Using Ethanol to Help Plants Better Handle Heat Stress
What is Ethanol?
Ethanol is a clear, colorless liquid with the chemical formula C2H6O, and is commonly referred to as alcohol, ethyl alcohol, and grain alcohol. Ethyl alcohol is a volatile and flammable liquid and has a wide variety of industrial and home applications due to its miscibility with water and other organic compounds. Most ethanol produced in the United States is produced from starchy crops, such as corn, via the fermentation of sugars by yeast or ethylene hydration processes.
Global Warming and It’s Impacts on Plants
Global warming has been a hot topic among scientists, however, what are the causes and consequences of it? Global warming is long term increase in Earth’s surface temperature since the 1850’s that is primarily a result of burning fossil fuels. When fossil fuels are burned, they release a large amount of carbon dioxide (CO2), a greenhouse gas, into the atmosphere. This gas traps heat in Earth’s atmosphere that causes increases in the surface temperature commonly referred to as global warming. These greenhouse gases can remain trapped in the air for decades to hundreds of years.
Global warming can have serious impacts on human health and life, one of which is our food supply. When surface temperatures increase, plants and crops are vulnerable to heat stress that can cause them to die. This has a negative impact on our food supply as high temperatures cause vital plant processes to be compromised. Photosynthesis, a process in which plants use sunlight to synthesize food from carbon dioxide and water, decreases with elevated temperatures. Additionally, respiration (an important process that releases energy to fuel growth) is continuous which means the food reserves of the plant can be depleted. Lastly, high temperatures can cause desiccation when transpiration exceeds water absorption in the roots. If this persists, the leaves of the plant will begin to wilt and eventually die.
Using Ethanol to Treat Plants
There have been studies performed to examine the implications of global warming on heat related yield losses in agricultural crops globally. One study found that without genetic improvements and adaptation, “each degree-Celsius increase in global mean temperature would, on average, reduce global yields of wheat by 6.0%, rice by 3.2%, maize by 7.4%, and soybean by 3.1%.”
One effective method to reducing losses of crops is genetic engineering, however, this is costly and would require years of research. A promising alternative to this is to pre-treat crops with safe chemicals that increase the heat tolerance of crops. Scientists have recently found that exposing a low concentration of ethanol to soil for several days and exposing it to temperatures high enough to cause heat stress, increased the survivability of these plants. This could result in a very significant increase in the use of ethanol in the agricultural industry.
Researchers have also been able to identify a set of genes and biochemical processes that are activated by treatment of soil with ethanol. They found that there was an increase in production of a protein, Binding Protein-3, a stress adaptation in the endoplasmic reticulum (ER). The triggering of the stress response in plants offsets the effects of misfolding proteins that occur during environmental stress such as heat stress. This shows a very promising use of ethanol that could protect the human food supply. Successful studies were performed using an ethanol concentration of 3%, which can be made by diluting higher concentrations of ethanol with deionized (DI) water.
