Food security is becoming increasingly reliant on technological progress to develop solutions in the face of emerging issues. Genetic tools are promising candidates to alleviate some of the rising demand and improve crop yield with many applications and prospective innovations.
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The value of molecular techniques in agriculture
The golden age of molecular science has provided molecular tools that are often implemented to address the emerging challenges of contemporary agricultural systems.
The first genetically engineered plant, a tobacco plant, was developed in 1983. This was followed by the first genetically engineered food, the Flavr Savr tomato which was developed in 1994 alongside the first modifications of corn and soy that occurred at a similar time.
Since then, many molecular techniques have been implemented across modern agricultural practices.
Single nucleotide polymorphisms (SNPs) are widely used to identify genetic regions of interest, as employed to explore common traits between Asian and African strains of rice in 2019. Traits of interest in this study were heading date, tiller number at maturity, and grain weight, which are particularly valuable as they are key determinants for rice productivity.
However, the single most promising molecular technique in agriculture and food science remains the use of CRISPR-Cas gene editing.
Food and agricultural scientists have led a wide range of experiments on key crop types. Chinese scientists in 2015 were able to increase the drought and herbicide tolerance of soybeans. In 2016, another group was able to enhance the tolerance to biotic and abiotic stress of sugarbeet, which supplies nearly 35% of the sugar in the world.
In recent years, research has progressed continuously. A review from October 2020 on the use of CRISPR-Cas technology in agricultural science identified key research areas since the initial use of this gene-editing toolkit. Specifically, progress in increasing plant yield, overall quality, disease and herbicide resistance, plant breeding, and accelerating the domestication of crops were the most considered areas of research.
The review then discussed the most important breakthroughs, describing how modifying gene regulation, understanding mutagenesis, and developing directed evolution technologies, were the most significant contributions to the effectiveness of CRISPR-Cas technology. Such advances provided considerable support for further refining the reagent delivery as well as the precision of gene editing itself to minimize any off-target mutations, ultimately progressing CRISPR applications.
These improvements have reduced some of the pressure on crop demand as more resilient and productive crops provide yield increases to compensate for the growing population. With the inevitable progress in technology, the effectiveness of technology including CRISPR toolkits is expected to continue to improve.
Contribution of molecular tools to modern-day food security
The International Service for the Acquisition of Agri-Biotech Applications (ISAAA) states that 29 crops have received regulatory approvals for production and consumption in the USA. Currently, over 90% of corn, soybeans, and cotton are grown from genetically modified seeds.
The contribution of genetically modified crops is expected to increase primarily due to the increasing efficiency as well as the accessibility of genetic techniques. Indeed, a starter CRISPR-Cas kit is currently estimated at 65 USD, making it readily available for many researchers.
Although molecular tools may bolster crop production, certain limitations remain to be addressed. Genetic manipulation may not yet be able to be implemented across the considerable spatial and temporal scales of all agricultural systems. Additionally, the advent of rapidly evolving pests and pathogens that are resilient to pesticides and able to overcome genetic barriers of resistance may also represent a considerable and unpredictable challenge to genetically modified crop systems.
Finally, the genetic modification of crops remains controversial in many regions, with increasing skepticism relating to health and environmental concerns despite close regulation of genetically modified crops. Such disputes have led to certain discrepancies between regions that do not breed genetically modified crops, which may, in turn, increase the global vulnerabilities to pests.
This was particularly noticeable in a 2018 multi-country survey of consumer openness to genetically modified food across the US, several European countries, and Australia. Overall, the US had the largest acceptance with 56%, contrary to Belgium and France that had 46 and 30% respectively of participants, which were willing to purchase and consume genetically modified foods.
Nonetheless, the improvement of molecular techniques as well as approaches to policy development may help mitigate some of these limitations and continue the trend of implementing genetic tools.
Prospective applications in food science
Looking into the future, molecular tools represent considerable potential for food and agricultural research. The most notable contributions remain the improvement of crop resilience to abiotic and biotic threats. Additionally, further improvements on the growth cycle and selection of plants are key to refine as discussed in the previous review.
These changes are already well underway and are continuously developed. Moreover, the ability for plants to inherit CRISPR-related changes is particularly promising. Improving the inheritance of genetic modifications would provide further benefits.
Additional applications also include the progress of gene identification to better understand the life-history traits of species. One such example is the use of genome-wide association study (GWAS), which was used by scientists from the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences (CAS) to identify variations in nitrogen use in rice and published in January 2021. The findings are pivotal to enhance research in plant nutrition as nitrogen is a limiting factor in many plants, and the now identified gene, OsTCP19, may provide key elements to improving nitrogen efficiency in plants.
There are also numerous parallel applications of molecular tools alongside genetic modification of crops including the use of genetically enhanced pesticides as well as the modification of insects and pollinating vectors.
Additionally, the genetic engineering of animals is also being increasingly considered, with the first genetically engineered salmon made available for human consumption in 2015. This salmon grew nearly twice as fast due to the use of genetic material from the ocean pout, an animal that grows year-round, allowing the genetically engineered salmon to bypass the seasonal growth limit of typical salmon.
Therefore, many different areas of potential applications make molecular tools valuable to improving crop yield across agricultural systems. Finding new methods of application as well as improving and diversifying existing methods is of significant interest to enhance agricultural practices.
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