Altered, modified, improved, more beneficial, these are the kind of things that are always in vogue and appreciated. Speaking of agriculture and crops, genetically modified crops is one such trending topic -:
Genetically modified crops come from the plants in which new traits have been introduced by using modified genetic engineering techniques. These traits do not occur in the plants naturally. For example, these techniques can be used to create herbicide-tolerant plants, or plants giving higher productivity etc.
Origin of GMO
The very first GMO crop to be sold commercially was “Flavr Savr tomato” from California in 1994. This was a late ripening variety that improved upon tomato’s perishability. However, the high cost of production and lower yields resulted in the failure of this crop. The vast scale adoption of GMO crops started in 1996 in the US, China, Argentina, Canada, Australia, and Mexico.
Why do we need genetically modified crops??
With the day to day changing lifestyle, increasing population, increasing food demand, changing environment, etc, the need for genetically modified crops is rising. For instance:
- Farmers who are growing crops on a larger scale for commercial use cannot get rid of pests and insects easily, so there is a high requirement of crops which are insects and pests resistant. In this case, GMO could address these problems and also significantly increase the product yield. For example, Bt cotton did solve this problem for some.
- In Bt cotton, Bt stands for ‘Bacillus thuringiensis.’ It is a species of bacteria that has been used as an organic form of pest control for many decades. This particular form of bacteria is usually found in the soil, and it makes different types of proteins that act as insecticides. It targets mosquitoes, black flies, caterpillars, moths, and beetles. Despite acting as a natural pest control for all these insects, it is harmless to humans.
- However, recently, pink bollworm pests have developed resistance to Bt toxins and thus farmers have started resorting to using pesticides again even while growing Bt Cotton.
- Plants can be modified to be resistant to bacterial, fungal, or viral infestations for example bananas are modified to resist ( black Sigatoka) fungus which can reduce banana yield by 70%.
- Plants that can tolerate various environmental stress like drought, heat, frost, acid poor salty soil etc. for example- a new trait which can survive prolong water stress has been introduced in rice (salumpikit rice)
- The most critical part is to get improved nutritional value. Crops can be modified to contain nutrients that are lacking in the diet. For example golden rice – modified to have an enhanced level of vitamin A.
- GMO crops are chemical free and hence good for the environment. They have a longer shelf life, provide a stable and efficient way to sustain enough crops to feed the ever-growing population of people in the world. And the best part is that they are affordable. Since the yield is more, the prices can be much lower.
How do we insert a new trait/quality into a plant?
It is done in 2 steps :
1> For transferring the new trait in the crop a bacteria called Bacterium Tumifaciens is generally used. This bacteria has the ability to transfer DNA( carrying a new trait) between itself and plant. The trait of interest is first transferred into the bacterium by humans, and then the bacterial cells transfer it into the plant.
2> The plant cells which take the new trait successfully are then grown to create a new plant under appropriate light and temperature. This happens because plants have the capability of regenerating a whole new plant from a single cell. We had covered this phenomenon in our last week’s blog article on Plant Tissue Culture.
Downsides of using genetically modified crops:
1> Cross-contamination: plants which have resistance to herbicides can develop ”superweeds” by cross-pollinating with grass around and passing on to them the same resistance property as the crops.
2> GMOs have been modified to have antibiotic property to make them immune to certain diseases, once consumed and left in the body can make other antibiotics less effective.
3> there has been little testing and research done on long-term effects of GMO food. This makes it’s use for human consumption a risky proposition.
Usage of GMOs in present scenario:
1> Till now, more than a score of plants have been genetically modified and approved for commercial release. Majority of them are tolerant to herbicides or insects and pests resistant, example soybean, cotton, maize, potato, cotton, brinjal, etc.
2>Bt cotton is the first crop to be approved for commercial use in India. This lead to a rise of more than 75% increase in cotton growing areas. The production also increased from 150 lakh bales to 270 lakh bales. The yield shot up from 300 kg per hectare to 500 kg per hectare, making India the second highest cotton producer.
Off lately, the pests have started to develop resistance to genetically modified varieties too. In the last year’s incidence of pesticide-related death of 20+ farmers in Yavatmal district in India, the crop on which they had to use the pesticides was was Bt Cotton.
3> In 2011, 16.7 million farmers grew GMO crops on almost 400 million acres in 29 countries, 19 of which were developing countries. Importantly, 90% of the farmers growing GM crops were resource-poor, small-holder farmers and they produced almost half of the GM crops grown worldwide.
4>GMOs can increase productivity in agriculture. According to PG Economics, from 1996 to 2015, GMO crops are estimated to have contributed to an additional global production of 357.7 million tons of maize, 180.3 million tons of soybeans, 25.2 million tons of cotton and 10.6 million tons of canola. GM crops have contributed to higher yields, e.g., 30 percent more in some farming areas, and can contribute to poverty reduction and food security in developing countries.
5> plants are being modified to produce edible vaccines . for example:
- potato for -hepatitis B and cholera
- lettuce and rice for- measles
- tomato, tobacco, and potato for- foot and mouth disease.
Urvashi completed her B.Sc. in Biotechnology from SBS PGI College Dehradun and is currently pursuing Masters in Environmental Sciences (Natural Resource Management) from Doon University, Dehradun.
She is currently interning with CityGreens, and while at it, trying to spread the knowledge she has gained during her academic studies by writing for CityGreen’s University.