichia pastoris X-33strain was used as a host with pICZαA expression
vector to obtain extracellular expression of full length tPA gene. Specific primers were designed in such a
way to get native tPA protein sequence in subsequent purification steps. Further, construct pICZαA-tPA
was developed and electroporated into host to achieve stablert-PA gene by achieving genome integration. The transformants were screened for phenotypic characters.Mut+
phenotypic colony named Pichia tPA-3
showed expression of rt-PA at 66 kDa on SDS PAGE. Size Exclusion Chromatography (SEC) was
performed, resulting in product peak at same RT as reference standard. (alteplase).Cloning and expression
of rt-PA was successfully achieved in microbial system. Further process optimization at larger scales will surely provide cost effective alternative to mammalian system forrt-PA production
Cloning and extracellular expression of recombinant tissue plasminogen activa...bioejjournal
This document summarizes research conducted to clone and express recombinant tissue plasminogen activator (rt-PA) using the methylotrophic yeast Pichia pastoris. Specifically, the tissue plasminogen activator gene was cloned into the pICZαA expression vector. This construct was then transformed into Pichia pastoris X33 cells. One transformant, named Pichia tPA-3, showed expression of rt-PA at 66 kDa on SDS-PAGE. Size exclusion chromatography also showed a product peak at the same retention time as a reference tPA standard. Thus, the researchers were able to successfully clone and express rt-PA in the Pichia pastoris system.
Cloning and Extracellular Expression of Recombinant Tissue Plasminogen Activa...bioejjournal
This document summarizes research conducted to clone and express recombinant tissue plasminogen activator (rt-PA) using the methylotrophic yeast Pichia pastoris. Specifically, the full-length tPA gene was amplified by PCR and cloned into the pICZαA expression vector. This construct was then transformed into Pichia pastoris X33 cells. One transformant, named Pichia tPA-3, showed extracellular expression of rt-PA at 66 kDa on SDS-PAGE after induction with methanol over 144 hours. Size exclusion chromatography of samples from this transformant showed a product peak at the same retention time as a reference tPA standard. Thus, the researchers successfully achieved cloning and extracellular expression of
Yoshinori Ohsumi's seminal work in the early 1990s dramatically advanced the understanding of autophagy. Using yeast as a model organism, he identified 15 essential autophagy genes and developed yeast strains that allowed him to discover the first autophagy gene, Atg1. His subsequent cloning and characterization of additional autophagy genes elucidated their protein products and roles in autophagosome formation. This included delineating how stress signals initiate autophagy through the Atg1 kinase complex and phosphatidylinositol 3-kinase complex, and the two ubiquitin-like conjugation systems that promote phagophore extension and autophagosome maturation. Ohsumi
Cloning and Extracellular Expression of Recombinant Tissue Plasminogen Activa...bioejjournal
Tissue plasminogen activator (tPA) has noteworthy application in treatment of acute myocardial
infarctions. This study focuses on expression of rt-PA using microbial systems in order to reduce cost
without compromising on quality as an alternative to commercial (rt-PA)produced by using mammalian
host systems. In the present study, Pichia pastoris X-33strain was used as a host with pICZαA expression
vector to obtain extracellular expression of full length tPA gene. Specific primers were designed in such a
way to get native tPA protein sequence in subsequent purification steps. Further, construct pICZαA-tPA
was developed and electroporated into host to achieve stablert-PA gene by achieving genome integration.
The transformants were screened for phenotypic characters.Mut+
phenotypic colony named Pichia tPA-3
showed expression of rt-PA at 66 kDa on SDS PAGE. Size Exclusion Chromatography (SEC) was
performed, resulting in product peak at same RT as reference standard. (alteplase).Cloning and expression
of rt-PA was successfully achieved in microbial system. Further process optimization at larger scales will
surely provide cost effective alternative to mammalian system forrt-PA production.
CLONING AND EXTRACELLULAR EXPRESSION OF RECOMBINANT TISSUE PLASMINOGEN ACTIVA...bioejjournal
Tissue plasminogen activator (tPA) has noteworthy application in treatment of acute myocardial infarctions. This study focuses on expression of rt-PA using microbial systems in order to reduce cost
without compromising on quality as an alternative to commercial (rt-PA)produced by using mammalian host systems. In the present study, Pichia pastoris X-33strain was used as a host with pICZαA expression vector to obtain extracellular expression of full length tPA gene. Specific primers were designed in such a way to get native tPA protein sequence in subsequent purification steps
The document summarizes a study that identified potent and selective inhibitors of the Plasmodium falciparum M18 aspartyl aminopeptidase (PfM18AAP) enzyme via high-throughput screening. PfM18AAP plays an important role in malaria parasite growth and is a potential drug target. A fluorescence-based assay was developed to screen over 292,000 compounds, identifying two structurally related compounds that potently and selectively inhibited PfM18AAP in the low micromolar range. Both compounds were found to be noncompetitive inhibitors of PfM18AAP and inhibited malaria parasite growth, demonstrating their potential as antimalarial therapies.
Presence of genetically modified organism genes in carica papaya, glycine max...valrivera
This document summarizes a study that aimed to detect the presence of genetically modified organism (GMO) genes in fruits from four plants: papaya, soybean, corn, and wheat. DNA was extracted from samples of each fruit and tested via polymerase chain reaction (PCR) and gel electrophoresis to detect two common GMO markers - the 35S promoter and NOS terminator. The results were inconclusive due to DNA degradation and possible human errors during experiments. As such, the study was unable to determine if the fruits contained GMO genes.
Autophagy is a self-digesting mechanism in which cells form double-membrane vesicles called autophagosomes that encapsulate cytoplasm, organelles, and proteins. These autophagosomes then fuse with lysosomes for degradation of the encapsulated materials. There are three main types of autophagy: microautophagy, chaperone-mediated autophagy, and macroautophagy. Macroautophagy involves autophagosome formation through a complex process involving 16 autophagy-related proteins and two ubiquitin-like conjugation systems. Once completed, autophagosomes fuse with lysosomes for degradation of their contents. Autophagy plays an important role
Epigenetics involves changes in gene expression that do not involve changes to the underlying DNA sequence. Examples of epigenetics include histone modifications and DNA methylation, which regulate gene expression through alterations to chromatin structure. Histone methylation involves the addition of methyl groups to histone tails by methyltransferases and regulates gene expression by promoting or blocking the binding of transcription factors. While histone methylation does not change charge or nucleosome interactions, it creates binding sites that regulate chromatin condensation and mobility to control gene expression.
The document summarizes recent research on the role of the phytohormone indole-3-acetic acid (IAA) in microbial and microorganism-plant signaling. It discusses that diverse bacterial species can produce IAA through different biosynthesis pathways, with redundancy widespread. Interactions between IAA-producing bacteria and plants can result in outcomes ranging from pathogenesis to phytostimulation. The review highlights that bacteria use IAA to interact with plants during colonization, including phytostimulation and circumventing plant defenses. Additionally, recent evidence indicates IAA can act as a signaling molecule in bacteria and directly impact bacterial physiology.
Proteomic analysis of the interaction between the plant growth promoting fhiz...kys9723331
Plant growth-promoting rhizobacteria (PGPR) facilitate the plant growth and enhance their
induced systemic resistance (ISR) against a variety of environmental stresses. In this study,
we carried out integrative analyses on the proteome, transcriptome, and metabolome to investigate
Arabidopsis root and shoot responses to the well-known PGPR strain Paenibacillus
polymyxa (P. polymyxa) E681. Shoot fresh and root dry weights were increased, whereas root
length was decreased by treatment with P. polymyxa E681. 2DE approach in conjunction
with MALDI-TOF/TOF analysis revealed a total of 41 (17 spots in root, 24 spots in shoot)
that were differentially expressed in response to P. polymyxa E681. Biological process- and
molecular function-based bioinformatics analysis resulted in their classification into seven different
protein groups. Of these, 36 proteins including amino acid metabolism, antioxidant,
defense and stress response, photosynthesis, and plant hormone-related proteins were upregulated,
whereas five proteins including three carbohydrate metabolism- and one amino
acid metabolism-related, and one unknown protein were down-regulated, respectively. A good
correlation was observed between protein and transcript abundances for the 12 differentially
expressed proteins during interactions as determined by qPCR analysis. Metabolite analysis
using LC-MS/MS revealed highly increased levels of tryptophan, indole-3-acetonitrile (IAN),
indole-3-acetic acid (IAA), and camalexin in the treated plants. Arabidopsis plant inoculated
P. polymyxa E681 also showed resistance to Botrytis cinerea infection. Taken together these
results suggest that P. polymyxa E681 may promote plant growth by induced metabolism and
activation of defense-related proteins against fungal pathogen.
Presence of genetically modified organism genes in carica papaya, glycine max...Carlos Santos Perez
The document summarizes a study that aimed to detect the presence of genetically modified organism (GMO) genes in fruits from four plants - Carica papaya, Glycine max, Triticum spp., and Zea mays - using polymerase chain reaction (PCR) and gel electrophoresis. DNA was extracted from samples of each fruit and tested with PCR for the presence of common GMO markers. Gel electrophoresis revealed bands indicating the presence of plant DNA but unclear or missing bands for the GMO markers, likely due to DNA degradation. The results did not confirm or deny the hypothesis due to errors affecting the experiment.
Roles of autophagy in relation to mitochondrial stress responses of HeLa cell...Sebastian Garcia Ortega
This document discusses a study investigating the roles of autophagy in relation to mitochondrial stress responses of HeLa cells to lamellarin cytotoxicity. The study uses CRISPR-Cas9 gene editing to knockout autophagy genes in cervical cancer cells. Immunoblotting and immunofluorescence are then used to recognize apoptotic molecules and observe the effects on apoptosis activation. The results and discussion sections analyze how defects in autophagy machinery affect mitophagy and the rate of apoptosis. The conclusions state that further study of lamellarin's effects on cancer cells could lead to breakthrough cancer treatments, and investigating autophagy mechanisms may reveal new discoveries for treating diseases.
Growth Pattern, Molecular Identification and Bio molecules Analysis of FOMITO...journal ijrtem
Abstract : Fomitopsis feei, a brown rot fungus is identified tentatively using morphological characteristics and confirmed phylogenetically by 28S rDNA analysis and sequence was submitted in EMBL Nucleotide Sequence Database. Its growth pattern was studied on eight different solid media and found to be good on Malt extract agar medium. Biomolecules such as proteins and lipid were screened qualitatively and estimated quantitatively. Aminoacid analysis by chromatography and fatty acid analysis by FAME were also done and revealed that tryptophan (20.53%), valine (20.51%) and cis-linoleic acid (43.38%) and palmetic acid (17.88%) were in high percentage.
Key words : Fomitopsis feei, growth, molecular identification and biomolecules
1. A hybridoma is a hybrid cell produced by fusing an antibody-producing cell (usually a B lymphocyte) with a myeloma cell. This allows the cell to produce monoclonal antibodies indefinitely in culture.
2. To produce monoclonal antibodies, B lymphocytes are isolated from an immunized animal and fused with myeloma cells using polyethylene glycol. The resulting hybridomas are selected in HAT medium, which allows only fused cells to survive and proliferate.
3. Once a hybridoma producing the desired antibody is identified, it can be cultured indefinitely to produce large amounts of monoclonal antibodies, which have applications in research, diagnostics and therapeutics.
Somatic embryogenesis ; 27 march 15. 3.00 pmavinash sharma
This document provides information about indirect somatic embryogenesis in cereal crops. It begins with an introduction to somatic embryogenesis and its importance. It then discusses the types of somatic embryogenesis, including direct and indirect somatic embryogenesis. Indirect somatic embryogenesis is described as occurring through callus formation from explants, from which embryos later develop. The document presents information on indirect somatic embryogenesis systems developed for several cereal crops like rice, wheat, maize and sorghum. It also provides a case study on the indirect somatic embryogenesis of rice variety APMS-6B, including the methods used for callus induction and embryo germination, as well as the results obtained.
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
Walmart Business+ and Spark Good for Nonprofits.pdfTechSoup
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You will hear from Liz Willett, the Head of Nonprofits, and hear about what Walmart is doing to help nonprofits, including Walmart Business and Spark Good. Walmart Business+ is a new offer for nonprofits that offers discounts and also streamlines nonprofits order and expense tracking, saving time and money.
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Walmart Business + (https://business.walmart.com/plus) is a new shopping experience for nonprofits, schools, and local business customers that connects an exclusive online shopping experience to stores. Benefits include free delivery and shipping, a 'Spend Analytics” feature, special discounts, deals and tax-exempt shopping.
Special TechSoup offer for a free 180 days membership, and up to $150 in discounts on eligible orders.
Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
हिंदी वर्णमाला पीपीटी, hindi alphabet PPT presentation, hindi varnamala PPT, Hindi Varnamala pdf, हिंदी स्वर, हिंदी व्यंजन, sikhiye hindi varnmala, dr. mulla adam ali, hindi language and literature, hindi alphabet with drawing, hindi alphabet pdf, hindi varnamala for childrens, hindi language, hindi varnamala practice for kids, https://www.drmullaadamali.com
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This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
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Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
3. INDEX:
1
Introduction
Types of autophagy in plants
History
Autophagy Machinery
Mechanism of autophagy in plants
Functions of autophagy in plants
Future prospects
Conclusion
4. AUTOPHAGY
Autophagy (Greek word) - “Self-eating”
Autophagy : Macromolecule degradation pathway that
recycles damaged or unwanted cell materials upon
encountering stress conditions or during specific
developmental processes
Machinery required for autophagy seems to be conserved from
yeast to plants
2
Tang and Bassham, 2018
5. History:
Christian de Duve - (1963): Coined the term
„Autophagy‟
“Founding father of autophagy research”
Yoshinori Ohsumi - (1992): Identified yeast
AUTOPHAGY-RELATED GENE (ATG),
peroxisome turnover and cytoplasm-to-
vacuole targeting pathway (CVT)
He was awarded the Nobel Prize in
„Physiology or Medicine‟ in 2016
Per Ottar Seglen: Characterize the cup-shaped
structure - phagophore
Frake and Rubinsztein, 2016
3
6. Characterisation of autophagy in yeast:
Demonstrated that autophagy in yeast
is similar to that in mammalian cells
The group used electron microscopy to
identify and characterize double-
membraned „autophagosomes‟ as the
precursors of „autophagic bodies‟ in
yeast
4
8. Continues…,
Ohsumi and colleagues described Atg16p as the third member of
the Atg5p-Atg12p complex
Two years later, a second ubiquitin-like conjugation system was
discovered with Atg8p as the ubiquitin-like protein
6
9. Types of autophagy in plants:
1. Micro-autophagy: Cytoplasmic material congregates the vacuole
surface and becomes trapped by invagination of the tonoplast.
Then tonoplast undergoes scission to release autophagic bodies.
2. Macro-autophagy: Cargo is trapped in cytoplasmic vesicles arised
by expansion of a cup-shaped phagophore that encircles
cytoplasm and ultimately seals to generate the double
membrane-bound autophagosome.
Marshal and vierstra, 20187
10. 3. Mega – autophagy: The tonoplast ruptures to release vacuolar
hydrolases directly into the cytoplasm, where they degrade
cytoplasmic material in situ.
It often represents the final stage of programmed cell death
“The most extreme form of autophagy”
Type of autophagy in animals:
Chaperone-madiated autophagy: Independent of vesicles
Marshal and vierstra, 2018
Continue…,
8
13. Selective autophagy:
“It is an autophagic process that degrades specific
cytoplasmic components such as protein complexes, aggregates,
organelles and pathogens”
Types of selective autophagy:
1. Aggrephagy: Misfolded protien aggregates are degraded by a
specialized autophagic route.
2. Chlorophagy: Quality control mechanism to eliminate
nonfunctional chloroplasts.
3. Mitophagy: Mitophagy is best described in mammals, there is
no clear orthologs in plants.
Marshal and vierstra, 2018
11
14. Continues…,
4. Pexophagy: Under nonstress conditions, pexophagy limits plant
peroxisome abundance.
5. Ribophagy: Biogenesis of ribosomes and subsequent protien
translation are the most energy consuming cellular processes, so
under limited amino acids condition to check translation process
ribophagy will occur.
6. Proteaphagy: Degradation of ubiquitylated protiens via the Ub-
proteasome system.
7. Xenophagy: It helps in enhancement of innate immune response
to protect themselves from pathogen attack.
Marshal and vierstra, 2018
12
15. Regulation of autophagy in plants:
Gene TOR kinase
Yeast - two TOR genes
Plants – only one TOR gene
Antibiotic Rapamycin inhibits
TOR kinase
A key regulator of nutrient
stress induced autophagy.
Two different functional complexs
of TOR:
1. TORC2: Controls spatial cell
growth
2. TORC1: Controls temporal
cell growth, negetively
regulating autophagy. Liu and Bassham, 2012
13
16. Methods for monitoring autophagy:
Immunoblot assays following SDS-PAGE: Here both the
conjugation of ATG12 - ATG5 and the lipidation of ATG8 can
be easily detected based on changes in electrophoretic mobility
Marshal and vierstra, 2018
14
17. Continues…,
• Chemical inhibitors: Blocks the v-ATPases on tonoplast
responsible for vacuolar acidification
Inhibitors enhances the pH of the vacuolar enzymes that
suppresses autophagic body breakdown
Enhances microscopic detection of autophagic bodies and
stabilizes their contents
Marshal and vierstra, 2018
15
19. Continues…,
Fluorescent reporters: Helps in both visual detection of
autophagic structures, and quantitative measures of autophagic
flux
Example: GFP-ATG8 fusions permit detection of autophagosomes
within the cytoplasm and autophagic bodies within the
vacuole by confocal fluorescence microscopy
Marshal and vierstra, 201817
20. Identification and characterization of ATG genes:
ATG genes play key role in autophagy induction
To date, core ATG genes have been identified in 14 crop species
Sequences of ATG genes from Arabidopsis and rice were used as
queries to search against corresponding genomic sequences for
most of 14 crop species
ATG proteins in crops are typically encoded by a single gene
No homologues of ATG3 have been found in grapevine
Autophagy have conserved functions among distinct species but
may also perform species-specific roles Tang and Bassham, 2018
18
24. Leaf senescence:
Leaf senescence is considered to be an important developmental
process because of its critical role in remobilizing nutrients from
mature leaves to support developing organs (Ex: seeds)
The involvement of autophagy in senescence
is supported by upregulation of the ATG
transcripts in older leaves
Higher accumulation of lipidated ATG8 causes higher level of
autophagy activity
Example: Arabidopsis, 15 ATG genes are upregulated during
senescence. Tang and Bassham, 2018
22
25. Seed development:
Increased transcript abundance of many ATG genes can be
observed in the endosperm
Accumulation of ATG8-PE adducts in endosperm will enhance
the seed size
Autophagy helps in the transport of seed storage proteins
Breakdown of starch granules during seed germination is
associated with the autophagy pathway
Example: Wheat, electron microscopy showed that prolamins were
transported from the ER to protein storage vacuoles
(PSVs) through an autophagy-like pathway.
Tang and Bassham, 2018
23
26. Reproductive development:
The first evidence connecting autophagy to reproductive
development was found in wheat
The genes ATG7 and ATG9 will cause autophagy-mediated PCD
in tapetum cells leads to nutrient remobilization during pollen
development
Epidermal cells around the stomium undergoes PCD during
anther dehiscence
Autophagy involved in aborting the florets by causing PCD in
the ovary cells
Example: Tomato, autophagic vesicles were observed in the
epidermal cells surrounding the stomium during their
PCD. Tang and Bassham, 2018
24
27. Vascular development:
A role for autophagy in xylem development was first
demonstrated in poplar
The main conductive cells in xylem are tracheary elements
(TEs), which undergo PCD during differentiation
The small GTP-binding protein RabG3b, co-localized with
ATG8, was shown to be a positive regulator of autophagy and
TE differentiation
The gene METACASPASE9 (MC9) was recently identified as a
negative regulator of autophagy during TE differentiation and is
thought to restrict autophagic cell death to the target cells
Tang and Bassham, 2018
25
28. Objective: To show the role of autophagy in pollen maturation and
reproductive development in rice.
Material & method: Surface sterilized seeds of rice,
TEM analysis of autophagic bodies,
OsATG- mutants,
in vivo imaging of autophagy.
26
29. The Osatg7-1 mutant exhibits a sterility phenotype
27
Cell culture
FM 4-64
GFP-ATG8
E&F: Delayed
anther
development
30. Autophagy is required for male reproductive development in rice
28
95% 45%
Pollen maturity
60% 0.75%
31. Autophagy occurs in tapetal cells during the male reproductive phase
29
Vacuole
enclosed lipid
bodies
No obviouse
autophagasomal
structures in
tetrad stage
Mature cells
tapetum fully
degraded
33. :
Defects in degradation of tapetum layer and lipid bodies
causes abnormal formation of pollen coat and pollen grain,
resulting in sever male sterility.
31
34. Abiotic stress:
1. Nutrient starvation
2. Drought stress
3. Heat stress
Over expression of genes ATG18a and ATG8i conferred to
increased tolerance to nutrient starvation
Increased production of anthocyanin helps in preventing ROS
burst, contributing to higher stress tolerance
Upregulation of ATG5, ATG7 and ATG18a genes induces
autophagy during drought condition
Any mutation in ATG5 or ATG7 led to reduced induction of
autophagy, leading to compromised heat tolerance
Tang and Bassham, 201832
35. Identified regulators of autophagy during drought and heat stress in tomato
Tang and Bassham, 201833
ERF: ethylene response
factor.
AOX: alternative
oxidases.
HsfA1a: heat shock
transcription factor.
DRE: drought
responsive
element
HSE: heat
shock
element
36. Objective: To study the role of autophagy in pepper tolerance to
heat and other abiotic stresses.
Material & method:
Pepper thermotolerent line R9 &
thermosensitive line B6, Heat &
other abiotic stresses treatments.
34
R9 & B6: heat stress – 40 degree
celsius
R9: 4 degree celsius (3 h)
dark for 2d- carbohydrate starvation
200 mM NaCl (3 h) – Salt stress
37. Accumulation of autophagosomes under abiotic stresses
35
LysoTracker Red staining DND-99
E-64 (5-6 leaf stage)
N
S
D
H
C
CS
Normal condition
38. Expression profiles of 29 CaATG genes in response to abiotic stresses.
36
Did not shown significant
response to any condition.
Stress dependent changes
Genes unaffected in some
cases and upregulated in
onother cases
40. Expression profiles of CaATG genes during heat stress in pepper leaf
38
26 genes
upregulated
17 genes
upregulated
41. :
Under abiotic stresses of salt, drought, heat, cold, and
starvation, the accumulation of autophagosome punctates increased
markedly showing the possibility of autophagy participation in the
pepper response to abiotic stresses.
39
42. Plant-pathogen interaction:
Autophagy can serve both a “prosurvival” and a “prodeath” role
upon pathogen infections
Autophagy functions in a prosurvival role during necrotrophic
infection, so it restrict the HR-PCD and prevent runaway cell
death
Autophagy serves a prodeath role upon biotrophic pathogen
infection
Tang and Bassham, 2018
40
43. The dual role of autophagy during plant–pathogen interactions in crops
Tang and Bassham, 201841
Anti-microbial Pro-microbial
44. Objective: To study the role of autophagy genes in wheat immune
responses to fungal pathogens.
Material & method: Plant materials and fungal strain, Virus-
induced gene silencing (VIGS), Evaluation of
powdery mildew resistance.
42
46. 44
Samples: mutants
Continues…,
TaATG6s – regulating autophagy
process enhances Pm21 –
triggered immune response to
powdery mildew.
Pm21
Low level of AB Enhanced level of AB
47. Expression patterns of wheat autophagy-related ATG6 genes
45
TaATG6s are closely
related to the wheat‟s
responses to abiotic stress
factors.
Two leaf stage seedlings
49. Knocking down wheat autophagy-related ATG6 genes weakly compromises the
broad-spectrum resistance gene Pm21-triggered resistance response to Blumeria
graminis f. sp. tritici (Bgt) 47
TaATG6s play a positive
role in Pm21- triggered
wheat resistance response
to Bgt
Trypan blue
50. :
Wheat ATG6s are implicated in immunity to powdery
mildew, playing positive role in the Pm21-triggered resistance
response.
48
51. Symbiotic interaction:
Research with the common bean (Phaseolus vulgaris) indicates
that autophagy may be involved in symbiotic interactions
Trehalose is one of the greatly induced metabolites during the
rhizobium–legume symbiotic interaction
Autophagy related genes ATG3 and PI3K is upregulated in the
root hair
Genes ATG3 and PI3K will silence the trehalase enzyme and
will increase the trehalose sugar content in root hairs
Higher trehalose content leads to increased bacterial viability,
nodule biomass and N assimilation
Tang and Bassham, 2018
49
52. Future perspectives:
New findings such as the involvement of autophagy in
reproductive development are increasing our understanding of
autophagy but much work is still needed
The identification and characterization of new regulatory
mechanisms is a critical area for future research
Some important regulators characterized in Arabidopsis have not
yet been well-studied in crops, for example, TOR and Snf1-
related protein kinase 1 (SnRK1)
The transcriptional control of autophagy should be another
fruitful area for further research.
50
53. Conclusion:
Considering its importance in development and stress responses,
autophagy is a promising target to manipulate for agricultural
benefits like higher yield
Increased expression of ATG genes may be valuable in
agricultural applications, as this can confer a number of benefits
to plants, including enhanced growth, higher yield and increased
stress tolerance
51