Transgenic plants are crop plants that contain genes artificially inserted from unrelated species. This allows plant breeders to generate more productive varieties with new trait combinations beyond traditional breeding. The process involves identifying, isolating, and cloning a novel gene, transforming the target plant, selecting transgenic tissues, and regenerating the plant. Common transgenic crops provide herbicide resistance, insect resistance using Bt genes, virus resistance, altered oil content, delayed fruit ripening, and drought tolerance. These traits aim to improve crop yields, qualities, and resist biotic and abiotic stresses.
HYBRIDIZATION & HAPLOID PRODUCTION
Introduction
WIDE HYBRIDIZATION
INTER-SPECIFIC HYBRIDIZATION
Barriers to distant hybridization
Techniques to overcome barriers
Haploids and Doubled Haploids in Plant
Production of haploids and doubled haploids
a) Induction of maternal haploids
Wide hybridization
3. In vitro induction of maternal haploids – gynogenesis
Induction of paternal haploids – Androgenesis
Production of Homozygous Diploid Plants
Application of Haploids in Plant Breeding
Importance and Implications of Anther and Pollen Culture
An overview of the Agrobacterium-mediated gene transfer process. Moreover, studied different kinds of Agrobacterium species are involved in this mechanism.
Agrobacterium is a rod-shaped, Gram-negative bacteria found mostly in the soil. It is a plant pathogen that is responsible for causing crown gall disease in them. This bacteria is also known as the natural genetic engineer because of it's the ability to integrate its plasmid Gene into the plant genome.
Agrobacterium tumefaciens transfer of their genetic material T-DNA of Ti-plasmid into the plant cell: A: Agrobacterium tumefaciens; B: Agrobacterium genome; C: Ti Plasmid : a: T-DNA , b: Vir genes , c: Replication origin , d: Opines catabolism genes; D: Plant cell
A Ti-Plasmid (tumor-inducing plasmid) is a ds, circular DNA that often, but not always. It's a piece of genetic equipment that transfers genetic material from bacterial cells means Agrobacterium tumefaciens into plant cells used to induce tumors in the plant. The Ti-plasmid is damage when Agrobacterium is grown above 28 °C. Such cured bacteria don't induce crown gall disease in the plant due to they are avirulent. The Ti-Plasmid are classified into two types on the basis of opine genes are present in T-DNA.
The Plasmid has 196 genes that code for 195 proteins. There is no one structural RNA. The plasmid is 206.479 nucleotides long. the GC content is 56% and 81% of the genetic material is coding genes.
The modification of this plasmid is a very important source in the production of transgenic plants.
The T-DNA must be cut out of the circular plasmid. A VirD1/D2 complex nicks the DNA at the left and right border sequences. The VirD2 protein is covalently attached to the 5' end. VirD2 contains a motif that leads to the nucleoprotein complex being targeted to the type IV secretion system (T4SS).
In the cytoplasm of the recipient cell, the T-DNA complex becomes coated with VirE2 proteins, which are exported through the T4SS independently from the T-DNA complex. Nuclear localization signals, or NLS, located on the VirE2 and VirD2 are recognized by the importin alpha protein, which then associates with importin beta and the nuclear pore complex to transfer the T-DNA into the nucleus. So that the T-DNA can integrate into the host genome.
We inoculate Agrobacterium containing our genes of interest, onto wounded plant tissue explants. The Agrobacterium then transfers the gene of interest into the DNA of the plant tissue.
A process where an embryo is derived from a single somatic cell or group of somatic cells. Somatic embryos (SEs) are formed from plant cells that are not normally involved in embryo formation.
Embryos formed by somatic embryogenesis are called Embryoids.
The process was discovered for the first time in Daucas carota L. (carrot) by Steward (1958), Reinert (1959).
Presented by- MD JAKIR HOSSAIN
Doctoral Research Scholar
Department of Agricultural Genetic Engineering ,
Faculty of Agricultural Sciences and Technologies,
Nigde Omer Halisdemir University, Turkey
E. Mail- mjakirbotru@gmail.com
The different types of external stresses that influence the plant growth and development.
These stresses are grouped based on their characters
Biotic
Abiotic
Almost all the stresses, either directly or indirectly, lead to the production of reactive oxygen species (ROS) that create oxidative stress in plants.
This damages the cellular constituents of plants which are associated with a reduction in plant yield.
1.What is plant tissue culture?
2.Production of virus free plants.
3.History.
4.Virus elimination by heat treatment.
5.Virus elimination by Meristem Tip culture.
6.Factor affecting virus eradication by Meristem Tip culture.
7.Chemotherapy.
8.Virus elimination through in vitro shoot-tip Grafting.
9.Virus Indexing.
10.Conclusion .
11.References .
HYBRIDIZATION & HAPLOID PRODUCTION
Introduction
WIDE HYBRIDIZATION
INTER-SPECIFIC HYBRIDIZATION
Barriers to distant hybridization
Techniques to overcome barriers
Haploids and Doubled Haploids in Plant
Production of haploids and doubled haploids
a) Induction of maternal haploids
Wide hybridization
3. In vitro induction of maternal haploids – gynogenesis
Induction of paternal haploids – Androgenesis
Production of Homozygous Diploid Plants
Application of Haploids in Plant Breeding
Importance and Implications of Anther and Pollen Culture
An overview of the Agrobacterium-mediated gene transfer process. Moreover, studied different kinds of Agrobacterium species are involved in this mechanism.
Agrobacterium is a rod-shaped, Gram-negative bacteria found mostly in the soil. It is a plant pathogen that is responsible for causing crown gall disease in them. This bacteria is also known as the natural genetic engineer because of it's the ability to integrate its plasmid Gene into the plant genome.
Agrobacterium tumefaciens transfer of their genetic material T-DNA of Ti-plasmid into the plant cell: A: Agrobacterium tumefaciens; B: Agrobacterium genome; C: Ti Plasmid : a: T-DNA , b: Vir genes , c: Replication origin , d: Opines catabolism genes; D: Plant cell
A Ti-Plasmid (tumor-inducing plasmid) is a ds, circular DNA that often, but not always. It's a piece of genetic equipment that transfers genetic material from bacterial cells means Agrobacterium tumefaciens into plant cells used to induce tumors in the plant. The Ti-plasmid is damage when Agrobacterium is grown above 28 °C. Such cured bacteria don't induce crown gall disease in the plant due to they are avirulent. The Ti-Plasmid are classified into two types on the basis of opine genes are present in T-DNA.
The Plasmid has 196 genes that code for 195 proteins. There is no one structural RNA. The plasmid is 206.479 nucleotides long. the GC content is 56% and 81% of the genetic material is coding genes.
The modification of this plasmid is a very important source in the production of transgenic plants.
The T-DNA must be cut out of the circular plasmid. A VirD1/D2 complex nicks the DNA at the left and right border sequences. The VirD2 protein is covalently attached to the 5' end. VirD2 contains a motif that leads to the nucleoprotein complex being targeted to the type IV secretion system (T4SS).
In the cytoplasm of the recipient cell, the T-DNA complex becomes coated with VirE2 proteins, which are exported through the T4SS independently from the T-DNA complex. Nuclear localization signals, or NLS, located on the VirE2 and VirD2 are recognized by the importin alpha protein, which then associates with importin beta and the nuclear pore complex to transfer the T-DNA into the nucleus. So that the T-DNA can integrate into the host genome.
We inoculate Agrobacterium containing our genes of interest, onto wounded plant tissue explants. The Agrobacterium then transfers the gene of interest into the DNA of the plant tissue.
A process where an embryo is derived from a single somatic cell or group of somatic cells. Somatic embryos (SEs) are formed from plant cells that are not normally involved in embryo formation.
Embryos formed by somatic embryogenesis are called Embryoids.
The process was discovered for the first time in Daucas carota L. (carrot) by Steward (1958), Reinert (1959).
Presented by- MD JAKIR HOSSAIN
Doctoral Research Scholar
Department of Agricultural Genetic Engineering ,
Faculty of Agricultural Sciences and Technologies,
Nigde Omer Halisdemir University, Turkey
E. Mail- mjakirbotru@gmail.com
The different types of external stresses that influence the plant growth and development.
These stresses are grouped based on their characters
Biotic
Abiotic
Almost all the stresses, either directly or indirectly, lead to the production of reactive oxygen species (ROS) that create oxidative stress in plants.
This damages the cellular constituents of plants which are associated with a reduction in plant yield.
1.What is plant tissue culture?
2.Production of virus free plants.
3.History.
4.Virus elimination by heat treatment.
5.Virus elimination by Meristem Tip culture.
6.Factor affecting virus eradication by Meristem Tip culture.
7.Chemotherapy.
8.Virus elimination through in vitro shoot-tip Grafting.
9.Virus Indexing.
10.Conclusion .
11.References .
Somaclonal Variation in Plant tissue culture - Variation in somaclones (somatic cells of plants)
Somaclonal variation # Basis of somaclonal variation # General feature of Somaclonal variations # Types and causes of somaclonal variation # Isolation procedure of somaclones via without in-vitro method and with in-vitro method with their limitations and advantages # Detection of isolated somaclonal variation # Application (with examples respectively related to crop improvement) # Advantages and disadvantages of somaclonal variations.
https://www.youtube.com/watch?v=IZwrkgADM3I
Also watch, Gametoclonal variation slides to understand, how to changes occur in gametoclones of plants.
https://www.slideshare.net/SharmasClasses/gametoclonal-variation
Haploid Production - Techniques, Application & Problem ANUGYA JAISWAL
Haploid is applied to any plant originating from a sporophyte (2n) and containing (n) number of chromosomes.
Artificial production of haploids was attempted through distant hybridization, delayed pollination, application of irradiated pollen, hormone treatment and temperature shock.
The artificial production of haploids until 1964 was attempted through:
1. Distant hybridization
2. Delayed pollination
3. Application of irradiated pollen
4. Hormone treatments
5. Temperature shocks
The development of numerous pollen plantlets in anther cultures of Datura innoxia, first reported by two Indian scientists (Guha and Maheshwari, 1964, 1966), was a major breakthrough in haploid breeding of higher plants.
The technique of haploid production through anther culture ('anther - androgenesis') has been extended successfully to numerous plant species, including many economically important plants, such as cereals and vegetable, oil and tree crops.
In the following slides, I have discussed the need for developing insect-resistant transgenic plants, the sources of transgenes, and methods for development
A transgenic crop plant contains a gene or genes which have been artificially inserted, instead of the plant acquiring them through pollination. The inserted gene sequence (known as the transgene) may come from another unrelated plant, or from a completely different species: for example, transgenic Bt corn, which produces its own insecticide, contains a gene from a bacterium. Plants containing transgenes are often called genetically modified or GM crops.
What is the need of transgenic plants?
A plant breeder tries to assemble a combination of genes in a crop plant which will make it as useful and productive as possible. The desirable genes may provide features such as higher yield or improved quality, pest or disease resistance, or tolerance to heat, cold and drought. This powerful tool enables plant breeders to do what they have always done - generate more useful and productive crop varieties containing new combinations of genes - but this approach expands the possibilities beyond the limitations imposed by traditional cross pollination and selection techniques.
Somaclonal Variation in Plant tissue culture - Variation in somaclones (somatic cells of plants)
Somaclonal variation # Basis of somaclonal variation # General feature of Somaclonal variations # Types and causes of somaclonal variation # Isolation procedure of somaclones via without in-vitro method and with in-vitro method with their limitations and advantages # Detection of isolated somaclonal variation # Application (with examples respectively related to crop improvement) # Advantages and disadvantages of somaclonal variations.
https://www.youtube.com/watch?v=IZwrkgADM3I
Also watch, Gametoclonal variation slides to understand, how to changes occur in gametoclones of plants.
https://www.slideshare.net/SharmasClasses/gametoclonal-variation
Haploid Production - Techniques, Application & Problem ANUGYA JAISWAL
Haploid is applied to any plant originating from a sporophyte (2n) and containing (n) number of chromosomes.
Artificial production of haploids was attempted through distant hybridization, delayed pollination, application of irradiated pollen, hormone treatment and temperature shock.
The artificial production of haploids until 1964 was attempted through:
1. Distant hybridization
2. Delayed pollination
3. Application of irradiated pollen
4. Hormone treatments
5. Temperature shocks
The development of numerous pollen plantlets in anther cultures of Datura innoxia, first reported by two Indian scientists (Guha and Maheshwari, 1964, 1966), was a major breakthrough in haploid breeding of higher plants.
The technique of haploid production through anther culture ('anther - androgenesis') has been extended successfully to numerous plant species, including many economically important plants, such as cereals and vegetable, oil and tree crops.
In the following slides, I have discussed the need for developing insect-resistant transgenic plants, the sources of transgenes, and methods for development
A transgenic crop plant contains a gene or genes which have been artificially inserted, instead of the plant acquiring them through pollination. The inserted gene sequence (known as the transgene) may come from another unrelated plant, or from a completely different species: for example, transgenic Bt corn, which produces its own insecticide, contains a gene from a bacterium. Plants containing transgenes are often called genetically modified or GM crops.
What is the need of transgenic plants?
A plant breeder tries to assemble a combination of genes in a crop plant which will make it as useful and productive as possible. The desirable genes may provide features such as higher yield or improved quality, pest or disease resistance, or tolerance to heat, cold and drought. This powerful tool enables plant breeders to do what they have always done - generate more useful and productive crop varieties containing new combinations of genes - but this approach expands the possibilities beyond the limitations imposed by traditional cross pollination and selection techniques.
Genetically modified organisms (GMOs) are organisms in which the
genetic material has been altered using recombinant DNA technology.
Genetic manipulation involves a wide variety of modifications to produce
nutritionally valued GM crops. In some cases, genetic modifications
represent more faster and efficient mechanisms for achieving desired
resulting traits. This review indicate the mechanism of group of actions
with various biotechnological tool utilize to carry out genetic
modification, their benefits, etc. Production of GM food crops provides
new ways to fulfill future food requirments but risk associated factors
cannot be neglected. To overcome these problems and to cope with the
continuous increase in the number and variety of GMOs, new approaches
are needed. India has approved cultivation of some GM crops but due to
lack of proper knowledge and religious factors lead to stunted outcomes
ignoring environment cleanliness and hunger of malnourished segments.
So more attention still needed for its adoption globally by ensure its
safety for human utilization.
Genetic Engineering in Insect Pest management Mohd Irshad
gene incorporation is gaining attention across the globe with the aim of improving plant health, crop protection, and sustainable crop production. This versatile method of Scientific cultivation should be adopted by the growers as it has been investigated and assessed by experts and environmentalists. There is not any kind of toxic effect on mammalian.
Highly descriptive and illustrative presentation based on Biotechnology chapter 12 of NCERT class XII.
This is an important topic especially from biological research point of view.
This is to help students thoroughly understand the topic for exams as well as for future practical applications.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
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.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
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.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
1. Submitted to:
Dr. K. P. Pachchigar
Submitted by:
Gami Pankajkumar B.
M.Sc.(Agri.)GPB 1st sem.
MBB501: Principles of Biotechnology
2. What Are Transgenic Plants?
• A transgenic crop plant contains a gene or genes which
have been artificially inserted instead of the plant
acquiring them through pollination.
• The inserted gene sequence (known as the transgene)
may come from another unrelated plant, or from a
completely different species: for example transgenic Bt
corn, which produces its own insecticide, contains a gene
from a bacterium.
• Plants containing transgenes are often called genetically
modified or GM crops, although in reality all crops have
been genetically modified from their original wild state
by domestication, selection and controlled breeding over
long periods of time.
3. What is the need of transgenic plants?
• A plant breeder tries to assemble a combination of genes
in a crop plant which will make it as useful and
productive as possible.
• The desirable genes may provide features such as higher
yield or improved quality, pest or disease resistance, or
tolerance to heat, cold and drought.
• This powerful tool enables plant breeders to do what
they have always done - generate more useful and
productive crop varieties containing new combinations
of genes - but this approach expands the possibilities
beyond the limitations imposed by traditional cross-
pollination and selection techniques.
4. Procedure in production of Transgenic crops
The novel transgene is identified ,isolated and
clonned
Designing of gene
The target plants are transformed
(by vector mediated or direct method)
Selection of transgenic plant tissue/ cells
Regeneration of the transgenic plant by the
process of plant tissue culture
5. TRANSFORMATION
Gene transfer or uptake of DNA refers to the process
that moves a specific piece of DNA into cell.
The directed desirable gene transfer from one organism
to another and the subsequent stable integration &
expression of foreign gene into the genome is referred
as genetic transformation.
6. TRANSFORMATION METHODS:
Chemical
• Lypofection
• Protoplast based
• Polyamine based
• Silicon carbide
• Pollen based
Physical
• Gene gun
• Electrophoration
• Microinjection
• Macroinjection
Biological
• Agrobacterium
• Agroinfection
7. Applications:
Crop Improvement
The following traits are potentially useful to plant genetic
engineering for abiotic and biotic stress resistance.
Genetically Engineered Traits: The Big Six.
1. Herbicide Resistance
2.Insect Resistance
3. Virus Resistance
4. Altered Oil Content
5. Delayed Fruit Ripening
6. Drought tolerence
8. 1. Herbicide Resistance
Over 63% of transgenic crops grown globally have
herbicide resistance traits. Herbicide resistance is achieved
through the introduction of a gene from a bacterium
conveying resistance to some herbicides.
• In modern agriculture, the herbicides have been taken the
major role in weed control. Though the uses of herbicide
offers several advantages, i.e., permitting economic weed
control, increasing the efficiency of crop production
resulting in higher crop yield and biodegradability etc., they
are endowed with several limitations as well, i.e., lack of
selectivity is one of the most important limitation.
9. Genetic engineering offers the scope of modifying
plants through integration of genes providing resistance
to broad spectrum herbicides.
Three approaches have been followed in the
production of herbicide resistant plants:
i) over production of herbicide sensitive biochemical
compounds;
ii) structural alteration of a biochemical target
compound resulting in reduced herbicide affinity, and
iii) detoxification or degradation of the herbicide
before it reaches the biochemical target inside the
plant cell.
10. A) Glyphosate Resistance
One of the most famous kinds of GM crops are
"Roundup Ready", or glyphosate-resistant. Glyphosate,
(the active ingredient in Roundup) kills plants by
interfering with the shikimate pathway in plants, which is
essential for the synthesis of the aromatic amino acids
like a phenylalanine, tyrosine and tryptophan.
More specifically, glyphosate inhibits the enzyme 5-
enolpyruvylshikimate-3-phosphate synthase (EPSPS).
The gene encoding EPSPS has been transferred from
glyphosate-resistant E. coli into plants, which allow
plants to be resistant.
11. Also some micro-organisms have a version of EPSPS
that is resistant to glyphosate inhibition. One of these
was isolated from an Agrobacterium strain CP4 (CP4
EPSPS) that was resistant to glyphosate.
It produce an enzyme that inactivates glyphosate.
Glyphosate is rapidly metabolized by Glyphosate
oxidoreductase (GOX)
14. b) Glufosinate Resistance
Glufosinate (the active ingredient in phosphinothricin)
mimics the structure of the amino acid glutamine, which
blocks the enzyme glutamate synthase.
Plants receive a gene from the bacterium Streptomyces
that produce a protein that inactivates the herbicide.
c) Bromoxynil Resistance
A gene encoding the enzyme bromoxynil nitrilase
(BXN) is transferred from Klebsiella pneumoniae
bacteria to plants.
Nitrilase inactivates the Bromoxynil before it kills the
plant.
d) Sulfonylurea.
Kills plants by blocking an enzyme needed for synthesis
of the amino acids valine, leucine, and isoleucine.
Resistance generated by mutating a gene in tobacco
plants, and transferring the mutated gene into crop
plants.
15. 2. Insect Resistance
Progress in engineering insect resistance in transgenic
plants has been achieved through the use of insect
control protein genes of Bacillus thuringiensis.
Insect resistance was first reported in tobacco (Vaeck et
al., 1987) and tomato (Fischhoff et al., 1987). Today
insect resistant transgenes, whether of plant, bacterial or
other origin, can be introduced in to plants to increase
the level of insect resistance.
More than 400 genes encoding toxins from wide range
of B. thuringiensis have been identified so far and
approximately 40 different genes conferring insect
resistance have been incorporated into crops.
16. Genes conferring insect resistance to plants have
been obtained from microorganisms: Bt gene from
Bacillus thuringiensis; ipt gene (isopentyl transferase)
from Agrobacterium tumefaciens, cholesterol oxidase
gene from a streptomyces fungus and Pht gene from
Photorhabdus luminescens.
Bt toxin gene:
Bacillus thuringiensis (Bt) is an entomocidal
bacterium that produces an insect control protein.
Bt genes code for the Bt toxin.
Most Bt toxins are active against Lepidopteran larvae
but some are specific for Dipteran and Coleopteran
insects. The insect toxicity of Bt resides in a large
protein.
17. The toxins accumulate as crystal proteins (CS-
endotoxins) inside the bacteria during sporulation. They
are converted to active form upon infection by
susceptible insect, thereby killing the insect by
disruption of ion transport across the brush borders/
membranes of susceptible insect.
Based on their host range Hofte and Whiteley classified
Bt toxins into 14 distinct groups and 4 classes (Hofte
and Whiteley 1989) viz.
- CryI (active against Lepidoptera)
- CryII (Lepidoptera and Diptera)
-CryIII (Coleoptera) and
- CryIV (Diptera).
18. Cry proteins are toxic to insects (mainly against
lepidopteran, coleopteran, dipteran, and nematodes), but
non-toxic to human and animals (BANR, 2000).
19. Toxic Action of Cry Proteins
When Cry protein ingested by lepidopteran insect larvae ,
a protoxin is solubilized by the high pH of the gut lumen
and solubilization of the protoxin is activated through
cleavage by digestive enzymes into a smaller (~60kDa)
fragment (Hofte and Whiteley, 1989; OECD, 2007).
Then, activated toxic fragment can binds to receptors on
the membrane of the insect’s midgut epithelial cells (Bravo
et al., 1992) and follows the activation of an apoptotic signal
cascade pathway (Zhang et al., 2006), causing formation of
pores . This leads to osmotic shock, cell lysis and insect
death (Lorence et al., 1995).
20. • Mode of action of Cry toxin
Mode of action of Bacillus thuringiensis in lepidopteran caterpillar: 1. ingestion
by bacteria; 2. solubilization of the crystals; 3. activation protein; 4. binding of
proteins to the receptors 5. membrane pore formation and cell disruption
(Modified from: Schünemann et al., 2014).
21. Credit:Transgenic plants: resistance to abiotic and biotic stresses :Akila Wijerathna-
Yapa ;Journal of Agriculture and Environment for International Development -
JAEID 2017, 111 (1): 245-275DOI: 10.12895/jaeid.20171.643
22. 3. Virus Resistance
Chemicals are used to control the insect vectors of
viruses, but controlling the disease itself is difficult
because the disease spreads quickly.
Plants may be engineered with genes for resistance to
viruses, bacteria, and fungi.
Virus diseases of cultivated plants cause substantial loss
in food, forage and fiber crops throughout the world. No
large scale methods exist for curing plants once they
have become virus infected.
The development of molecular strategies for the control
of virus diseases has been especially successful owing
to small genomic size of plant viruses which make them
particularly amenable to molecular techniques for
cloning.
23. The approach is to identify those viral genes or gene
products which was present at an improper time or in wrong
amount ,will interfere with the normal functions of infection
process and prevent disease development.
Virus Coat Protein Mediated Cross Protection
The concept of cross protection is the ability of one virus to
prevent or inhibit the effect of a second challenge virus.
Transgenic tobacco expressing tobacco mosaic virus
(TMV) coat protein which resistance similar to that occurs in
viral mediated cross protection (Powell-Abel et al., 1986).
The resistance reduce numbers of infection sites on
inoculated leaves, suggesting that an initial step in the virus
life cycle has been disrupted.
It has been demonstrated that TMV cross protection may
result from the coat protein of the protecting virus preventing
un-coating of the challenge virus RNA.
24. This approach has been used in several crops
like tobacco, tomato, potato, rice, maize, melons,
alfalfa, sugar beet etc.
Courtesy:Transgenic plants: resistance to abiotic and biotic stresses :Akila
Wijerathna-Yapa ;Journal of Agriculture and Environment for International
Development - JAEID 2017, 111 (1): 245-275DOI:
10.12895/jaeid.20171.643
25. 4. Altered Oil Content
• Oil quality can be changed by genetic modification of crops
or by chemical modification of the fatty acids.
Conventional breeding has been remarkably successful in
modifying oil quality.
• Genetic engineering now offers unique opportunities to
produce novel fatty acids. The various strategies used for
modifying fatty acids are as follows:
• (i) introduction of a novel enzyme, e.g., an acyl transferase
or an acyl-ACP thioesterase, acyl-ACP desaturase, etc.,
• (ii) suppression of an enzyme activity, e.g., α acyl-ACP
desaturase),
• (iii) site-directed mutagenesis to alter the specificity, etc. of
an enzyme, e.g., acyl-ACP desaturase, etc., and
• (iv) creation of hybrid genes to generate novel enzyme
activities.
26. Perhaps the most successful example is the increased
lauric acid content of B. napus; a transgenic line name
'Laurical' has been released for commercial cultivation.
Lauric acid does not occur naturally in Brassica sp. oil. But
seeds of undomesticated California bay ( Ullibellularia
californica) accumulate laurate (12:0).
The gene encoding lauroyl-ACP thioesterase was isolated
from U. californica and transferred into B. napus. Some of
the transgenic lines showed upto 60% lauric acid in their
oils. Thereis some evidence that a part of the lauric acid in
transgenic B. napus is subjected to ß-oxidation.
Varieties of canola and soybean plants have been
genetically engineered to produce oils with better cooking
and nutritional properties.
Genetically engineered plants may also be able to produce
oils that are used in detergents, soaps, cosmetics, lubricants,
and paints.
27. 5. Delayed Fruit Ripening
Allow for crops, such as tomatoes, to have a higher
shelf life.
Tomatoes generally ripen and become soft during
shipment to a store.
Tomatoes are usually picked and sprayed with the
plant hormone ethylene to induce ripening, although
this does not improve taste.
Tomatoes have been engineered to produce less
ethylene so they can develop more taste before
ripening, and shipment to markets.
28. • Transgenic tomato with delayed ripening:lower level of
ethylene production
• Reduced activity of the cell wall degrading enzymes, e.g.
polygalacturonases
29. –Produced by calgene by blocking the
polygalacturonase (PG) gene, which is involved
in spoilage. PG is an enzyme that breaks down
pectin, which is found in plant cell walls.
–Plants were transformed with the anti-sense PG
gene, which is mRNA that base pair with mRNA
which plant produces, essentially blocking the
gene from translation.
–First genetically modified organism to be
approved by the FDA, in 1994.
31. Use of gene for 1-aminocyclopropane-1-
carboxylic acid(ACC) deaminase:
s-adenosyl methionine (SAM)
1-aminocyclopropane-1-carboxylic acid(ACC)
ethyleneOther
metabolites
SAM hydrolase
(bacteriophage T3)
32. 6.Drought resistance:
A number of such genes have been identified, isolated,
cloned and expressed in plants, which are potential
sources of resistance to abiotic stresses.
These genes include Rab (responsive to abscisic acid)
and SalT (induced in response to salt stress) genes of rice;
genes for enzymes involved in proline biosynthesis in
bacteria (proBA and proC in E. coli) and plants.
In plants, proline is preferentially produced from
ornithine under normal conditions. However, under stress
it is made directly from glutamate, the first two reactions
of the pathway being catalyzed by a single enzyme ∆1-
pyrroline-5-carboxylate synthetase (P5CS) .
33. The gene encoding P5CS (as well as that encoding P5CR,
A1-pyrroline-5-carboxylate reductase; a non-rate limiting
enzy me of the pathway) has been isolated from soybean
and mothbean, and cloned.
The mothbean PSCS gene has been transferred and
overexpressed in tobacco. The transgenic plants produced
10- to 15-fold more proline than the control plants.
The leaves of transgenic plants retained a higher osmotic
potential and showed a greater root biomass under water
stress than did the control plants. Thesefindings indicates
that overexpression of P5CS in plants enhances their
tolerance to osmotic stress.
34. Genetically Engineered Foods
1. More than 60% of processed foods in the United States
contain ingredients from genetically engineered
organisms.
2. 12 different genetically engineered plants have been
approved in the United States, with many variations of
each plant, some approved and some not.
3. Soybeans.
Soybean has been modified to be resistant to broad-
spectrum herbicides.
Scientists in 2003 removed an antigen from soybean
called P34 that can cause a severe allergic response.
35. 4. Corn
Bt insect resistance is the most common use of
engineered corn, but herbicide resistance is also a
desired trait.
Products include corn oil, corn syrup, corn flour,
baking powder, and alcohol.
By 2002 about 32% of field corn in the United
States was engineered.
5. Canola.
More than 60% of the crop in 2002 was genetically
engineered; it is found in many processed foods,
and is also a common cooking oil.
36. 6. Cotton.
More than 71% of the cotton crop in 2002 was
engineered.
Engineered cottonseed oil is found in pastries,
snack foods, fried foods, and peanut butter.
7.Nutritionally Enhanced Plants—Golden Rice:
More than one third of the world’s population relies
on rice as a food staple, so rice is an attractive target
for enhancement.
Golden Rice was genetically engineered to produce
high levels of beta-carotene, which is a precursor to
vitamin A. Vitamin A is needed for proper eyesight.
–
37. Golden Rice was developed by Ingo Potrykus and
Peter Beyer, and several agencies are attempting to
distribute the rice worldwide
Other enhanced crops include iron-enriched rice
and tomatoes with three times the normal amount
of beta-carotene
Rice endosperm synthesize geranyl-geranyl
pyrophosphate which can be converted into ß-
carotene by 3 enzymes.
Phytoene desaturase and Lycopene ß Cyclase
derived from daffodil(Narcissus pseudonarcissus)
and Carotene desaturase from Erwinia uredova.
38. The transgenes providing these enzyme activities were
transferred into rice through Agrobacterium mediated
transformation.
The resulting rice looks yellowish orange in colour
and contain ß-carotene kwnon as ‘Golden Rice’.
40. Advantages of Transgenic crops:
• Resistance to biotic
stress(insects,diseases,viruses)
• Resistance to abiotic stress
• Herbicide resistance
• Improved quality
• Male sterile crops
• High yield
• Cheap to maintain disease resistant
species
• High adaptability
41. Disadvantages
• Allergic reactions
• Reducing the numbers of pest insects in
farmland and impacting biodiversity.
• Significant negative impact on
wildlife(wider effects on food chains )
• Chance of developing resistance in weeds
(uncontrollable weeds)