GM plants and techniques of genetic modification
Genetically modified plants are plants that have had their genes changed or modified so that they have a pacific characteristic that the plant would not otherwise have or would be rare, so it is easier and faster to use genetic modification to grow specific plants.
There are many techniques for genetic modification and in this report I will I show the most common ones below and I will highlight them in yellow so it is clear to see the separate techniques.
Transport by bacteria
This technique is when a bacterium is used to introduce the new gene that will lead to the plant developing the desired characteristic. One of the most common types of bacteria’s used for this is Agrobacterium. Agrobacterium is modified with the genetic information it needs and introduces the new gene into the plant cell. This can be used to infect a whole plant or protoplasts.
*A protoplasts is a plant cell that has no longer got a cell wall as it has been removed to make it easer to insert the new DNA.
*The plant cells walls are removed by enzymes.
*After the DNA has been entered into the protoplasts their cell wall will grow back and from.
*Then a plant will fully grow from clumps of cells called calluses.
(Fig 1)
From the picture on the other page you can see that the gene which will produce the desired characteristic is inserted into the plasmid which will be inserted into the bacteria.
*A plasmid is a molecule separated from the and capable of many replucations. (2)
Using a virus
In gentic modification in plants viruses can be used as a vector to add the required gene to the DNA of the plant cell. The plant is then grown from the plant cell with the new DNA. (2)
(Fig 2)
Gene Guns
Small gold balls are covered in DNA ready to be inserted into a cell of a plant.
*The golden balls with the DNA are then fired with a gun into the cytoplasm of the plant where it finds its way into the nucleus of the plant cell.
* The new DNA becomes incorporated with the plants original DNA.
*The cells that have had this treatment are then selected so that thy can be grown most successfully. (2)
(Fig 3)
How it has been used so far
*The first stage of the genetic revolution is well underway in global agriculture. Last year farmers around the world planted an area twice the size of the UK with genetically modified crops. (3)
(Fig 4) (Fig 5)
*Long-lasting tomatoes; Long-lasting, genetically modified tomatoes came on to the market in 1994 and they were the first genetically modified food available to consumers. These new genetically modified tomatoes produce less of the substance that causes tomatoes to rot, so remain firm and fresh for a long time.
*Golden Rice was developed in 1999; golden rice is rice that produces pro vitamin A (βcarotene) in the grain. The reason for this is so that in countries and areas of the world where food is scarcer and their main diet is rice there will also be vitamin A to help towards a more stable diet. “According to the World Health Organization, dietary vitamin A deficiency (VAD) causes some 250,000 to 500,000 children to go blind each year. Blindness and corneal afflictions are but indicators of more severe underlying health problems: more than half the children who lose their sight die within a year of becoming blind.” (5)
Normal rice Golden rice
(Fig 6)
*Insecticide sweet corn; GM sweet corn was made so that farmers don’t needs to use to fight insects. “The genetically modified sweet corn is called Bt-corn, because the insect-killing gene in the plant comes from the bacteria .” (6)
GM farming Advantiges and disadvantiges
For Against
›The farmers can use less
pestisides so helps to protect the
enviroment.
›The farmer can grow more food
faster that will also last longer.
›In some cases food tastes better.
›As seen in the case of golden
rices the GM could help with
diet problems in less developed
countries. (7)
Views on GM farming
Against: “are we going to push nature into evolving 'super bugs and mega weeds' that will not be affected by current pesticides and herbicides? We are beginning to see 'super germs' because of our overuse of antibiotics, right?” (8)
For: “In reality, GM crop production can co-exist with other systems, as long as reasonable standards of purity are developed.” (9)
future implications
GM was first used to help the growers to protect there plants and crops from problems such as insects and plant killing diseases. The future of GM crops is to help the consumers directly in as many ways as posible. It is thought that GM could be used to reduce the bitterness in citrus fruits, reduce saturated fats in cooking oils, produce more flavorful foods, and even lessen the gassiness caused by beans. Also, add more vitamins in commonly eaten foods and they could even be used to remove the allergenic’s within certain foods. (10)
Ethical Issues
Rights and duties: most people belive that every one has rights, for example, to live, eat, sleep and to have there own freedom. Does this mean that there is a duty for more wealthy countries to proceed with GM so to help many people in the less privileged countries have there rights? This is a hard ethical question because it is up to the wealthier countries to make a decision although it could have bad effects on the less privileged countries in the long run.
Maximising the amount of good in the world: There is some evidence that GM crops could help maximise the amount of good in the world. Although, it is hard to tell, as there will have to be more research into the long term effects.
Making the decision: This means that the decision has to be made and it should not be for selfish reasons, for example, making money out of poorer counteries. But, to help these countries and at the same time we must stay responsible for our decisions.
Leading a virtuous life: Although, there are many variations of the meaning of this leading a virtuous life. I believe that in this case it means, what ever decision is made it should be for all the right reasons.
Althogh many belive GM farming is a bad and would be wrong. I belive that this could be due to lack of knowledge in certain areas and some cases. I belive that GM testing on crops and plants should be able to continue because without it we will not be able to determine how safe GM farming could be if it was to be utilised.
Pesticides
Pesticides are natural or man made chemicals that stop insect, mould, fungi, weeds, and bird and animal from prohibiting the growth of plants and crops. Pesticides also regulate the crop growth. (11)
The pesticides used today help produce most of our food in mass, at low prices, and all year around in almost every supermarket and shop that sell food. The main alternative to using pesticides is organic farming although there are many advantages and disadvantages to both ways of farming. (12)
Should non organic farming be used?
Advantages Disadvantages
›Using non organic farmming
more food can be made.
›The food is at a cheaper price.
›Food does not take as long to
grow.
›Food last longer
›Non organic food will not contain
any insects.
›Without the use of pesticides
45% of crops would be lost.
(13)
Whether you want to use pesticides or not could depend on personal preferences on how you like your food to look and taste. Athought it is better for the enviroment if less man made pesticides are used. This is because they can disrupt the food chain, for example, when the pesticide that is sprayed makes its way to rivers and lakes throught surface run off, effects the qualty of the water. Also, the sprays can affect the air and the atmosphere.
(Fig 7)
Pesticides are also responsible for some erosion, contributing to global warming, and killing many animals such as fish. For example, pesticides are becoming concentrated into the tissues of shellfish.
Future possibilities
In the future it is possible that new farming tactics could be developed such as covering crops in protective shelters and using sticky insect traps. It is also possible that in the future some plants could be genetically modified so that fewer pesticides have to be sprayed. This prevents the insects from eating them and the plant is already immune to disease. (14)
By Shane Marklew
