Agriculture: Recombinant DNA
How is recombinant DNA technology used in agriculture?
Recombinant DNA technology is defined as the tools and techniques which are used to transfer a gene from a cell of a member of one species to the genome of a different species, and has been found to have many applications in agriculture;
Producing crops with faster growth rates
Tolerance to climate change
Transgenic organisms (who are also referred to as genetically modified organisms, or GMO's) have been specifically engineered in order to produce desirable traits. Bioengineering is the combination of both biological tools and engineering tools in order to create a usable product, for example, a transgenic organism.
The use of Agrobacterium in agriculture
The soil bacterium Agrobacterium tumefaciens has been widely used in agriculture, as it has evolved the ability to penetrate cell walls with its plasmid and insert specific genes into the genome of the host cells.
The Ti plasmid in A. tumefaciens causes an infectious disease in plants known as crown gall disease, and despite this, scientists have gained the ability to control and make use of this phenomenon in order to produce GMO's which are desirable to humans.
A gene is cut from a foreign source, inserted into the Ti plasmid to make a recombinant plasmid, and returned to A. tumefaciens for cloning. The bacterial vector can then be cultured with plant cells that are susceptible to penetration by the plasmid, and following penetration of a host cell, the genes are inserted, transforming the host plant into a genetically modified plant.
Transgenic organisms engineered for resistance
A herbicide is a substance used to control weeds, ideally leaving a crop unharmed, however spraying herbicides on crops to kill the weeds will usually damage the crop itself
Herbicide-tolerant crops have been produced to combat this, a notable one being the glyphosate-resistant Roundup Ready© soybeans have a gene inserted into them from a bacterium; Roundup Ready crops are resistant to the herbicide of the same name, which contains glyphosate - a chemical which inhibits a biochemical pathway in plants, preventing them from producing essential amino acids and causing them to die
The bacterium Bacillus thuringiensis has been successfully introduced into cotton plants through recombinant DNA technology via CSIRO
The Bt cotton produced is a natural pesticide to the Helicoverpa caterpillar, which is known to damage crops in Asia, Europe, Africa and Australia
Faster growth rate
The AquAdvantage salmon© has been engineered using recombinant DNA technology, and has the capability of growing at double the rate of conventional Atlantic salmon
The GM fish grow to market size in a mere 16-18 months, as compared to the previous time frame of 3 years
Greater product quality and yield
Increase in quality (nutrition) in rice
The WHO (World Health Organisation) has estimated that approximately 120 million people suffer from a vitamin A deficiency, and one to two million die of it each year
To combat this, Golden rice has been engineered, a type of rice that has a high amount of beta-carotene in it (a precursor of vitamin A), and is what gives the crop its bright yellow-orange colour
Golden rice is manufactured using Agrobacterium