Recently I took part in an essay writing competition, I found out today that I did not win, however I decided to share it to any who are interested in taking the time to read it, it's written in layman's terms so it should be quite easy to follow:
What scientific breakthrough should we focus on to provide sustainable food, energy and water for nine billion people on a planet of apparently finite natural resources, and why?
Science is the backbone of the modern world. Breakthroughs in the gathering of resources have enabled the population of the planet to continue expanding without calamitous collapse as predicted by Malthus in 1798. However, this equilibrium between supply and demand is tenuous and will be even more difficult to maintain with the predicted nine billion humans expected in 2050. One noteworthy breakthrough, in biology, could significantly ease mounting pressure.
This discovery draws from knowledge gleaned in precision genome engineering – improving plants by altering their genetic composition – through breeding and transgenics. In order to successfully do this tools that allow us to make precise changes are deeply needed.
Transcription activator-like effectors (TALEs), are a recent discovery (2009) originating from a plant associated micro-organism, Xanthomonas. TALEs offer to greatly extend our abilities in biology; they are nature’s own tools, not artificial proteins. They can be designed to bind to any specific DNA sequence and therefore can be used to improve any region of a genome, providing a successful approach to repairing faulty DNA inherited from previous generations in any species (2).
TALEs are transcription activators – they turn genes on in a controllable manner. TALEs evolved to function outside of Xanthomonas and inside of plant (or animal) cells. They target to the nucleus, the centre of the cell where the entirety of the DNA is stored. They bind DNA (see Figure 1 below) and then target promoters which activate the transcription or copying of a gene. TALEs can be engineered to transiently or stably activate a system, which makes them dynamic tools that can activate or repress a system, providing a method to control ‘problems’ at a DNA level by improving their genetic configuration.
Figure 1: Tal effectors binding a strand of DNA (2).
If agriculture is to supply the burgeoning population of the world, new crop varieties will have to be bred to supply the increasing demand. Increased demand will undoubtedly occur as both poverty decreases (and thus more people can afford to eat more) and the effects of climate change become more pronounced, decreasing yields.
TALEs can be used to swap damaged or ineffective genes for healthy or functional genes from the same species. Such an approach would likely provoke less controversy because plants produced by such an approach would contain no foreign DNA, they are likely to meet with greater public acceptance.
Addressing sustainable food is a key focal point for the 21st century. It plays the role of a lynchpin in terms of energy production and water use. This is because 70% of water goes to agriculture, more than all other sectors combined and fertilisers consume a third of energy input in crop production (1, 3). If plants requiring less water and less nitrogen fertiliser per yield tonnage were introduced through the use of TALEs, the stress induced by agriculture could be significantly curtailed and free up water for other sectors where it is vitally needed. This means that the environmental impact of our current overconsumption could be mediated in a positive fashion for both man and nature.
Ultimately, breakthroughs in biology will allow for the addition of desirable traits in plants, such as the introduction of successful plant metabolic strategies into current crop plants in order to improve yield and their tolerance toward poor soils. For example traits that increase water efficiency and decrease desiccation for water hungry species would be beneficial in drought wrought regions.
Another benefit: TALEs could be used to address the production of biofuels via synthesis of an alga capable of producing biodiesel in a highly efficient manner. This would fuel the automotive industry and help to wean it off of its addiction to oil and diesel; providing an elegant solution to the current release of CO2 emissions that continue to rise. Furthermore the price of oil fluctuates uncontrollably due to its position in unstable regions of the world. Having the means to produce biodiesel in a tank in one’s own country would provide energy security for many countries from an oil shock.
The patent licensing strategy for TALEs is benevolent; it offers research and application to developing countries for free. For-profit companies operating in countries in the developed world have to pay royalties, however they are much better equipped to pay. The technology is being licensed non-exclusively; the great benefit of this is that large corporations are not able to monopolise the technology and manipulate it to their own will.
The success of the technology is visible already; companies such as Syngenta are licensing the technology for R&D in the search for commercial uses in certain crop plants (2). This is just the beginning; TALEs have the potential to increase production of resources, but they also provide new avenues of treatment in other sectors of biology, such as medicine.
1. http://www.oecd.org/document/55/0,3746,en_2649_37401_44753399_1_1_1_37401,00.html
