by Alyssa Mae Santos | Hachimoji
Agriculture plays a crucial role in the economy of the Philippines as it provides a source of income, food, and raw materials to Filipinos. Currently, we are facing the challenge of ensuring global food security despite challenges such as increasing human population, biodiversity loss, and climate change. To meet the demands of society, various genetic techniques used in plant cultivation have been developed to increase plant yield and nutrition.
Crop Improvement
Crop improvement involves the genetic alteration of plants to meet human needs. There are two techniques used in crop improvement. The first is selection which has been used for thousands of years wherein farmers deliberately chose and isolated their best crops to be planted to control the gene pool. The other technique is breeding wherein plants were crossed to produce offspring with the desired traits of both parents. In the 1900s, scientists began to discover the importance of locating genes on chromosomes and how it affects offspring traits leading to developments of various techniques to improve crops.
Marker Assisted Selection (MAS) is a technique in plant breeding wherein molecular markers are used to indirectly select important genes to improve precision and efficiency in breeding. Another important aspect in crop improvement is the use of plant genetic resources (PGR) which are genetic material of plants such as seeds, pollens and, the DNA. This can be used to give access to a range of genetic diversity in breeding while preventing the loss of useful genes by storing agricultural resources in genebanks.
Classically Bred vs Genetically Modified Crops
Traditional plant breeding includes a variety of techniques such as mixing the genome of the parent plants to be randomly re-assorted to the genome of the progeny. However, in doing so, undesirable genes can also be transferred while some genes can be lost, causing unintended effects on the offspring. Back-crossings are then conducted to fix the problem which is time-consuming.
Meanwhile, genetically modified crops allow introduction of new traits with more precise control wherein only the desired genes are transferred to the plant. Other advantages of genetically modified crops include the production of crops with enhanced yields and nutritional quality. Drought-resistant, disease-resistant, flood-resistant, and pest- resistant crops can also be developed, which in turn help provide food sustainability.
Methods in Creating Genetically Modified Crops
Genetic engineering is the manipulation of DNA to make a desired change in an organism. It can be used in various fields such as research, medical diagnosis and treatment, industry, and agriculture. One application of genetic engineering is the development of genetically modified crops (GMCs) using recombinant technology. Using this technology, there is a transfer of DNA from one species to another, allowing the development of desired traits in plants, which are not naturally-occurring. GMCs can either be cisgenic, wherein genes used are from within the same species, or transgenic, wherein genes used are from another species.
Gene gun
One technique in developing GMCs is the use of a gene gun that enables target genes to be shot into plant cells at a high velocity. This uses microprojectiles of small metal particles that are coated with recombinant DNA which is the resulting DNA when nucleic acid sequences are combined in the laboratory. The particles then penetrate the cell and the DNA is integrated to the plant’s DNA.
Use of Agrobacterium
Another technique uses bacteria called Agrobacterium that have the natural ability to transfer genes. First, the tumor inducing DNA (T-DNA) found in the circular DNA plasmid is removed to be replaced by the desired foreign DNA. Afterwards, the modified plasmid is reinserted into the bacterium, which acts as a vector to enable the T-DNA containing the foreign gene to be inserted to the plant cell. Finally, the plant cells are grown in culture resulting in a new plant.
CRISPR-Cas9 technology
Genome editing is another type of genetic engineering which allows precise modification of DNA in a host genome. There are various genome editing strategies, one of which is the use of CRISPR-Cas9. This technology stands for clustered regularly interspaced short palindromic repeats which are DNA sequences found in the genomes of prokaryotes. To use CRISPR, target genes that determine the phenotype of interest in the plant such as resistance to herbicides or pesticides are first identified. Using guide RNAs, the Cas9 is directed to this target gene which will be edited. CRISPR can be used for crop improvement to create GMCs, as well as non-GMCs wherein only the intrinsic DNA of the target species is modified.
Over the past decades, the use of genetically modified crops have become more prominent. The most popular GMCs include soybean, maize, cotton, canola, potato, and more. When these crops were first introduced, there were questions from the public regarding the safety of consumption. But through careful and thorough testing, the safety of these GMCs are ensured before being approved for commercial cultivation and utilization. Thus, genetically modified crops are safe to eat just like their non-GMO counterparts.
With the use of various genetic techniques such as genetic engineering, genetic editing, and MAS, challenges in agriculture such as population growth, pests, and crop diseases can be resolved. This showcases the important role of genetics in ensuring food security and crop improvement to develop crops with increased yield, nutritional value, and stress resistance to provide for the needs of society.
Posts
0 Comments