WE HAVE EXPLOITED the world’s resources for thousands of years, and crops have been a major part of this. However, as crop yields begin to plateau, the world’s human population is increasing at an alarming rate. By 2050, it is predicted that the human population will have reached nine billion, and at current food production rates, we will not have enough food to support this many people.
It is predicted that, to support this population growth, crop yields will need to increase by 70 per cent. Combined with the effects of global warming, this is a huge concern across the globe. Clearly, new methods are required to increase crop yield, and genetic modification (GM) seems, to some, to be a sensible and viable answer. One way to improve crop yields is through GM crops. Many different manipulations have been carried out over time to improve various aspects of crops – Herbicide resistance, viral resistance and insect resistance. This can be done in a variety of ways but using agrobacterium tumefaciens is one of the most common methods .
This bacterium causes crown gall disease in plants, resulting in a proliferative mass that grows on the plant. A. tumefaciens can be exploited to make genetically modified plants using its native ‘Ti plasmid’. Part of this plasmid (the T-DNA) is transferred to plant genomes during infection and the surrounding sequences can be used to transfer any gene of interest. These sequences can be used to surround a gene, for example herbicide resistance on another plasmid with the T-DNA on the natural plasmid being deleted. This allows the genes that allow transfer to act on the gene as if it were T-DNA. The gene is transferred into the host plant and integrated into its genome, creating a transgenic plant.
This month, Rothamsted Research, in combination with the Universities of Essex and Lancaster, have been granted permission by the Department of Environment, Food and Rural Affairs to trial growth of GM wheat from 2017-2019. The application was submitted in November 2016. This specific wheat has been genetically modified to photosynthesise more efficiently (a very complex feat, as photosynthesis requires many different genes). One of the enzymes involved in photosynthesis is enzymesedoheptulose-1,7-biphosphatase (SBPase). The scientists involved in this project, funded by Biotechnology and Biological Sciences Research Council (BBSRC), have increased plant production of this enzyme by adding m o r e genes for it to wheat (2 or 6) from a relative Brachypodium distachyon.
This means they can covert light into biomass more efficiently and results in a greater crop yield. In greenhouses, these plants have been very successful, increasing yields between 20 and 40 per cent. Nevertheless, a field trial is needed to assess the suitability of these crops for the field, and in the long term, large-scale use.
However, many people are against the use of GM crops with many trials being destroyed by protesters in past years. Around 30 anti-GM groups have objected to the plans for the trial, such as GM Freeze. The main concern is that genes introduced into wheat may spread into the wider plant population. This is a big problem when developing herbicide resistant plants as weeds can become resistant, however in this case the threat is mild. Protesters argue that the money used for GM crop research could be invested in reducing food waste and poverty. Interestingly, after the Brexit vote, the government is re-evaluating its position on GM crop development. These issues have been on going for a long time, but it seems GM could be the way forward, despite controversy