Better Genes for More Crops

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Attempts to advance the quality and traits of living organisms, specifically plants, initiated thousands of years ago. They are not all human endeavors though; they also include natural evolution. This means that the characteristics of living organisms have changed over the ages. They have adapted to the surrounding environmental conditions and the selectivity features that work in favor of the individual, developing the most supreme and strongest characteristics to resist harsh environmental conditions.

Gene editing in plants aims to increase their nutritional value and fruit size, as well as enhance their ability to resist diseases and pests, prolonging their shelf life, and maximizing their adaptation potentials to the surrounding environment. Nutritionists and geneticists have agreed that, for each genetically modified plant, it must have three essential characteristics, which are to be genetically different from all other lineages, compatible with its species, stable and insusceptible to mutations.

Techniques

Using several methods, people have succeeded in improving plant's genetic characteristics; either by providing it with a new, good trait, or by removing a weak, harmful one. One of the most recent and well-known methods is "cross-breeding", which first appeared in 1700. The idea relies on pollinating two sexually compatible plant species to create a hybrid lineage, such as plum and apricot, lemon and grapefruit (tangelos), and radish and cabbage.

The researchers also derived the "mutagenesis" technique from nature, which is the alteration of plant genetic information. It is well known that genetic mutations may occur automatically when exposed to chemicals or radiations, and may result in lineages carrying genetic diseases or cancer. Mutations can also be processed in a laboratory by separating, altering, or adding genes or nucleotides. The first recorded mutation attempt was in the first half of the twentieth century; it resulted in a color change of the grapefruit.

One of the most important techniques of genetic modification is "protoplast fusion". It is a hybridisation-like process that takes place in the laboratory, not the farm, where scientists combine the contents of two genetically different plant cells, after removing their cell walls. Polyethylene is then added to help the two cells stick together. Scientists continue adding other supporting materials after the adhesion is complete, to complete the fusion process and the exchange of genetic information, resulting in a new hybrid. Plant hybridization experts use the "polyploidy" technique to control crop characteristics, such as the cultivation of seedless watermelon. Eukaryotes—organisms whose cells have a nucleus enclosed within membranes—have two paired sets of chromosomes, such as humans. Some plants, on the other hand, have more than two aired sets of chromosomes, known as polyploidy.

There is also the "genome editing" method, which is also known as genetic engineering. Scientists can add, cut, or replace genes within seed cells through the nucleus enzyme, which works as a scissor for molecules for its ability to edit, remove, and add nucleotides. It is totally created in the laboratory to be located exactly on the target gene or traits. One of the most prominent applications of this technology is the production of crops resistant to harmful herbicides.

In addition to the above-mentioned techniques, there is the "microinjection", where researchers inject DNA directly into plant cells. Many of the injected cells do not survive, but some would grow as a genetically modified plant incubating the new DNA. Likewise, in the "electroporation" technique, scientists apply a high electrical field to the cell plasma membrane to easily allow introducing DNA molecules that carry the needed traits to the cell. Subsequently, these cells recover and rebuild their walls, which were destroyed by the electrical field, to grow and multiply as a genetically modified plant. There are several methods and techniques that researchers are developing, such as transgenesis, microbial vectors, and cell selection.

These techniques share and intersect in many occasions, as one of them might suit a particular trait rather than the other; however, they all certainly develop the agricultural process, and produce crops with better traits. Scientists have proven that genetic modification is not science fiction, and that the idea of genetically modified foods and crops aims to serve humanity and eliminate nutritional problems around the world.

Controversy

The controversy is deepening and widening between the supporters of popularizing genetically modified food technology and their opponents. Each has a persuasive point of view supported by benefits and strengths. Scientists supporting the genetic modification theory, state several advantages of the technology, including the increase of the nutritional value of crops; such as Golden Rice. It is one of the first genetically modified crops, and was strengthened to treat vitamin A deficiency, which is common among developing countries and results in blindness and some infectious diseases, and can cause death among children. Other crops, such as maize, broom-corn, and bananas—were subjected to vital fortification with vitamins and minerals, to increase their nutritional value, in addition to having a better flavor.

The production of disease resistant lineages that are less demanding of pesticides, or requires less toxic and expensive species, is among the most important advantages of plant genetic modification. Pesticides cause undesirable effects to the environment, and to farmers' and consumers' health alike. Genetically modified plants produce toxic proteins that resist larvicides, and soothe viruses and plant fungi. Although these genetically modified seeds are more expensive than regular seeds, the total cultivation cost is overall reduced, as the cost of agricultural machinery, fuel, and chemical pesticides decrease; that is in addition to the resulting savings from crop yields. The pollution rate of water networks and drains in agricultural lands is greatly reduced, due to the lack of pesticides that previously spread widely over lands, and were mixed with irrigation and drainage water.

These crops are also characterized for being resistant to drought and water shortage, which makes them suitable for cultivation in several harsh places suffering from seasons of low supplies of water. They do not also require a lot of agricultural fertilizers, which reduces the total costs of the cultivation process. Moreover, they grow and ripe in a short period, and have long shelf life compared to regular crops that damage quickly. Genetically modified foods shine as well in the medical field; they can be used in the manufacture of immunizations, vaccines, and other several drugs. The characteristics of some of these crops, which could have caused serious diseases, such as cancer in the case of the potato plant, have become less cancerous when fried or exposed to extreme heat.

Genetically modified foods are, of course, subject to several accusations; some scientists have several concerns, and have attributed the emergence of some new diseases to genetically modified foods. Their concerns are represented in a number of points; such as the spread of allergies in a more exaggerated way than previously. The scientists' explanation of this phenomenon is that the planted genes in the modified crops may be from a plant or an allergen ingredient, and their insertion in several other crops has led to the spread of an allergic reaction. The World Health Organization (WHO) has asked genetic engineers not to use genes if they cannot prove that they are not allergens.

Modified crops are also accused of being one of the causes of the high prevalence of cancer rates, due to the occurrence of mutations in the DNA of the modified plant. However, the American Cancer Society denied these allegations, saying that it is inconclusive and needs further study. Physicians also attribute antibiotic-resistant bacteria that affect humans to eating modified foods. Their theory is based on the transfer of the gene responsible for disease resistance to human cells, then to the cells of intestinal bacteria, leading to the creation of new bacteria lineages that are antimicrobial resistant. The WHO reports that there is little chance a gene transfers from food to human cells or bacteria.

Several groups in the society fear genetically modified foods, and have concerns over the creation of mutations, or novel, untreatable and uncontrollable diseases. Yet, the society accepts natural mutations, which may be caused by the exposure of living organisms to chemicals or radiations. There is no doubt that there are several flaws, as well as several advantages. It is, thus, necessary to compare the great benefits, the problems that can be eliminated, and the potential risks, and apply various experiments before generalizing or banning the idea of genetically modified plants.

References

biotech-now.org
frontiersin.org
ippc.int
medicalnewstoday.com
medlineplus.gov
ncbi.nlm.nih.gov
resourcesmag.org

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