On pages 85-87, Dr. Moalem talks about the relationship between plants and their resistance to consumers or lack there of. This connects well to BIG Idea 1, which states "The process of life drives the diversity and unity of life". He talks about potatoes and their use of solanine.
Discuss why it would be beneficial for a potato to have solanine and why some high levels make it bad for humans to eat. Connect to the evolution unit as to why potatoes would reproduce potatoes that would have low or high solanine levels and the environments that would cause each type of evolution. Finally, research why solanne is harmful for humans to eat in high levels, as well as what "Blight" is and how solanine protects potatoes from it, and make sure to discuss any enzymes or proteins that are found in solanine.
Patrick Austin (email at paustin4@students.d125.org)
Potatoes consist of solanine, a “fat-soluble toxin” (Moalem 86), because solanine can protect potatoes from getting blight. Blight is a disease in which the potato is infected by a fungus-like organism that infects potatoes and renders potatoes inedible. Blight was responsible for the potato famine in Ireland in the 1840s and 1850s. Solanine protects potatoes from blight by blocking Phytophtora infestans, the organisms present in blight, from entering uncovered tubers at the surface of the potato. This often results in greenness and the spuds that we sometimes see.
ReplyDeletePotatoes with sufficient solanine have a selective advantage in that they will be able to better resist blight than potatoes that have an insufficient amount of solanine. This will then contribute to higher relative fitness for potatoes with abundant solanine, meaning that more patotoes with sufficient solanine will survive and also reproduce, providing sufficient solanine to their offspring. This relates with evolutional dogma that the ultimate goal of organisms is to survive and reproduce. Naturally, the Phytophtora infestans, the organism present in blight, are more prevalent in “moist, cool areas such as parts of North America, China, and Western Europe.” Therefore, there will be more potatoes with high levels of solanine in these moister and cooler areas in an effort to survive and reproduce, while there will be more proteins with lower levels of solanine in more dry and hotter areas where not as much Phyophtora infestans are present.
In humans, excess solanine in the body seems to affect mitochondria of cells and causes organs to fail. Symptoms are nausea, cramps, vomiting, and diarrhea. In some severe cases, potatoes that are green (an indication of very high solanine) can be lethal to humans.
Ken Saito (ksaito4@students.d125.org)
Sources:
http://www.wisegeek.com/what-is-potato-blight.htm
http://www.sciencebasedmedicine.org/index.php/killer-tomatoes-and-poisonous-potatoes/
Shttp://www.wisegeek.com/what-is-solanine.htm
Survival of the Sickest
Blight is a disease that infects the leaves, stems, and tubers (the part that humans eat) of potatoes. Some symptoms include dark, sunken areas on the surface of tubers and leaves as well as a wet, vile smell of rotting. The fungus-like organism called phytophthora infestans is responsible for blight. (http://www.gardenorganic.org.uk/factsheets/dc17.php) Potatoes produce solanine, a “fat-soluble toxin” (Moalem 86) in order to combat blight. The toxin solanine consists of carbons, hydrogens, and nitrogen oxides. (http://www.foodsafetywatch.com/public/154.cfm)
ReplyDeleteThrough an evolutionary lens, potatoes will adjust accordingly to the present environment that they live in to achieve the ultimate goal of surviving and reproducing. Therefore, in an environment where concentration of phytophtora infestans is high (often associated with warm temperatures), potatoes will adjust by producing solanine excessively. Conversely, potatoes will not feel the necessity to produce as much solanine in an environment in which concentration of phytophtora infestans is low (cooler temperatures). Especially for cases in which there is an abundance of phytophthora infestans, the production of more solanine functions as a selective advantage for the potato because these potatoes are more likely to survive and produce, contributing to a higher relative fitness. (Campbell 479-480). As a result, more and more offspring that produce a lot of solanine will be added to the gene pool of the next generation. The idea that different environmental conditions forces its inhabitants to adjust and, over time, evolve into new kinds of potato relates with Big Idea 1, which states that the process of evolution drives the diversity and unity of life.
As for the effect of solanine on humans, abundant consumption of solanine through potato-based foods such as french fries comes with detrimental effects. Common symptoms include gastrointestinal disturbances, vomiting, and diarrhea. In worse cases, neurological disorders can result. This can occur because solanine is a cholinesterase inhibitor that can impair neural function. (The ending “ase” suggests that solanine is an enzyme). Solanine can inhibit acetylcholinesterase, and as a result, acetylcholine accumulates. Acetylcholine is responsible for the neurological symptoms of symptoms, so neurological disorders are worse the more acetylcholine is abundant. In the worst case, excess solanine consumption can cause death. (http://www.safespectrum.com/articles/potato-toxicity-solanine.php)
-Ken Saito (ksaito4@students.d125.org)