Genetically Modified Organisms-Bt Crops

Introduction 

The crops whose genes have been modified in some way or the other are generally known as genetically modified crops. 

Bt crops are regarded as transgenic crops because they secrete the same toxin  as that produced by the bacterium, Bacillus thuringiensis (short form is Bt), in the cells of plants, protecting them from various pests. The same bacterium is known to secrete some specific proteins, which are commonly known as “cry proteins”. These cry proteins are toxic for insects. Some examples of Bt crops are brinjal, corn and cotton.

The cry proteins present in plants help crystallise the digestive system of insects when they feed on these plants. This leads to the death of insects. However, these don’t affect the human digestive system in any way. 

Bacillus thuringiensis

Let us know more about Bacillus thuringiensis. It is a spore-forming, gram-positive bacteria mostly present in the soil. As we mentioned above, it secretes a protein that is confirmed to be toxic for insects. Some farmers during organic farming use this bacterium mixed with a solution and then spray it on plants to save them from pests. 

The use of Bacillus thuringiensis started in the early 1990s when it was applied with small proportions of genes from this bacterium. This helped in the secretion of cry proteins in the cells of plants. These were used to destroy pests that can destroy plants such as southwestern and European corn borer, cotton and tobacco budworm, and Colorado potato beetle. Bacillus thuringiensis is used to protect plants from such dangerous pests.  

Genetically Modified Organisms – Bt Crops Classification

All the Bt crops are classified majorly into two groups – Bt cotton and Bt brinjal. Let’s know about these genetically modified crops in detail.

Bt Brinjal

Bt brinjal is produced by the genetic modification of crystal protein genes that come from the same bacterium that is  Bacillus thuringiensis. If we look into the reason for the emergence of Bt brinjal, it was mainly developed to resist lepidopteran insects. The proteins that are given by Bt genes get easily attached to the receptors that are available on insects’ membranes. This results in the creation of pores on the surface of the membranes. This in turn affects the digestive system of insects. 

Bt Cotton

Just like Bt brinjal, the Bt cotton classification is genetically changed with the Bt gene which is used to save the plant from a significant cotton pest named bollworm. The worms that are available on the leaves of Bt cotton turn lifeless and sleepy, and therefore, it causes little less destruction. When those worms slowly grip the plant, the toxic proteins that are secreted by the crops are ingested, thereby destroying them.

Advantages of Genetically Modified Organisms Bt Crops

• These help enhance yield by destroying some pests that are harmful to plants. This way, these crops increase farmers’ income and contribute to increased production on farms
• Bt crop farming contributes to better and more productive agriculture in smaller areas
• These genetically modified organisms help in minimising soil pollution
• Farmers can enjoy healthier crops and disease-free plants with these crops
• Bt crops help protect insects that are beneficial for the ecosystem

Disadvantages of Bt Crops

• These genetically modified organisms are costlier than regular crops as these require more attention and hard work
• According to some researchers, the Bt gene might disrupt the natural gene flow process

Are Bt-engineered crops and Bt-treated crops safe for animals and humans?

Bt is among some pesticides that are considered safe for humans and other animals dependent on crops (i.e. vertebrate animals). As natural pesticides, these genetically modified organisms play an essential role in organic agriculture. Currently, Bt and its cry toxins are used everywhere for plants. Many researchers have confirmed that it is entirely safe for intake by humans and animals. Being natural pesticides, these have far less impact on the environment than chemical pesticides. 

Bt Crops in India

Bt brinjal was the first crop that was made by gene modification. It was the first insect-resistant plant in India. The Maharashtra Hybrid Seed Company first introduced it – it was also called MAHYCO. Monsanto is one of the world’s foremost seed manufacturers that helped develop the product.

The farming of brinjals (or eggplants) in India has often been obstructed due to a major pest, Leucinodes orbonalis, or the eggplant shoot borer. An extensive inspection led to the development of Bt brinjal. 

 Later on, there were many arguments against Bt crops in India. After much research and study, it was concluded that these are entirely safe for daily life. Also, it has been proven that these reduce soil pollution because there is no chemical involved.

Conclusion

As we discussed above, Bt crops are mainly developed by transforming genes. The primary purpose of these crops is to protect plants against pests. Although Bt crops are safe to consume by humans, they may be harmful to insects.  Bt crops come with advantages and disadvantages, as discussed above. Nowadays, these crops are in high demand. According to researchers, these are safe for humans.