Bacillus killing the larvae of flour moths in Germany and published a description of the bacterium and its … Mycogen, another small biotechnology firm, instead cloned Bt genes and expressed them in an alternate host, Pseudomonas fluorescens, a bacterial species common in transgenic cotton.

Insect resistance transgenic cotton has been produced by inserting a piece of DNA from a bacterium.

Insect resistance transgenic cotton refers to genetically modified cotton plants that have been engineered to produce a protein toxic to certain insect pests. The DNA responsible for this insect resistance is derived from a bacterium called Bacillus thuringiensis (Bt). Bt produces a protein toxin known as Cry protein, which selectively targets specific insects.

Explanation:

Bacillus thuringiensis (Bt):
Bacillus thuringiensis is a soil-dwelling bacterium that naturally produces proteins toxic to certain insects. These proteins are known as crystal (Cry) proteins or delta-endotoxins. Different strains of Bt produce different types of Cry proteins, each toxic to specific groups of insects.

Insertion of Bt DNA into cotton plants:
To create insect-resistant cotton, scientists extract the gene responsible for producing the Cry protein from the Bt bacterium. This gene is then inserted into the cotton plant's genome using a technique called genetic engineering or genetic modification.

Expression of Cry protein:
Once the Bt gene is successfully inserted into the cotton plant, it becomes part of the plant's DNA. As the cotton plant grows, it expresses the Cry protein throughout its tissues, including the leaves, stems, and bolls.

Action of Cry protein:
When insects, such as certain types of caterpillars, feed on the genetically modified cotton plant, they ingest the Cry protein along with the plant material. The Cry protein then binds to specific receptors in the insect's gut, causing the gut cells to break down and leading to the insect's death. The Cry protein only affects insects that have the specific receptors targeted by the protein, making it highly selective and safe for non-target organisms.

Advantages of insect resistance transgenic cotton:
1. Reduced pesticide use: Insect-resistant cotton reduces the need for chemical insecticides, leading to a decrease in environmental contamination and potential harm to beneficial insects.
2. Increased yield: By protecting cotton plants from insect damage, the transgenic variety can result in higher crop yields and improved quality.
3. Cost-effective: Farmers can benefit from reduced expenditure on insecticides and increased productivity, making insect-resistant cotton a cost-effective choice.

In conclusion, insect resistance transgenic cotton has been produced by inserting a piece of DNA from the bacterium Bacillus thuringiensis. This genetic modification allows the cotton plant to produce the Cry protein, which selectively targets and kills specific insect pests, providing an effective and environmentally friendly method of insect control in cotton cultivation.