This document summarizes a presentation on plant viruses given by Divya Singh at Narendra Deva University of Agriculture and Technology. The presentation covered the introduction of viruses, characteristics of plant viruses, their structure and morphology, composition, and concluded with key points. Plant viruses are obligate intracellular parasites composed of nucleic acid surrounded by a protective protein coat. They can have various shapes, and nucleic acids that are single or double stranded RNA and DNA. The composition of viruses includes proteins, nucleic acids, and sometimes enzymes.
Plant viruses are transmitted from plant to plant in a number of ways.
Transmission of viruses by vegetative propagation.
Mechanical transmission of viruses through sap.
Transmission of viruses by seed.
Transmission of viruses by Pollen.
Transmission of viruses by dodder.
Transmission by vectors.
tobacco mosaic virus in tobacco-significance of TMV, Economic loss of TMV, distribution of TMV, disease cycle of TMV, Favourable condition of TMV, Protein synthesis and RNA replication of TMV,infection process and life cycle of TMV, Disease management of TMV in tobacco plants
CaMV Genome organization & their replication, Cauliflower Mosaic Virus belong to Group VII (ds-DNA-RT), Open circular double stranded DNA of 80kb and CaMV replicates by reverse transcription
Plant viruses are transmitted from plant to plant in a number of ways.
Transmission of viruses by vegetative propagation.
Mechanical transmission of viruses through sap.
Transmission of viruses by seed.
Transmission of viruses by Pollen.
Transmission of viruses by dodder.
Transmission by vectors.
tobacco mosaic virus in tobacco-significance of TMV, Economic loss of TMV, distribution of TMV, disease cycle of TMV, Favourable condition of TMV, Protein synthesis and RNA replication of TMV,infection process and life cycle of TMV, Disease management of TMV in tobacco plants
CaMV Genome organization & their replication, Cauliflower Mosaic Virus belong to Group VII (ds-DNA-RT), Open circular double stranded DNA of 80kb and CaMV replicates by reverse transcription
TOBACCO MOSAIC VIRUS (Genome organization &their replication) TMV is a plant virus which infects a wide range of plants, especially tobacco and other members of the family Solanaceae and cucumbers, and a number of ornamental flowers.
BBTV is the most serious virus disease of bananas and plantains. It occurs in Africa, Asia, Australia, and South Pacific islands. The virus is transmitted in a persistent, circulative, non-propagative manner by the banana aphid, Pentalonia nigronervosa, which has worldwide distribution. The virus is also spread through infected planting material. All banana cultivars are thought to be susceptible, with no known sources of resistance.
The typical symptoms of bunchy top of banana are very distinctive and readily distinguished from those caused by other viruses of banana. Infected plants exhibit a rosetted or ‘bunchy top’ appearance. Once infected, plants do not recover.
Detailed description about viroid, virusoid and prions are described in a simple and detailed manner, will be very to understand about different plant pathogens
INTRODUCTION:
The first plant virus shown to have a DNA genome and the first shown to replicate by reverse transcription.
Worldwide but only causes significantly losses locally.
It is transmitted by aphids .
Type member of the Caulimovirus genus, contains 11 species and 6 possible members.
significantly impact on plant virology and plant molecular biology.
The virus is an important source of gene regulatory elements, used exclusively in the genetic manipulation of plants.
STRUCTURE:Icosachedral with a diameter of 52Â nm built from 420 capsid protein subunits.
It contains a circular double-stranded DNA molecule of about 8.0 kB .
Dna is interrupted by sitespecific discontinuties resulting from its replication by reverse transcription.
After entering the host, the single stranded nicks in the viral DNA are repaired, forming a supercoiled molecule that binds to histones.
DNA is transcriped into a full length .
Replication
Risk Factors:The Cauliflower mosaic virus promoter (CaMV 35S) is used in most transgenic crops to activate foreign genes which have been artificially inserted into the host plant. It is inserted into transgenic plants in a form which is different from that found when it is present in its natural Brassica plant hosts. This enables it to operate in a wide range of host-organism environments which would otherwise not be possible.
TOBACCO MOSAIC VIRUS (Genome organization &their replication) TMV is a plant virus which infects a wide range of plants, especially tobacco and other members of the family Solanaceae and cucumbers, and a number of ornamental flowers.
BBTV is the most serious virus disease of bananas and plantains. It occurs in Africa, Asia, Australia, and South Pacific islands. The virus is transmitted in a persistent, circulative, non-propagative manner by the banana aphid, Pentalonia nigronervosa, which has worldwide distribution. The virus is also spread through infected planting material. All banana cultivars are thought to be susceptible, with no known sources of resistance.
The typical symptoms of bunchy top of banana are very distinctive and readily distinguished from those caused by other viruses of banana. Infected plants exhibit a rosetted or ‘bunchy top’ appearance. Once infected, plants do not recover.
Detailed description about viroid, virusoid and prions are described in a simple and detailed manner, will be very to understand about different plant pathogens
INTRODUCTION:
The first plant virus shown to have a DNA genome and the first shown to replicate by reverse transcription.
Worldwide but only causes significantly losses locally.
It is transmitted by aphids .
Type member of the Caulimovirus genus, contains 11 species and 6 possible members.
significantly impact on plant virology and plant molecular biology.
The virus is an important source of gene regulatory elements, used exclusively in the genetic manipulation of plants.
STRUCTURE:Icosachedral with a diameter of 52Â nm built from 420 capsid protein subunits.
It contains a circular double-stranded DNA molecule of about 8.0 kB .
Dna is interrupted by sitespecific discontinuties resulting from its replication by reverse transcription.
After entering the host, the single stranded nicks in the viral DNA are repaired, forming a supercoiled molecule that binds to histones.
DNA is transcriped into a full length .
Replication
Risk Factors:The Cauliflower mosaic virus promoter (CaMV 35S) is used in most transgenic crops to activate foreign genes which have been artificially inserted into the host plant. It is inserted into transgenic plants in a form which is different from that found when it is present in its natural Brassica plant hosts. This enables it to operate in a wide range of host-organism environments which would otherwise not be possible.
The term ‘virus’ derives from the Latin – poison or Venom.• Viruses are much smaller than bacteria, use their genome (DNA or RNA) to replicate themselves in the host cells and synthesize viral particle.The viral structure mainly having following parts: Viral genome, Capsid, Some are enclosed by an envelope while Some viruses have spikes.• Viruses are classified on basis of their morphology, structure, Genome, presence of envelope, type of host, mode of transmission, replication site and Baltimore classification.
Morphology, Classification, Cultivation and Replication of VirusKrutika Pardeshi
This presentation is Useful for B. Pharmacy SEM III Students to study the Topic Fungi According to PCI Syllabus.
It Consist of Morpholoy of Fungi, Cultivation , Replication and Classification of Virud
Cucumber mosaic virus (CMV) is a plant pathogenic virus. CMV is a linear positive-sense tripartite single-stranded RNA virus. Each genomic segment has a 3' tRNA-like structure and a 5’cap. proteins 1a, 2a, 2b, movement protein-3a (MP) and coat protein-3b sgRNA-4 (CP).
Viruses are small obligate intracellular parasites, which by definition contain either a RNA or DNA genome surrounded by a protective, virus-coded protein coat. Viruses range from the
structurally simple and small parvoviruses and picornaviruses to the large and complex
poxviruses and herpesviruses. Viruses are classified on the basis of morphology, chemical
composition, and mode of replication. The viruses that infect humans are currently grouped into 21 families, reflecting only a small part of the spectrum of the multitude of different viruses whose host ranges extend from vertebrates to protozoa and from plants and fungi to bacteria.
Similar to Structure and composition of plant viruses (20)
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
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.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
2. By
Divya Singh
ID. No. : A5205/10/14
Venue : Seminar Hall
Time: : 11:00 AM
Date : 04/09/2015
DEPARTMENT OF PLANT PATHOLOGY
NARENDRA DEVA UNIVERSITY OF AGRICULTURE AND
TECHNOLOGYKUMARGANJ FAIZABAD 224229
4. Introduction
A virus is a nucleoprotein that multiplies only in the
living host cells and has ability to cause the disease.
Viruses are link between living and non living. They
can reproduce and mutate, have nucleic acid like
living organism. It can be crystallized, and not
reproduce outside the living cell like non living.
Many economically important, destructive diseases
of crops are caused by viruses. e.g. Yellow vein
mosaic of okra , Cauliflower mosaic, Sterility mosaic
of pigeon pea, Bunchy top of banana, Rice tungro
disease, Citrus tristeza disease, Leaf curl of tomato
etc.
5. Involvement of virus in plant disease was proved by M. W.
Beijerinck(1898) who worked on tobacco mosaic disease.
He concluded that pathogenic agent of the disease was a
“Contagium Vivum Fluidum” which he later called VIRUS.
W. M. Stanley(1935) isolated virus in a crystalline protein .
He concluded that the virus was an autocatalytic protein
that could multiply within living cells and got nobel prize in
1946.
F. C. Bawden and N. W. Pirie (1936) proved that TMV was a
nucleoprotein. Nucleic acid in TMV was identified as RNA.
Gierer and Schramm (1956) showed that TMV nucleic acid
free from its protein coat, could alone cause infection.
Black (1963) discovered ds- RNA reoviruses.
B. kassin (1966) discovered satellite virus Tobacco necrosis
satellite virus.
Shepherd et al (1968) discovered first DNA plant virus
causing Cauliflower mosaic disease.
7. Characteristics of plant viruses
Small acellular infectious agent
Obligate intracellular parasite
Made of nucleic acid and protein. Nucleic acid must
be surrounded by a protective protein coat.
Nucleic acid is DNA or RNA (not both) that may be
single stranded or double stranded, linear or circular.
8. Structure of plant viruses
Viruses consist of nucleic acid
either RNA or DNA, surrounded
by a protein coat called the
capsid.
The capsid is composed of small
structural units called
capsomeres.
The capsid protects nucleic acid
from inactivation by the outer
Physical condition.
Rhabdovirus and Tospo virus groups
are provided with an outer membrane
called envelope inside the membrane
the nucleoprotein core is called
nucleocapsid.
Tobacco mosaic virus
capsid
capsomere
Nucleic acid(RNA)
envelope
nucleocapsid
Tomato spotted wilt virus
9. Monopartite genome, Multipartite genome &
Multicomponent viruses
Monopartite genome : The genome of the
viruses is present as single continuous strand. e.g.
Tobacco mosaic virus, Cauliflower mosaic virus
Multipartite genome : Viruses have two or more
molecular species of nucleic acid encapsidated
within same (Tomato spotted wilt virus) or
separate protein cell. Such genome are referred to
as bi-, tri- or multipartite. e.g. Tobacco rattle virus,
Alfalfa mosaic virus.
10. Multicomponent virus :
The division of the genetic information in to two or
more parts is a feature found in certain group of
RNA viruses. In such multicomponent viruses, all
of the nucleic strand component must be present
in the plant to cause infection.
e.g. Brome mosaic virus, Tobacco ring spot virus
11. Genome type and genome structure of some plant
viruses
Virus Genome type Genome structure
Tobacco mosaic virus (rigid rod) ss- RNA Monopartite
Tobacco rattle virus (rigid rod) ss- RNA Bipartite
Potato mop top virus (rigid rod) ss- RNA Tripartite
Potato virus Y (Flexuous rod) ss- RNA Monopartite
Turnip yellow mosaic virus (Isometric) ss- RNA Monopartite
Tobacco ring spot virus (Isometric) ss- RNA Bipartite
Brome mosaic virus (Isometric) ss- RNA Tripartite
Wound tumor virus (Isometric) ds- RNA Monopartite
Lettuce big vein virus (Rigid rod) ds- RNA Tripartite
Tobacco leaf curl virus (Isometric) ss- DNA Bipartite
Banana bunchy top virus (Isometric) ss- DNA Multipartite
Cauliflower mosaic virus (Isometric) ds- DNA Monopartite
12. Shape and Size
Elongated viruses : Some elongated viruses are rigid
rods about 15 by 300 nm e.g. TMV
But most appear as flexous thread, that are usually 10-
13nm wide and 480-2,000 nm long. e.g. Potato virus Y
Rigid rod shaped TMV Flexous thread like potato virus Y
13. Spherical viruses:
Most spherical viruses are polyhedral (isometric) ranging 17-60
nm in diameter. e.g. Turnip yellow mosaic virus (TYNV),
Cauliflower mosaic virus (CaMV).
Tomato spotted wilt virus is surrounded by a membrane and has
a flexible spherical shape about 100nm in diameter.
Spherical particle of CaMV
Twined isometric particles of
Tomato leaf curl virus
14. Bacilliform viruses
These are short bacillus like cylindrical rods that are
about 52-75nm wide and 300-380nm long. e.g.
Rhabdovirus, Rice tungro bacilliform virus (RTBV).
Bacilliform particle of Alfalfa
mosaic virus
RTBV
15. Size and shape of some plant viruses
Virus Particle Shape Size (nm)
Tobacco necrosis satellite virus (Smallest
plant virus)
Isometric 17
Cowpea mosaic virus Isometric 24
Turnip yellow mosaic virus Isometric 28-30
Cauliflower mosaic virus Isometric 50
Alfalfa mosaic virus Bacilliform 28-58 x 18
Wound tumor virus Isometric 60
Tobacco mosaic virus Rigid rod 300 x 18
Potato virus X Flexuous rod 470-580 x 13
Potato virus Y Flexuous rod 680-900 x 11
Citrus tristeza virus (Longest plant virus) Flexuous rod 2000 x 10-12
16. Chemical composition of plant viruses
• Protein (capsid)
• Capsomere
• Nucleic acid
•RNA
•+ve sense RNA
• -ve sense RNA
• ss- RNA
•ds- RNA
DNA
ds- DNA
ss- RNA
17. Composition of viruses
• Protein
Makes up 60-95 % of the virion
• Nucleic acid
Makes up 5-40 % of the virion
Spherical virus- 20-40 %
Elongated virus- 5-6%
• Some viruses contain small amount of
enzyme and membrane lipid.
18. % of Nucleic acid and Protein in some plant viruses
Virus % Nucleic
acid
% Protein Particle shape
Tobacco mosaic virus 5 95 rigid rod
Potato virus X 6 94 flexuous rod
Potato virus Y 5 95 flexuous rod
Beet yellow virus 5 95 flexuous rod
Cauliflower mosaic virus 17 83 spherical
Wound tumor virus 22 78 spherical
Turnip yellow mosaic virus 35 65 spherical
19. Structure and composition of viral nucleic acid
The nucleic acid of most plant viruses consist of RNA,
such as TMV and Potyvirus , but many viruses consist
of DNA for example ; Cauliflower mosaic virus ,
Tobacco and Tomato leaf curl virus.
RNA and DNA may be single – stranded or double
stranded.
e.g. Tobacco mosaic virus (ss-RNA)
Lettuce big vein virus (ds-RNA)
Mung bean yellow mosaic virus (ss-DNA)
Cauliflower mosaic virus (ds-DNA)
Both RNA and DNA are long chain of nucleotides.
20.
21.
22. The size of both RNA and DNA is expressed as the
number of bases i.e. Kilo bases (kb) for the ssRNA and
ssDNA or Kilo base pairs (kbp) for dsRNA and dsDNA.
Virus Genome type No. Of bases
Tobacco mosaic virus ss -RNA 6.4 kb
Bean common mosaic virus ss- RNA 10 kb
Rice tungro spherical viruses ss-RNA 12.4 kb
Cauliflower mosaic virus ds- DNA 8.0 kbp
Tobacco leaf curl virus ss-DNA 2.4-2.8 kb
23. Structure and composition of viral protein
Viral protein consist of amino acids which except
proline; have a general formula R-CH( NH2)-COOH
The amino acids are linked in linear sequence by peptide
bonds between their amino and corboxyl groups.
The linear primary sequence of amino acid is folds in
three dimensions in to structure of maximum stability
in their environment.
The virus coat protein may contain 150 -600 amino
acids and range in molecular weight about 17000-
1,80,000 Dalton. e.g. The protein subunit of TMV consist
of 158 amino acids in a constant sequence and has mass
of 17,600 Dalton.
BCMV – 290 amino acids (M-Wt 28000D)
24.
25. Protein sub units are arranged in helix in rod shaped
viruses. e.g. TMV
In polyhedral viruses the protein subunit are packed
tightly in arrangement that produce 20 faces and
form a shell. e.g. TYMV(Turnip yellow mosaic virus)
TYMV
TMV
26. Viruses like pathogen associated with plant disease
Viroids : Small (250 – 400 nucleotide ), naked, single-
stranded, circular RNAs capable of causing disease in
plant by themselves. e.g. Potato spindle tuber viroid, Citrus
exocortis viroid
Satellite viruses : Virus associated with certain typical
viruses (helper virus) and depend on the later for
multiplication and plant infection. e.g. Tobacco necrosis
satellite virus
Satellite RNAs : Small, linear RNAs found in virions of
certain multicomponent viruses may increase or decrease
the severity of viral infection. e.g. satellite RNA (CMV-
RNA5) associated with Cucumber mosaic virus
27. Conclusion
Virus is chemically a nucleoprotein that multiplies
only in the living cells and has ability to cause disease.
Nucleic acid may be RNA or DNA that is surrounded
by a protective protein coat called capsid.
Plant viruses may be elongated, spherical and
bacilliform in shape.
The nucleic acids RNA and DNA may be single
stranded or double stranded.
Nucleic acid % is lower in elongated viruses where as
spherical viruses contain higher % of nucleic acid.
