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Plant Promoters
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Promoters:
A site in a DNA molecule at which RNA polymerase and
transcription factors bind to initiate transcription of specific
genes to mRNA
The promoter acts as the regulator for the level of gene
expression.
Promoters are located near the genes they regulate, on the
same strand and typically upstream (towards the 5' region of
the sense strand).
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Cis-acting elements - DNA sequences in the
vicinity of the structural portion of a gene that
are required for gene expression
Trans-acting factors - factors, usually
considered to be proteins, that bind to the cis-
acting sequences to control gene expression
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Eukaryotic Promoters
CAP site TAC
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Core promoters:
Core promoters are Minimal promoters thatcontain TATA box.
The TATA box is also called Goldberg-Hogness box.
These DNA sequences are (cis-elements) foundin archaea and eukaryotes
TATA box is essential for RNA polymerase II-dependent transcription
Located at about -20 t0 -35 bp upstream fromtranscription start site.
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Types of Promoters
Constitutive promoters:
Inducible promoters:
Tissue-specific promoters :
Synthetic promoters:
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Constitutive promoters
They facilitate expression of the gene in all tissues
regardless of the surrounding environment and
development stage of the organism
They are active in all circumstances in the cell.
Examples:Plant pathogen/Dicot promoters
Opine promoters
CaMV 35S promoterMonocot promoters
Plant ubiquitin promoter (Ubi)
Rice actin 1 promoter (Act-1)
Maize alcohol dehydrogenase 1 promoter (Adh-1)
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Inducible promoters
which are only expressed under the presence offactors /compounds.
They may be Chemically or Physically induced
Types & Example:Chemically induced
1. Alcohol-regulated:
2. Tetracycline-regulated:
3. Steroid-regulated:
4. Metal-regulated:
5. Pathogenesis-relatedPhysically induced
1. Temperature-regulated promoters
2. Light-regulated promoters
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Tissue Specific Promoters
which operate in particular tissues and at certaindevelopmental stages of a plant.
They may be induced by endogenous and exogenous
factors.
Root Promoters ,Fruit Promoters ,Seed Promoters etc.
Example:
Phosphoenolpyruvate (PEP) carboxylase promoter
which induces gene expression only in cells that are
actively involved in photosynthesis
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Synthetic Promoters:
Promoters made by bringing together the
primary elements of a promoter region from
diverse origins.
Chimeric genes form through thecombination of portions of one or more coding
sequences to produce new genes
By fusing the promoters of two different genes
into one chimeric gene.
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1.Promoters and UAS from opine synthase genes:
Patents granted in the U.S. and Australia directed to promotersand Upstream Activating Sequences (UAS) derived from
opine synthase genes, specially from the ocs and mas genes of
A. tumefaciens;
2. 35S-enhanced maspromoter:
Patents granted in the U.S. and Canada directed to a mas
promoter enhanced by a UAS from CaMV 35S gene
Mannopine synthase (mas)
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CaMV 35S Promoter
1. Caulifl ower mosaic virus(CaMV) replicate through reversetranscription just like retroviruses, but the viral particles
contain DNA instead of RNA.
2. The promoter of the 35S RNA is a very strong constitutive
promoter responsible for the transcription of the whole
CaMV genome.
3. Most widely used promoter in plant gene transfer.
4. Drives high level of expression in dicots
5. Its ideal for driving expression of selectable marker genes
and in some cases of reporter genes.
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Inducible Promoters:
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Inducible Promoters:
The activity of these promoters is induced by
the presence of biotic or abiotic factors.
The expression of genes operably linked to them
can be Turned On or Offat certain stages of
development of an organism or in a particulartissue.
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Desirable features of a inducible
promoters:
1. No expression of Trans Gene in the absence ofinducer
2. It should be specific to inducer- only one or one
class of inducer.3. The inducer should be non toxic
4. Induction of gene expression should be rapidfollowing the application of inducer
5. Induction of gene expression should ceaserapidly following the withdrawal of inducer
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Types of inducible promoters:
Three types:
1. Non plant derived systems
2. Plant derived systems that respond to
environmental signals
3. Plant derived systems based on developmental
control of gene expression.
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1. Non plant derived systems
A. Tetracycline
B.Ethanol Inducible
C.Steroid Inducible
D.Copper Inducible
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A. Tetracycline Tetracycline is used to either De- Repress Or Inactivate
Gene Expression
De- repression:
Tetracycline repressor (TetR) binds to tet operator- negative
regulation
Tetracycline act as a inducer- activation / de
repression.
Inactivation:
TetR is modified to an activator called Tetracycline Trans-
activator (tTA). tTA binds to operators and induces gene expression in absence of
tetracycline
When Tetracycline is present , tTA is released and expression
ceases.
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Alcohol inducer: The ethanol utilization pathway of the filamentous fungus
Aspergillus nidulans is a well-characterized positive operon system.
It controls the cellular response to ethanol and other related
chemicals.
The first enzyme in the pathway is Alcohol Dehydrogenase I
encoded by the alcA gene.
The transcriptional activator protein AlcR binds target sequences
within the alcA gene promoter in the presence of ethanol, ethyl
methyl ketone or other alcohols/ketones.
These compounds act as inducers of the gene expression.
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Alcohol inducer: This system uses Chimeric promoters
core 35S promoter
region + promoter containing binding sites ofAlcR
Transcription factor from Aspergil lus nidulans
This allows constitutive expression.
Ethanol act as a inducer-AlcR binds to promoters and
activates transcription
Syngenta has several patents and patent applications in
Europe and Australia directed to the transcriptional system
containing the alcohol dehydrogenase I (alcA) gene promoter
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Steroid Inducible
Modified transcription factor capable of binding with steroidinducer acts as activator of chimeric promoters
The mammalian Glucocorticoid Receptor (GR) is a member
of the family of animal steroid hormone receptors.
GR also acts as a transcription factor by activating genetranscription from promoters containing Glucocorticoid
Response Elements (GRE)
A system comprised of the GR and GREs resulted in transient
expression in tobacco
Dexamethasone, a strong synthetic glucocorticoid used asinducer.
Oestrogen and ecdysone are other inducers
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Steroid Inducible
Numerous patent and patent applications are
directed to steroid-responsive promoters for
the modulation of gene expression in plant
and animal cells
McGill University patents on promoters based
on the Rat Glucocorticoid Receptor (GR);
Rockefeller University patents on promoters
based on the Human Estrogen Receptor (ER);
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Copper Inducible
This system is based on Metallothionein genes
from yeast.
Upon binding Copper, the transcription factor
binds to Chimeric Promoter and activates theexpression.
Promoters derived from Metallothionein genes
from yeast, mouse and human are the subjectmatter of several United States patents granted
to Genentech and University of California
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2. Plant derived systems that
respond to environmental signals
Wound inducible
Heat shock inducible
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1. Wound inducible
The nos promoter (nopaline synthase) is wound inducible
in both vegetative and reproductive organs.
The induction of the nos promoter was observed in leaves,
stems, cotyledons, and various reproductive organs,
suggesting that the response is not organ specific.
The wound response was further enhanced by addition of
auxins.
Nopaline synthase promoter is wound inducible and auxin inducible. G An, M A
Costa and S B Ha (http://www.plantcell.org/content/2/3/225.abstract)
http://www.plantcell.org/content/2/3/225.abstracthttp://www.plantcell.org/content/2/3/225.abstract7/30/2019 Plant Promoters
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Wound inducible
The promoter, found in potato plants, regulatesa gene encoding the serine-type proteinaseinhibitor II (PinII).
PinII is constitutively expressed only in tubersand young floral buds of potatoes
PinII expression can be induced by mechanicalwounding in leaves
Methyl- jasmonate mimic wounding-as inducer
Used fro expression of pest resistant genes
http://myip.cctec.cornell.edu/techdocs/D1155.D1155_Wound_Inducible_Promoter_
Tech_Brief.pdf
http://myip.cctec.cornell.edu/techdocs/D1155.D1155_Wound_Inducible_Promoter_Tech_Brief.pdfhttp://myip.cctec.cornell.edu/techdocs/D1155.D1155_Wound_Inducible_Promoter_Tech_Brief.pdfhttp://myip.cctec.cornell.edu/techdocs/D1155.D1155_Wound_Inducible_Promoter_Tech_Brief.pdfhttp://myip.cctec.cornell.edu/techdocs/D1155.D1155_Wound_Inducible_Promoter_Tech_Brief.pdf7/30/2019 Plant Promoters
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2. Heat shock inducible
HEAT SHOCK ELEMENT(HSE) MEDIATED HEAT SHOCK INDUCIBILITY
Soybean heat-shock promoter Gmhsp17.3
Temp. shock of - 400 C produced 10k to 20k nbr of copies of
heat shock protein The promoter of the HSP18.2 gene from Arabidopsis, encoding a
heat shock protein, indicated that it functions as a strong
inducible system in plants
1. Comparison of different constitutive and inducible promoters for the overexpression of
transgenes in Arabidopsis thaliana.Holtorf S, Apel K, Bohlmann H.(
http://www.ncbi.nlm.nih.gov/pubmed/8541491 )
2. Gene silencing using a heat-inducible RNAi system in Arabidopsis (http://hal.archives-ouvertes.fr/docs/00/11/95/62/PDF/BBRC_HAL.pdf)
3 Plant derived systems based on
http://www.ncbi.nlm.nih.gov/pubmed?term=Holtorf%20S[Author]&cauthor=true&cauthor_uid=8541491http://www.ncbi.nlm.nih.gov/pubmed?term=Apel%20K[Author]&cauthor=true&cauthor_uid=8541491http://www.ncbi.nlm.nih.gov/pubmed?term=Bohlmann%20H[Author]&cauthor=true&cauthor_uid=8541491http://www.ncbi.nlm.nih.gov/pubmed/8541491http://hal.archives-ouvertes.fr/docs/00/11/95/62/PDF/BBRC_HAL.pdfhttp://hal.archives-ouvertes.fr/docs/00/11/95/62/PDF/BBRC_HAL.pdfhttp://hal.archives-ouvertes.fr/docs/00/11/95/62/PDF/BBRC_HAL.pdfhttp://hal.archives-ouvertes.fr/docs/00/11/95/62/PDF/BBRC_HAL.pdfhttp://hal.archives-ouvertes.fr/docs/00/11/95/62/PDF/BBRC_HAL.pdfhttp://www.ncbi.nlm.nih.gov/pubmed/8541491http://www.ncbi.nlm.nih.gov/pubmed?term=Bohlmann%20H[Author]&cauthor=true&cauthor_uid=8541491http://www.ncbi.nlm.nih.gov/pubmed?term=Bohlmann%20H[Author]&cauthor=true&cauthor_uid=8541491http://www.ncbi.nlm.nih.gov/pubmed?term=Bohlmann%20H[Author]&cauthor=true&cauthor_uid=8541491http://www.ncbi.nlm.nih.gov/pubmed?term=Apel%20K[Author]&cauthor=true&cauthor_uid=8541491http://www.ncbi.nlm.nih.gov/pubmed?term=Apel%20K[Author]&cauthor=true&cauthor_uid=8541491http://www.ncbi.nlm.nih.gov/pubmed?term=Apel%20K[Author]&cauthor=true&cauthor_uid=8541491http://www.ncbi.nlm.nih.gov/pubmed?term=Holtorf%20S[Author]&cauthor=true&cauthor_uid=8541491http://www.ncbi.nlm.nih.gov/pubmed?term=Holtorf%20S[Author]&cauthor=true&cauthor_uid=8541491http://www.ncbi.nlm.nih.gov/pubmed?term=Holtorf%20S[Author]&cauthor=true&cauthor_uid=85414917/30/2019 Plant Promoters
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3. Plant derived systems based on
developmental control of gene
expression
Senescence Specific Gene Expression
ABA Inducible Gene Expression
Auxin Inducible Gene Expression
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Senescence Specific Gene Expression Senescence inducible promoters fromArabidopsis genes- SAG12 & SAG13( Senescence
Associated Gene)
An ipt gene(isopentenyltransferase) undercontrol of the senescence
specific SAG12 promoter significantly
delayed developmental and postharvest leaf
senescence in mature heads of transgenictobacco .
Similar result in In lettuce
n uc e ene
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n uc e eneExpression
Abscisic Acid (ABA), an inexpensive, non-toxic,
natural substance can be used as a highly effective
chemical inducer
ABA is mediates a wide variety of stress responses
in plants and induces abscission in leafs during thefall season of the year.
Eg: The promoter of the barley ABA-responsive
HVA22 gene
Functional dissection of an abscisic acid (ABA)-inducible gene reveals two
independent ABA-responsive complexes each containing a G-box and a novel
cis-acting element.(http://www.ncbi.nlm.nih.gov/pubmed/7734964)
A i I d ibl G
http://www.ncbi.nlm.nih.gov/pubmed/7734964http://www.ncbi.nlm.nih.gov/pubmed/77349647/30/2019 Plant Promoters
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Auxin Inducible Gene
Expression
Auxin plays an essential role in a wide variety of plant growthand developmental processes, such as shoot and lateral rootformation, apical dominance, tropism, and senescence
A large number of auxin-inducible genes have been clonedand characterized, includingArabidopsis, soybean
hypocotyls, pea epicotyls etc
Examples:
1. The auxin-inducible soybean GH3 gene
2. ARGOS, a novel auxin- inducible gene that is involved in
organ size control inArabidopsisAuxREs( auxin response elements) combined with 35S core
promoter
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Reference:
1. Plant Biotechnology-The genetic manipulation of plants
by Adrian Slater and others
2. Introduction to Plant Biotechnology, by H. S. Chawla
3. Cellular And Biochemical Science edited by G. Tripathi