Once humans recognized that genes were responsible for the various features expressed in organisms, the foundation stone for transgenic plants was laid. The word “Transgenic” stands for any external genetic feature artificially introduced into the genome of another organism to get desired features. Various Recombinant DNA technologies are used to teach and screen the recombinants from the non- recombinants, ultimately giving us the plant the desired benefits. The “Flavr Savr” tomato was the first transgenic plant that made its appearance in the market, developed by Celgene. Even though this crop was unsuccessful commercially, it paved the way for developing other transgenic plants such as Bt cotton, Bt brinjal, and Golden rice. With the advent of new molecular biology techniques such as Crispr-Cas 9, the future of transgenic plants has unlimited potential.
Production of Transgenic Plants:
So to create a transgenic plant, first, we need to identify a helpful gene (this acts as our gene of interest) in an organism we want to insert into our plant. This gene is then extracted with the help of a restriction endonuclease enzyme( molecular scissors) and inserted into the target genomes. These insertions can be carried out by several methods such as-
- Particle Gun or gene gun or biolistics,
- PEG( polyethylene glycol mediated transformation),
- Agrobacterium-mediated gene transfer.
Generally, a small section of cells take up the gene of interest, and thus they are selected and regenerated into transgenic plants via tissue culture techniques.
Advantages and Importance of Transgenic Plants:
Any genetic recombination experiment is undertaken with a clear objective and needs in mind to be addressed. Thus the advent of transgenic plants has been essential in rejuvenating an already stretched agricultural sector. The advantages can be listed as follows:
- Improving Production yield
- Cutting down transportation costs
- Enhancing the nutritional values of already established crops.
- Preventing crop damage by producing herbicide, insect, virus, and pest-resistant crops.
- Development of drought-resistant crops.
The development of such transgenic plants will help reduce the environmental burden by reducing the use of weedicides, fungicides, and insecticides. It will be a massive benefit to the environment besides keeping up with the demand and a win-win situation for everyone.
Examples of Transgenic Plants:
A Few prominent examples of transgenic plants are as follows:
- Flavr Savr Tomato: It was the commercially grown first transgenic plant. This crop aimed to make tomatoes more resistant to rotting by introducing an antisense gene that interferes with Beta polygalacturonase. It would allow the farmers to regulate the ripening of the tomatoes at will by introducing ethylene externally. Ethylene is an essential plant hormone responsible for fruit ripening. This crop could not succeed in the market, as even though it had a positive effect on the shelf life of the tomatoes, it was still unable to affect the fruit’s firmness.
- Bacillus thuringiensis crops: A few examples of transgenic plants are Bt cotton, Bt corn, Bt potato, and Bt tobacco. These plants are genetically engineered to possess endotoxin, which prevents the action of various pests that belong to the order: Lepidoptera, Coleoptera, Hymenoptera, Diptera, and Nematoda. This endotoxin is elucidated from the cry gene in the bacterium. Its mode of action is via pore formation in the insect’s digestive system consuming it. Since this toxin is directed towards only the pest population, other organisms which are not harmful to the plants are spared, and hence it assists in conserving the field ecosystem.
- Golden Rice: It is a form of rice developed through genetic engineering that aims at solving the problem of Vitamin A deficiency. It is a second-generation transgenic crop, and it focuses on improving the crop’s nutritional content. The golden rice was created by transforming rice with two beta-carotene synthesis genes.
- Psy gene from daffodil
- Ctrl gene from the soil bacterium Erwinia uredovora
Ethics Related to Transgenic Plants:
Recombinant DNA technology comes with its fair share of ethical concerns and arguments. A few opinions or potential ethical problems that are raised in this debate against transgenic plants are:
- Potential harm to human health
- Undisclosed damage to the environment causes unpredictable results.
- The negative impact of traditional farming practices.
- Corporate dominance
- The unknown nature of the long-lasting effect of the technology.
RDT is a potent tool, and its misinterpretation or misuse can lead to unpredictable damage in the future. Thus one must be very careful while undertaking any project or product based on transgenic organisms.
Humans have always been curious, and this curiosity has led to many fascinating inventions and discoveries which have helped develop our standard of living. In the agricultural sector, development in the technology of transgenic plants is the way forward. Since pesticides and weedicides have already been used extensively, we are starting to see their side effects. Thus we need the development of better transgenic plants to sustain our growing population. The advent of CRISP brings a new ray of hope in this field. Equipped with such precise gene-editing techniques, we might produce better breeds of transgenic plants. One must also keep in mind that all these techniques and products have to be subjected to scrutiny and reviews as it is challenging to predict the long-term harmful effects of transgenic plants.