Currently, at 7.8 billion people as of March 2021, the global population is greater than ever. As the world’s population continues to grow exponentially, the middle-class population size increases; this, in turn, causes the global consumption of resources to increase. Due to this and the ever-growing magnitude of the global climate change crisis (which decreases crop production and the amount of land available for agricultural purposes), many of the world’s resources are in danger of being used up. Among these precious resources is food, one of the most vital sources of nutrition for the human population.
Food security is already an ongoing cause for concern in many areas of the world; the further aggravation of the climate crisis and the growing population can be expected to deteriorate this situation further. As the Internation Food Policy Research Institute states, for a population, food security exists when all people always have access to safe, sufficient, and nutritious food to meet their dietary needs and food preferences. Food security for a household means that it is accessible for all members to help them live a healthy, active life. Often, without these ideal conditions, one will be more susceptible to malnourishment; they possess a diet that lacks (i.e. nutrition deficiency or starvation) or has too many nutrients (i.e. obesity). These situations can be short-term or even long-term, producing famine in a particular region, leading to a lower life expectancy and an overall lower quality of life for the population.
Image is courtesy of The Organisation for Economic Co-operation and Development (OECD).
Luckily, scientific research has continually demonstrated genome editing's power using artificially introduced DNA-modifying enzymes in crops to help end world hunger and increase global food security. The Science Magazine explains that regular plant breeding used to be done through cross-pollination and self-pollination. However, genetically modified crops lead to higher crop yields, a reduction in the use of chemical pesticides, and an overall reduction of poverty and malnutrition in the areas in which this process is used. It is the use of this foreign DNA (deoxyribonucleic acid) in crops that lower the generally high rates of regulation involved in caring for these crops (i.e. soil quality, water quantity, etc.), which ultimately decreases the monetary and temporal costs of these once necessary procedures. As a result, this increases both the amount and the quality of crops produced. This process is believed to play a significant role in improving global food security by potentially drastically improving the global agriculture industry.
Genome Editing: What is it, and how is it done in crops?
According to the National Human Genome Research Institute, genome editing is a group of techniques proven to permit scientists and researchers to change an organism's DNA, the location of the cell's genetic material, through which traits are coded for. These traits can be physical, such as eye colour or hair colour, or even not visibly apparent, such as the risk for a particular disease. Usually, technologies used can act as scissors, removing any unwanted pairs of nitrogenous bases in the DNA sequence. Then, the DNA in that particular area can be replaced, removed, or added.
As the Institute for Food Laws and Regulations states, the most recent form of genome editing technology is CRISPR or Cas9 (ie. Clustered Regularly Interspaced Short Palindromic Repeats), developed in 2009. This form is less complicated, more efficient and accurate, and less expensive than older techniques. Consequently, this is the most used method of genome editing in crops. The production of genetically modified organisms requires inserting a new sequence of DNA into the plant's genome. In this, a family of DNA sequences found in the genomes of prokaryotic organisms known as the prokaryotic repeat cluster is inserted into a set of homologous genes (i.e. genes with the same relative position or structure). This improves the nuclease and helicase enzymes' visibility, which bind to the new and old DNA sequences and raise electrostatic forces of attraction between them, enabling them to bind together. It is important to note that CRISPR is used to insert or edit single nucleotides (i.e. components of DNA that form the fundamental structural units of nucleic acids such as DNA and RNA) from the crop's genome.
Image is courtesy of Vox.
The production of genetically modified crops usually involves the insertion of a DNA sequence from another cell, but crops can also be genetically modified without the insertion of unknown genes, explains IFL Science. This is done through the use of biological catalysts known as transcription activator-like effector nucleases (ie. TALENs), which are modified to bind to a specific DNA sequence. These enzymes are introduced into cells where the unwanted fragments of DNA sequences are deleted. Ultimately, specific nucleotide insertions and deletions can alter the general structure of the DNA sequence, altering the gene, its phenotypes, and the resulting traits of the crop.
Image is courtesy of Frontiers.
The Impact of Genome Editing in Crops
Genome Biology writes that editing the crop's genome or transferring genes across a species to achieve the desired traits is proven to positively affect the efficiency of seed production and enable the increased combination of various breeds of crops as well. This improves crop breeding methods and produces a large variety of phenotypes for a specific species of crops. It may potentially help increase the crops' resistance and resilience to atmospheric dangers, such as drought, flooding, allergens, and diseases, all while increasing their nutritional value.
However, this efficient and cost-effective way to improve crop yields does not come without risks and challenges. As Frontiers highlights, a crucial downside in using CRISPR technology is that the technology edits multiple DNA sequence sites simultaneously, increasing the chances of mistakes (i.e., a misplaced or missing nucleotide in the DNA sequence) in the genetic code. This increases the chances of gene mutation and decreasing crop quality.
Undoubtedly, this revolutionary technology has advanced crop production in the global agricultural industry for the better. It is a low-cost, effective way to increase the quality and quantity of crops grown. It truly is through scientific discoveries and research such as these that we can work to end world hunger and other important global issues alike sustainably.
Article Author: Aneri Buch
Article Editors: Valerie Shirobokov, Edie Whittington