Bt cotton introduction production of bt.

Soil and environment bt cotton

1. VIVEKANANDA ART’S AND SCIENCE COLLEGE FOR WOMEN SANKAGIRI DEPARTMENT OF MICROBIOLOGY SUBJECT : SOIL AND ENVIRONMENTAL MICROBIOLOGY SUBJECT INCHARGE Dr.R.Dineshkumar , Assistant professor, Department of microbiology, VIASS Sankagiri SUBMITTED BY: M.Niveditha , Il M.sc Microbiology, VIASS, Sankagiri Topic:Bt Cotton

2. Introduction
Discovery Bt cotton
Production of bt cotton
Types bt cotton
Major pest of cotton
Mode of action of bt gene
Mechanism of insecticidal action
Advantages
Disadvantages
Conclusion Synopsis

3. The full form of bt is Bacillus thuringiensis . It is a bacteria that naturally produces a crystal protein that is toxic to many pest insects. These are the crops that are genetically engineered to produce the same toxin as Bt in every cell of the plant so that pests do not destroy the plants. When it is used by farmers it degrades within a week and sometimes just in one day. The widespread use of Bt crops, pests became bt resistance. This has become a greater threat to organic agriculture. All Bt cotton plants contain one or more foreign genes derived from the soil-dwelling bacterium, Bacillus thuringiensis ; thus, they are transgenic plants. Introduction

4. Discovery Bt was first discovered in 1901 by Japanese biologist Ishiwatari in silkworms.

He named it Bacillus sotto meaning bacillary paralysis.

In 1911, German microbiologist Ernst Berliner independently rediscovered it when he isolated it as the cause of a disease in flour moth caterpillars in Thuringia

B. Sotto would later be reassigned as B. Thuringiensis var. Sotto.

In 1976, Robert A. Zakharyan reported the presence of a plasmid in a strain of B. Thuringiensis and suggested the Amid’s involvement in endospore and crystal ation .

5. What is Bt Cotton? Bt cotton is a transgenic crop that has been genetically modified to express the genes from the bacterium Bacillus thuringiensis ( Bt ). These genes produce proteins that are toxic to certain insect pests.

6. Bt cotton is a genetically modified variety of cotton that produces an insecticide to combat bollworm. Here’s an overview of its production process: 1. Gene Identification and Isolation : The Bacillus thuringiensis ( Bt ) bacterium produces a toxin harmful to certain insects. Scientists isolate the gene responsible for this toxin. 2. Gene Insertion : The Bt gene is inserted into the cotton plant’s genome using techniques like Agrobacterium-mediated transformation or gene gun technology. Production of bt cotton

7. 3. Cultivation and Selection : The modified cotton cells are cultivated in a laboratory, and those that successfully integrate the Bt gene are selected. 4. Regeneration : These cells are grown into full cotton plants in tissue culture. 5. Testing : The Bt cotton plants are tested for effectiveness against bollworm and other pests, as well as for environmental and health safety. 6. Field Trials : Successful plants are then grown in controlled field trials to Bt cotton is a genetically modified variety of cotton that produces an insecticide to combat bollworm.

8. 7. Regulatory Approval : Bt cotton must be approved by regulatory bodies in the country where it will be grown. This involves extensive review of safety and environmental impact data. 8. Commercial Production : Once approved, Bt cotton seeds are produced and distributed to farmers. Farmers can then grow Bt cotton using standard agricultural practices. 9. Monitoring and Management : Continuous monitoring for resistance development in pests is crucial. Integrated Pest Management (IPM) strategies are recommended to sustain the effectiveness of Bt cotton.

9. Bt brinjal is also produced by genetic transformation of a crystal protein gene cry 1 Ac from the bacterium Bacillus thuringiensis . Bt brinjal was developed to provide resistance against lepidopteron insects. The proteins produced by Bt genes bind to the receptors present on the insect’s membrane, resulting in the formation of pores on the membranes. This disrupts the digestive process and leads to the death of the insect. Types of bt brinjal They help in controlling soil pollution as the use of synthetic pesticides is reduced. Bt crops help in protecting beneficial insects.
It can easily feed an increasing population due to increased yields in a short time. Advantages

10. Bt crops are costlier than naturally grown crops.
It can disrupt the natural process of gene flow. Disadvantages

11. Bacillus thuringiensis is a gram-positive, spore-forming bacteria which is mainly found in the soil. As stated above, it produces proteins that are toxic to insects. Organic farmers use this bacterium in a solution and spray it on the plants to protect them from pests.

The practice of using Bacillus thuringiensis began in the year 1996 with small quantities of genes from the bacterium. This facilitated the production of cry proteins in plant cells that helped to kill pests Pests like European and southwestern corn borer, tobacco and cotton budworm, pink bollworm and Colorado potato beetle largely destroyed the crop yields. Bacillus thuringiensis protected the crops against such pests. Bt cotton

12. Advantages of Bt -cotton • Yield superiority • Lesser need of pesticide • Better quality Disadvantages • Higher cost of seeds • Higher fertilizer and irrigation cost

13. The major pest of Bt cotton is the bollworm, particularly the pink bollworm ( Pectinophora gossypiella ). Other bollworms like the American bollworm ( Helicoverpa armigera ) and the tobacco budworm ( Heliothis virescens ) can also be significant pests. Bt cotton is genetically modified to express the Bacillus thuringiensis ( Bt ) toxin, which targets these bollworms, reducing the damage they cause. However, resistance to Bt toxin has been observed in some populations of these pests, necessitating integrated pest management strategies. Major pest of bt cotton

14. Mode of action of bt gene 1. Ingestion by Insects : When susceptible insects consume Bt cotton, they ingest the Bt protein. 2. Activation in Gut : The alkaline conditions in the insect’s gut activate the Bt protein, converting it into a toxic form. 3. Binding to Gut Cells : The activated toxin binds to receptors on the gut cells of the insect. 4. Pore Formation : This binding causes the formation of pores in the gut cell membranes. 5. Cell Lysis : The pores disrupt the gut cells, leading to cell lysis (bursting). 6. Insect Death : The damage to the gut ultimately causes the insect to stop feeding and die within a few days.

15. 1. Gene Introduction : The Bt gene is inserted into the cotton plant’s DNA. 2. Protein Production : The cotton plant produces a protein called Bt toxin. 3. Insect Consumption : When pests eat the cotton, they ingest the Bt toxin. 4. Toxin Activation : In the insect’s gut, the Bt toxin is activated. 5. Cell Damage : The activated toxin binds to receptors in the gut cells, creating pores and causing cell damage. 6. Insect Death : This disrupts the digestive system and leads to the insect’s death.
This process helps reduce damage from pests without the need for external insecticides. Mechanism of bt cotton

16. 1- The level of toxin expression can be very high, thus delivering sufficient dosage to the pest. 2- The toxin expression is contained within the plant system, hence only those insects that feed on the crop perish. 3-The toxin expression can be modulated by using tissue-specific promoters, and replaces the use of synthetic pesticides in the environment. The latter observation has been well documented worldwide Advantages Of bt cotton

17. Disadvantages of Bt -Cotton . 1-Cross Contamination Pollens from GMO plants they cross pollinate with grasses and weeds. This could develop “ superweeds ” that have the same resistance properties as the crops. 2-Allergies On The Rise The amount of childhood food allergies has risen significantly. The exact link to GMO has not yet been found, but many believe this is due to insufficient research in the area.

18. Conclusion Insect attack is a serious agricultural problem leading to yield losses and reduced product quality. Insects can cause damage both in the field and during storage in soils.

Each year, insects destroy about 25 percent of food crops worldwide. The larvae of Ostrinia nubilalis , the European corn borer, can destroy up to 20 percent of a maize crop.