plant biotechnology

1. i
PRE-ASSIGNMENT # 1
TOPIC: PLANT PROMOTERS
SUBMITTED TO: Dr. Samreen Mohsin
SUBMITTED BY: Bakhtawar Attique
MAJOR: Biotechnology
COURSE TITLE: Plant biotechnology
KINNAIRD COLLEGE FOR WOMEN,
LAHORE.
DATE: 10th
February, 2018

2. ii
TABLE OF CONTENTS:
Serial no Page numbers
1. Introduction 1
2. Promoter 1
3. Types of promoters control gene
expression
2
4. References 4
TABLE OF FIGURE CONTENTS:
Serial no Page numbers
1. Figure 2: Position of promoter 2

3. 1
1. INTRODUCTION:
Transcription is basically the conversion of double standard DNA into a single strand of RNA and
which convert the double stranded DNA into single strand of mRNA? RNA polymerase is the
polymerase which converts the DNA into messenger RNA, ribosomal RNA and transfer RNA
according to the required situation because DNA carrying a region which transcribed into RNA.
In eukaryotic transcription, the single RNA polymerase is unable to start the transcription it needs
some enhancers, chemical mediators, chemical modulators, activator, and repressors these are
proteins or nucleotides signals which give signals to other proteins come and attach at the site
transcription for the production of mRNA from DNA.
RNA POLYMERASE:
Three type of RNA polymerase I, II, and III. RNA polymerase I produces large ribosomal RNA
28s or 18s. RNA polymerase III produces transfer RNA and RNA polymerase III produce all the
functional protein bodies.
2. PROMOTER:
There are sequences in which transcription factors have an affinity and these DNA sequences are
known as promoters. And RNA polymerase bind with this sequence.
The promoters consist of the following parts:
i. TATA box: which is very important for recognition of RNA polymerase II. This part
slightly downstream.
ii. Initiator box: the stretch of nucleotide sequences from where the initiation begins. This
part is present at a downstream position.
iii. Upstream control elements: bind with RNA polymerase along with activator. This part
is present in an upstream position.
These three parts combine together to build a promoter. And the promoter maybe 200 or 300bp
long. The two types of factors attached with the three parts of the promoter generalized
transcription factors such as TF II and generalized transcription factors attached with the TATA
box and Initiator box other type of factor is specialized transcription factor and this factor attached
with upstream control elements and RNA polymerase.
DEFINITION:
A Promoter is basically a DNA sequence which initiates the transcription mechanism and activates
the transcription of the downstream DNA sequence. [1]

4. 2
Figure 2: Position of promoter.
TYPES OF PROMOTERS CONTROL GENE EXPRESSION:
NAME FUNCTION
1.Constitutive
promoters
These are active in all species and kingdom, they are not dependent on
developmental or environmental factors. As their expression is generally not
acclimatized by endogenous influence, and constitutive promoter promotes
expression in all tissue. It was first isolated from plant pathogens and used for
regulating gene expression in transgenes in plants. Examples: Pathogen promoters
(CaMV 35S promoter and Opine promoters) and Monocot promoters (Plant
ubiquitin promoter (Ubi), Rice actin 1 promoter (Act-1) and Maize alcohol
dehydrogenase 1 promoter (Adh-1). [1]
2.Tissue-
specific
promoters
They promote the expression in specific tissues and support the gene expression at
various developmental stages. Location of their expression is :
i. Vascular system.
ii. Photosynthetic tissues.
iii. Roots.
iv. Tuber.
v. Vegetative organs.
vi. Seed part.
vii. And reproductive organs. [2]
These locations are for heterologous systems (different species or kingdom) and
specificity found in homologous systems (same species, genus, family, and
kingdom. Examples: Root promoters, Fruit promoters, and Seed promoters.

5. 3
NAME FUNCTION
3.Inducible
promoters
This promoter is not affected by endogenous factors (internal factors) but they
affected by environmental surroundings and external stimuli. Response to various
stimuli: [1]
i. Chemical compound some organisms respond to this stimuli but some
did not respond to this stimuli.
ii. Antibiotics.
iii. Copper.
iv. Alcohol.
v. Steroids.
vi. Herbicides.
vii. Controlled by abiotic factors such as light, oxygen, heat, cold and
wound.
viii. And induction of gene expression independent of some biotic factors.
Examples:
i. Chemically-regulated promoters. [2]
ii. Physically-regulated promoters.
4.Synthetic
promoters
Form various origins by carrying together the primary elements of a promoter. By
activation of transacting proteins, they regulate the gene expression. These are
unrelated to their physical position of the target genes.
The regulatory part made up of:
i. Chemical inducible promoter. [1]
ii. Transactivation proteins.
iii. And Constitutive promoters.

6. 4
REFERENCES:
1. Bios.net. (2018). Inducible promoters. [online] Available at:
http://www.bios.net/daisy/promoters/271.html [Accessed 9 Feb. 2018].
2. Shukla (2018). Promoters in gene expression. [online] Slideshare.net. Available at:
https://www.slideshare.net/SmitaShukla1/promoters-in-gene-expression [Accessed 9 Feb.
2018].

7. 5