Bacillus thuringiensis strains have been used for designing bio insecticidal plants. A gene from this bacteria have insecticidal property which is transferred to cotton plants to produce Bt cotton which is resistant I to bollworm insect which is a major pest of cotton. Similarly insects affecting maize; cabbage, Sunflower etc., are also controlled by mutant strains of Bacillus thuringiensis bacteria.

Bacillus thuringiensis (Bt) strains have been used for designing novel Bioinsecticidal plants.

Bacillus thuringiensis (Bt) strains are a group of bacteria that produce crystal toxins known as Cry toxins. These toxins are highly specific against certain groups of insect pests, making them valuable for controlling insect populations. Bt strains have been extensively used in the development of bioinsecticides, which are environmentally friendly alternatives to chemical insecticides.

Bioinsecticidal plants are genetically modified plants that express the Cry toxins produced by Bt strains. These plants have been engineered to produce the toxins in their tissues, making them highly resistant to insect pests. When insects feed on these plants, they ingest the Cry toxins, which then bind to receptors in their gut, causing the gut cells to break down and leading to the death of the insect.

Advantages of using bioinsecticidal plants:
1. Reduced reliance on chemical insecticides: Bioinsecticidal plants provide an alternative approach to pest control, reducing the need for chemical insecticides that can have negative effects on the environment and human health.
2. Targeted pest control: The Cry toxins produced by Bt strains are highly specific to certain groups of insect pests, minimizing the impact on non-target organisms.
3. Increased crop yield: By controlling insect pests, bioinsecticidal plants can help increase crop yield and reduce crop losses caused by pest damage.
4. Cost-effective: Once bioinsecticidal plants are established, the need for repeated insecticide applications is reduced, leading to cost savings for farmers.
5. Environmental sustainability: Bioinsecticidal plants are considered environmentally sustainable as they have minimal impact on the environment and do not contribute to pesticide residues in food.

Examples of bioinsecticidal plants:
1. Bt cotton: Cotton plants genetically modified to produce Cry toxins have been successfully used to control cotton bollworm, a major pest of cotton crops.
2. Bt maize: Maize plants expressing Cry toxins have been developed to control pests such as the European corn borer.
3. Bt soybean: Soybean plants producing Cry toxins have been engineered to control soybean pod borer, a significant pest of soybean crops.

In conclusion, Bacillus thuringiensis (Bt) strains have been used to design bioinsecticidal plants, which offer targeted and environmentally friendly pest control solutions. These plants have been genetically modified to produce Cry toxins, providing a sustainable alternative to chemical insecticides and contributing to increased crop yield.