 This is your beautiful hobby garden and it's full of fruits and vegetables and flowers of various kinds. One fine morning you go out and find that half of your vegetable garden has been destroyed by these white caterpillar like things. You quickly google about them and find out that they're apparently called ball worms and they're known to be a menace. So you rush for that insecticide container hoping that it will take care of this infestation. But then you wake up the next morning only to find that these ball worms are still demolishing your garden because they are insecticide resistant. Now what? How do we deal with this situation? What can we possibly do to fix this ball worm problem? Well, the solution lies with genetic engineering and a bacterial species. In this video we will be talking about BT crops and how they can actually solve our problem over here. Bacillus thuringiensis which is a very long name and quite a mouthful to be honest. So let's just stick to BT. So bacillus thuringiensis or BT is a soil bacterium which is found pretty much everywhere in the world. So chances are it's also there in our garden soil. So these little fellows have a secret. They can produce a bunch of toxins that target very specific insects. Insects that usually wreak havoc in crop fields like these pesky little ball worms over here. These toxins are called the insecticidal crystal proteins or simply the cry proteins encoded by the cry genes. Now cry proteins are pro toxins meaning that they are present in their inactivated forms inside the bacteria. When they are ingested by the ball worms then these proteins get activated into the toxins by the alkaline pH of the insects digestive juice. So like just like how we have digestive juices these insects also have a gut juice or a digestive juice and the pH of that juice is really really high and it is this very high pH that will activate the proteins into the toxins. Now the activated toxins aka the proteins will now bind with these certain receptors which are present on the surface of the epithelial cells of the gut. So these are the epithelial cells you can see in yellow and then we have the blue receptors and these boxes that you see the rectangles in pink these are the cry proteins. So you can see that kind of like a lock and key mechanism they have bound with the receptors present on the cell surface. Now what happens after this is that once they have bound together like this it's going to create pores in the epithelial cells. So wherever you can see the binding there will be these pores. So these cells become perforated. And when that happens these other proteins or these other toxins which are present all around it can now easily enter the cell. So all these extra proteins they will now enter into the cell. And because of that what happens is more and more toxins or proteins enter penetrate and enter the cell the cells swells up like a balloon and soon they burst open or they lies. And because of this eventually this keeps on happening with all the epithelial cells of its gut. So after a point all of this damage will eventually kill off these ballworms and we would get our garden back to its original glory. But how exactly do we use these toxins? Do we extract the proteins out of these bacteria and use it as an insecticide? Well you can. In the olden days that is exactly what the farmers did. They made insecticides out of these cry proteins. But we have better options now available to us. So genetic engineering allows us to create these things called GMOs or genetically modified organisms. Using this technology we can insert the cry genes which are responsible for coding the cry proteins. We can take those genes and insert them directly into the plant's DNA kind of like this. So the red DNA is the DNA of the tomato plant. I have kept it as red because it was easier. And these yellow lines that you see over here these are the cry genes. So we can insert the cry genes directly into the plant's DNA and then the plant itself will start producing these toxins or the cry proteins with zero help from anyone else whatsoever. Does that mean that you have to insert bacterial genes into your plants? Of course not. Unless you're a scientist with a huge lab in the right set of tools then yes, sure. But for average people like you and me we can just go to the market and get these upgraded variants instead of the normal plants. GM plants or genetically modified plants are quite easily available in the market these days so we don't really have to worry about that. But wait, you can't just pick any GM variant that you want. You have to be very very careful what you get because cry genes and proteins are super insect specific. That means different toxins target different insects. For example the cry proteins cry1ac and cry2ab. Now these two cry proteins they work specifically against or they target cotton ballworms. So we insert these genes or the genes which encode these proteins into the cotton plants and then this plant will become BT cotton. Then there's one more cry protein called cry1ab. Now this one is very specific towards these things called corn borers which are these caterpillars that can wipe out mace fields or corn fields. So this cry protein will target those corn borers and so we're going to insert the gene that encodes this protein into the mace plants and then we're going to get BT mace. So if we have to replace this tomato plant over here with its GM counterpart or its upgraded counterpart then we'll have to look for that BT tomato plant which will specifically the tomato destroying ballworms. We need to be very very careful about that. So you've probably guessed it by now that whenever we're adding these cry genes into the plant's genome then that plant becomes a BT plant or a BT crop and today these BT crops are resistant against a large number of insects and pests. Most of which include members of three major families the beetle family the butterfly family of which ballworms are a part of and the fly family and these BT crops have revolutionized the world of agriculture especially in India about 80% of all the cotton that is harvested is BT cotton. Now after all of this one thing might still be bothering you you may you may say that hey we we are working with bacterial toxins here what if we eat these variants so we have a tomato variant over here these yellow dots they signify that it's upgraded because it has the cry genes so what if we eat this tomato variant and we get affected too I mean these genes or these proteins are killing insects so they will definitely do something to us right well not really us humans and other vertebrates and even beneficial insects like bees we don't get affected by these cry proteins why because we don't have the receptors for these cry proteins so if there are no receptors then there will be no binding if there is no binding then there will be no damage so it is 100% safe to consume all the consumable variants of vegetables and fruits with which have like the plants if they have cry genes they are still completely safe because we won't be affected by them at all so now you can quickly go to the market and get these GM plants worry-free and return the glory of your super awesome garden once again