bacillus thuringiensis cotton bt cotton
DESCRIPTION
INTRODUCTION OBJECTIVE WHAT IS BT COTTON WHAT IS BT? HOW Bt Cotton WAS DEVELOP METHOD ADVANTAGES OF BT COTTON DISCUSSION (our last minute result, not perfect tho)TRANSCRIPT
UNIVERSITI TEKNOLOGI MARA
NEGERI “fill” KAMPUS “fill”
Bacillus thuringiensis Cotton
MIC000
“course name”
NAME OF PARTNERS:
1 2010
2 2010
3 2010
4 2010
5 2010
DATE: 00/00/0000
LECTURER NAME: MISS
GROUP: AS000
DIPLOMA IN “fill”
FACULTY OF APPLIED SCIENCE
INTRODUCTION
Bt Cotton is a genetically modified cotton crop that has one or two genes of a soil
bacterium inserted into the seeds of cotton. Genes from Bacillus thuringensis is inserted to the
plant. These genes allow the plants to produce toxins which specifically affect certain groups of
insects. These genes allow the plants to produce toxins which specifically affect certain groups
of insects.
Bt cotton, or Bacillus Thuringiensis cotton, is used the same as any other cotton. The
only difference is that it has a protein genetically added which is identical to that of B.
thuringiensis bacteria which is toxic to many caterpillars, especially Lepidoptera species.
Therefore it is an economically important "built-in" insecticide.
Bt Cotton as containing a bacterium called Bacillus Thuringiensis (Bt). The spores of Bt
produce crystal proteins which are toxic to many forms of insects, leading to its use as an
insecticide. Bt is found throughout the world in a variety of soils in very small amounts
producing thousands of different strains of Bt.
Bt Cotton is a genetically engineered form of natural cotton. The main advantage of
utilizing biotechnology in agriculture are the possibilities of increase in productivity through
the use of newer varieties that possess properties such as resistance to pests, diseases, and
other stressful conditions like drought, salinity, or water logging. Of these measures, imparting
the property of insect (specific) resistance through the transfer of a gene from Bacillus
Thuringiensis (Bt) into target plants by modern biotech methods is presently considered to be
one of the most advanced applications of biotechnology.
OBJECTIVE
1. To study the effects of transgenic cotton in the field.
2. To study the effectiveness of Bt cotton against the pink bollworm and other insects,
its yield and cultural characteristics, insect resistance management, and how the
cotton works in combination with other control measures.
3. To control the pest that harmed cotton.
4. To decrease the usage of chemical pesticides
WHAT IS BT COTTON
Bt Cotton is a genetically engineered form of natural cotton. The main advantage of
utilizing biotechnology in agriculture are the possibilities of increase in productivity through the
use of newer varieties that possess properties such as resistance to pests, diseases, and other
stressful conditions like drought, salinity, or water logging.
Bt Cotton is produced by inserting a synthetic version of a gene from the naturally
occurring soil bacterium Bacillus thuringiensis, into cotton. The primary reason this is done is to
induce the plant to produce its own Bt toxin to destroy the bollworm, a major cotton pest. The
gene causes the production of Bt toxin in all parts of the cotton plant throughout its entire life
span. When the bollworm ingests any part of the plant, the Bt cotton toxin pierces its small
intestine and kills the insect.
WHAT IS BT?
The insect- disease- causing organism Bacillus thuringiensis (Bt) is a naturally occurring soil
borne bacterium found worldwide. A unique feature is its production of crystal-like proteins that
selectively kill specific groups of insects and other organisms. When the insect eats these
Cryproteins, its own digestive enzymes activate the toxic form of the protein. Cryproteins bind to
specific receptors on the intestinal walls and rupture midget cells. Susceptible insects stop feeding
within a few hours after taking their first bite, and, if they have eaten enough toxins, die within 2 or
3 days.
Different Bt strains produce different Cryproteins, and there are hundreds of known strains.
Scientists have identified more than 60 types of Cryproteins that affect a wide variety of insects.
Most Cryproteins are active against specific groups of in often create other problems, such as higher
populations of beet armyworms and cotton aphids and an increased pesticide load in the
environment. Frequent exposure of insect pests to insecticides results in the development of
insecticide resistance, which reduces the overall effectiveness of available insecticides, increases
crop losses, and leads to higher pest control costs and lower farm profits. The severity of tobacco
budworm and bollworm infestations and resistance to synthetic insect Bollworm larva feeding in
bollcides vary across the Cotton Belt, both between and within the states.
Because of this variation and the price of the technology, not all areas of the Cotton Belt
are able to economically justify the use of Bt cotton. However, where insect infestations are severe,
Bt cotton offers a new management tool for producers, helps ensure against yield loss in the
presence of heavy infestations of insecticide-resistant tobacco budworms, and aids in reducing
bollworm damage from Insects, such as the larvae of certain kinds of flies, beetles, and moths.
For example, Colorado potato beetle larvae are affected by Cry3A proteins, Cry1Ac is used
against tobacco budworms; and European corn borers can be killed with Cry1Ab, Cry1F, Cry1Ac, and
Cry9c proteins. Other Cryproteins are active against mosquito larvae, flies, or even nematodes.
Some Cry-proteins have been used for more than 30 years in various liquid and granular
formulations of natural Bt insecticides, mainly to control caterpillars on a variety of crops. The Bt
cotton varieties presently used against tobacco budworms, bollworms, and certain other
caterpillars produce the Cry1Ac protein.
HOW Bt Cotton WAS DEVELOP
About ten years ago, Monsanto scientists inserted a toxin gene from the bacterium
called Bt (which is the nickname for Bacillus thuringiensis) into cotton plants to create a
caterpillar-resistant variety. The gene is DNA that carries the instructions for producing a toxic
protein. The toxin kills caterpillars by paralyzing their guts when they eat it. Plants with the Bt
toxin gene produce their own toxin and thus can kill caterpillars throughout the season without
being sprayed with insecticide. Because the toxin is lethal to caterpillars, but harmless to other
organisms, it is safe for the public and the environment. Bt cotton produces an insecticidal
protein (Cry1Ac) from the naturally occurring soil bacterium Bacillus thuringiensis (Bt) that
protects the cotton plant from certain lepidopteran (caterpillar) insect pests. Coker 312 cotton
was transformed to express the Cry1Ac gene from Bt, resulting in cotton plants that were
resistant to attack from major lepidopteran pests. Bacillus thuringiensis (or Bt) is a Gram-
positive, soil-dwelling bacterium, commonly used as a pesticides the the Cry toxin may be
extracted and used as a pesticide. B. thuringiensis also occurs naturally in the gut
of caterpillars of various types of moths and butterflies, as well on leaf surfaces, aquatic
environments, animal feaces, insect rich environments, flour mills and grain storage facilities
During sporulation, many Bt strains produce crystal proteins (proteinaceous inclusions),
called δ-endotoxins, that have insecticidal action. This has led to their use as insecticides, and
more recently to genetically modified crops using Bt genes. Many crystal-producing Bt strains,
though, do not have insecticidal properties.
Biotechnologists created Bt cotton by inserting selected exotic DNA, from a Bt
bacterium, into the cotton plant’s own DNA. DNA is the genetic material that controls
expression of a plant’s or an animal’s traits. Following the insertion of modified Bt DNA into the
cotton plant’s DNA, seed companies moved the Cry-protein trait into high performance cotton
varieties by traditional plant breeding methods. Agronomic qualities for yield, harvest ability,
fiber quality, and other important characteristics were preserved at the same time the Cry-
protein gene was added to commercial varieties.
METHOD
Genetically engineered products
The concept of genetically engineered products has been in existence for quite long
before we knew them to exist. For instance insulin gene derived from the intestines of pigs is
inserted into bacteria. This bacterium grows and makes insulin, which is purified from the
bacterial culture and used medically. The same is true of the thyroid hormone, which, until
recently, was derived only from animals. Once again, genetic engineering enabled this hormone
to be cultured in the bacteria.
How was Bt Cotton produced? So what is a GM crop?
Genetic Modification of crops is one method of biotechnology - allowing individual characters
(genes or ‘traits’) to be transferred into crop plants.
Genetic Improvement through Biotechnology
1. Identify genes of Bacillus thuringiensis (Bt) with desired traits
2. Make copies of genes
3. Transfer to target plant tissue, cotton
4. Regenerate plant
5. Analysis and safety testing was done
6. Varieties of toxin are produced by using back-cross technique
7. Field testing to confirm its successfulness
8. Approval and commercialism
The three primary components of the genetic package inserted into cotton DNA include:
Protein gene
The Bt gene, modified for improved expression in cotton, enables the cotton plant to
produce Cry-protein. The first varieties of Bt cotton produced in the United States contained
one Cry-protein gene—Cry1Ac. Other varieties contain a “stacked” gene complex, for example
— one gene for insect control (Cry1Ac) and one gene to protect the cotton from application of
the herbicide glyphosate. Future cotton varieties may include these genes, other genes that
allow the plant to produce different Cry-proteins, or insecticidal proteins from sources other
than Bt. There are many possible combinations for crop improvement traits.
Promoter
A promoter is a DNA segment that controls the amount of Cry-protein produced and the
plant parts where it is produced. Some promoters limit protein production to specific parts of
the plant, such as leaves, green tissue, or pollen. Others, including those used in Bt cotton and
certain Bt corn varieties, cause the plant to produce Cry-protein throughout the plant.
Promoters can also be used to turn on and turn off protein production. Current varieties of Bt
cotton produce some Bt protein throughout the growing season.
Genetic marker
A genetic marker allows researchers to identify successful insertion of a gene into the
plant’s DNA. It also assists plant breeders in identifying and developing new cotton lines with
the Bt gene. A common marker is an herbicide tolerance gene linked to the Bt gene. Following a
transformation attempt to place the Bt and marker gene into the plant’s DNA, plants are
treated with herbicide. Plants that were successfully transformed have the Bt gene and the
herbicide resistance gene and will survive herbicide treatment; plants without the marker gene,
and hence without the linked Bt gene, will be killed by the herbicide. This genetic package—a Bt
gene plus a promoter and marker—can be inserted into cotton plant DNA through a variety of
plant transformation techniques.
ADVANTAGES OF BT COTTON
1. Economic and Production Benefits
a. Bt cotton provided US farmers with an average net income increase of $20 and
increased the total net value of US cotton production by $103 million in 2001.
b. China, net revenue increases have ranged from $357/hectare to $549/hectare in the
three years studied when one compares Bt cotton with non-Bt cotton.
c. In South Africa, smallholder farmers in the Makhathini region raised their yields and
reduced their application costs, netting an economic advantage for Bt cotton
growers of about $25-51/hectare.
2. Environmental Benefits.
a. Bt cotton can substantially reduce the number of pesticide sprayings, which can
provide significant environmental benefits.
b. Bt cotton adoption can provide secondary positive environmental impacts such as
i. Saving on raw materials needed to manufacture chemical insecticides.
ii. Conserving fuel oil required to manufacture, distribute, and apply such
insecticides.
iii. Eliminating the need to use and dispose of insecticide containers.
3. Does not affect beneficial insects such as honey bees, lady beetles, spiders, big eyed bugs,
pirate bugs, and parasitic wasps.
4. Benefits for Smallholder Farmers
a. At the macroeconomic level, the increased productivity can stabilize production and
reduce risks for lenders.
b. At the farm level, improvements in the insect control system being used can
positively impact the quality of life for farmers and their families by increasing
incomes, reducing insecticide sprayings, and offering savings in time.
c. Increased the yield of Bt cotton and farmer income.
DISCUSSIONThe only successful approach to engineering crops for insect tolerance has been the
addition of Bt toxin, a family of toxins originally derived from soil bacteria. The Bt toxin
contained by the Bt crops is no different from other chemical pesticides, but causes much less
damage to the environment. These toxins are effective against a variety of economically
important crop pests but pose no hazard to non-target organisms like mammals and fish.
Three Bt crops are now commercially available: corn, cotton, and potato. Bt toxin is
insecticidal only when eaten by the larvae of specific host insects. Unlike Bt commercial
formulations that must be targeted against a range of larvalinstars through optimally timed
applications to cover the larval feeding sites, transgenic Bt cotton has a consistent built-in
delivery system present in plant tissues where newly hatched larvae normally feed.
High levels of resistance to ACB depend upon an adequate titer of Bt protein being
expressed in these tissues. Neonates of ACB prefer specific feeding sites in cotton, and initially
establish in the terminals, top new leaves, floral buds, match-head squares, and white flowers.
Our results indicate that all of these tissues expressed sufficient Bt protein to provide significant
protection from ACB feeding. These results also show, however, that survival increased as the
plants aged, especially for the GK-2 cultivar. This phenomenon was also observed for the cotton
bollworms H. armigera and H. zea. Increased survival in each species may be attributed to the
decline in protein expression as the growing season progresses.
Historically, ACB has been a sporadic pest of cotton. Recently, however, spring planting
of several ACB hosts, especially corn, have been widely reduced in the cotton planting areas.
This change in the cropping ecosystem has resulted in a higher incidence of ACB on cotton since
the late 1980s. The efficacy of transgenic Bt cotton, expressing Cry1Ac or Cry1A proteins, to
several major cotton pests such as the tobacco budworm, Heliothis virescens (Fabricius), cotton
bollworm, H. zea, H. armigera, fall armyworm, Spodoptera frugiperda (J. E. Smith) and pink
bollworm, Pectinophora gossypiella (Saunders), have been demonstrated previously. Data from
this study indicate that both Monsanto Bt cotton NC 33B and Chinese Bt cotton GK-2 provide
significant season-long protection against ACB infestation in the field. In addition, higher larval
survival was observed on GK-2 than NC 33B in assays with the late season tissues.
Transgenic Bt cotton has been widely adopted in north China. It offers satisfactory
control of major lepidopteran insects including cotton bollworm and pink bollworm. However,
with millions of hectares of transgenic Bt cotton grown yearly, the possibility of insects
developing resistance to Bt toxin needs to be addressed to ensure the sustainable use of Bt
cotton.
One important principle of existing resistant management plans for Bt crops is that the
Bt plants express the toxin at high and consistent levels, referred to as a ‘high-dose’. Data
suggest that NC 33B and GK-2 appear to meet this criterion for ACB during early mid-season.
However, an equally important component of a resistant management plan is the provision of
non-Bt host plant (refuges), where local populations can survive and ultimately mate with
potentially resistant strains, producing offspring that are susceptible to the Bt plants.
Field corn is one of the major host plants of cotton bollworm and ACB and could be
considered as a refuge because both pests usually move between corn and cotton. However, Bt
corn is being introduced into China with ACB also being the primary pest targeted by this
technology. The first-generation transgenic Bt corn designed to target the European corn borer
Ostrinia nubilalis (Hu¨ bner) and ACB express the Cry1Ab protein, similar to the Cry1Ac and
Cry1A proteins found in Bt cotton.
RESULT
In first generation of ACB (Asian Corn Borer )was attack the Bt . cotton at several places
such as buds , and new leaves . Another things is ,few plants were bored by third or late-instar
lavae that cause the plant tissue to die.Besides the ACB that attack the Bt. Cotton plant ,we
have another type of pest that will cause the plant to totally die and wilt that is Ball worm . So
to solve the problem , Bt. Cotton was culture to prevent and controlling the Bt. Cotton plant
that infection by ACB and Ball worm . The result before we culture the Bt . cotton ,is showing
the incresing no of plant that were infected by the ACB and Ball worm .
The result in second generation of this palant show it will increses totally damaged by a
larvae by ACB pets . We do the experiment ofcultured Bt. Cotton in 2 years to campare the
population change in no of infected plant that cause by ACB and Ball worm . The result show
the number of dead plant is being decreased after the tecnique of cultured Bt. Cotton was
applying . But the result is totally not accurate . Apart from taht , the percentage of plant that
having infection also different with 2 years .
But in the third generation show the the ABC larvae was attacked new leaves and and
green balls . The result demonstrate ACB larvae that are susceptible to Bt toxin expressed in n
ew leaf ,bud , and petal tissue of transgenic Bt. Cotton plant .
CONCLUSION
As the conclusion , the function of Bt. Cooton that cultured to the plant can give us more
benefits such as will decreasing the number of plant that was infected by the pest such as ACB
larvae , Ball worms and caterpillars . Bt. Cotton also avoid the plant from wilt and died. It will
save the population of Bt. Cooton in the future . Apart from that , the Bt.cotton was cultured to
create caterpillars resistence variety . The gene of DNA that carries the instruction of producing
the toxic . The toxic kill the caterpillars and others pest by paralyzing their guts when they eat
the palnt . Besides that , the ways use the tecnique of Bt. Cooton that were cultured is not
become harm and dangerous to the ours enviroment and its plant . This tehnique is more eco-
friendly and give more benefits to others . Lastly Bt. Cotton often benefits to economic ,
production , enviromental . It also not affecting benaficial insects and benefits for smallholder
farmers .