Understanding of genetics is very useful in environmental manipulation such as farming. manipulation of genes have been performed since ancient times to obtain most grain plants we use today such as wheat, corn and rice. Advancements in this process allow us to keep our population fed and allows us to grow to the current population we have.
However even with the current advancements, we will face a challenge in feeding our populations in the near future. This is estimated to be around the population of 10 billion people. So we have to consider whether biotechnology and DNA manipulation will help with this limitation of our current crops.
A major probem to our crops
A great obstacle to growing crops that we face today is that most plants are not able to grow in salty soil. Introduction of salt to soil happens too often. As we water plants daily we bring in dissolved forms of salts to the farm soil. Most of the time small amount of salt is washed away from rainfall, sinking deeper into the soil. This process of sinking salt is called percolation.
However in dry climates, there is less rain. So the process of percolation does not occur as often, and as time goes on the salt tends to build up in most dryland farming. This salt build up has always been a major problem to agriculture. This problem has been known to wipe entire civilizations due to starvation in the past. We are now also facing the same problem today as we lose more than 65000 acres of farmland every day to excess salt build up. The excess salt renders the land unusable for farming.
Mechanism of salt toxicity
There are two mechanisms in which salt effects plants.
1. It impairs the roots from taking up water from the soil. Since plants use osmosis to transport water, if the soil is more concentrated in salt the water tends to move from the plant to the soil. Essentially drying the plant in a hypotonic process.
2. Salt blocks several enzymes involved in important cellular processes. This happens when salt concentration interferes with protein folding. An incorrectly folded protein will not perform its function as intended, essentially killing the organism as a whole. Some of the most affected proteins are proteins that are involved with making other proteins and proteins involved in photosynthesis. This ensures that no protein is made properly and the plant can’t generate its energy source properly.
For those of you who don’t know what photosynthesis is; it’s basically a process by which a plant converts solar energy into stored energy in form of sugars, it is the primary way plants receive energy. The way we eat in order to gain energy. So salty soils takes away the plants energy and prevents it from exhibiting a phenotype.
They are very few plants that can thrive in salty soils. This does not include any of the major food crops we use to feed ourselves. This means there is currently no gene to resist salt in our major food sources. This is where biotechnology becomes essential to solve this major problem.
A very similar plant to our crops called the Arabidopsis has a salt resistant gene. This gene works by adding a unique mechanism to the plant that allows the plant to transport salt from the soil to vacuole storage in the plant cells. This storage is mostly located on the leaves of the plant. This prevents the salt from interacting with the roots and the osmotic transfer of water. Therefore damage to the plant is minimized with this process.
Even though this process seems like a possible cure to the salt obstacle, it has its limitations. Even though the plant gains small amount of resistance, in a very high concentration this system fails because the storage vacuoles rupture in the high concentration soil leading to plant death. With recent genetic modifications a vector was introduced to this process which enhanced its ability allowing the plant to survive in very high concentrations of salt.
Biotechnology allows us to transfer a gene from one plant to another. In a study when the enhanced salt tolerant gene from the Arabidopsis was transferred to a tomato plant. The resulting tomato plant was very salt tolerant as result. As an added benefit the salt was only stored in the leaves of the plant which means the tomatoes were still normal in the transgenic plant. Now if this process is repeated on the major crops we can solve a major problem of salty soil in farming in many places in our world. We can create farms out of barren wastelands and deserts. This is all possible because of biotechnology.
there is alot to consider when introducing biotechnology to our food. however it provides us with a possible short term solution to many of our problems. it is definitely something to consider for our future.