Scientists Modify Plants to Improve Photosynthesis

Photosynthesis is the process in which plants convert light energy, carbon dioxide, and water into glucose and oxygen. According to scientists, it's an inefficient process which uses less than 1% of the energy available. This is because plants have a protective system (Photoprotection) in their leaves, which turns on if there is too much sunlight and prevents the plant from absorbing any more light energy until there is shade from a cloud or anything else that covers the leaf. How this works is that enzymes in the leaf create a surge of a paprika-colored called zeaxanthin, which helps in getting rid of the excess energy as heat. The problem with this process is that even in the shade, the protection system takes a long time to turn off, which costs up to 20% of the plant's potential yield. A group of scientists modified three genes in tobacco plants which altered the photoprotection mechanism in their leaves to enhance photosynthesis.


The blue and purple spots show where tobacco leaves waste energy by partially shutting down in response to bright light. The red and yellow spots show where the leaves are running closer to full capacity.


The research team modified the ZEP enzyme,which functions to dismantle the protective system.  The problem with only enhancing ZEP production in the plant is that it can disrupt the initiation of the protective system, which could cause the plant to take in too much sunlight and harm itself. So the research team also enhanced an enzyme called VDE which builds the zeaxanthin, to create a good balance between the two processes. The scientists also enhanced a third protein PsbS, which also helped, although the scientists aren't certain how it did. The results were that the tobacco plants with all three of the modified proteins grew bigger than those without the modified proteins. This confirmed that the photosynthetic process was enhanced. 

The protective system in the tobacco plant is also in other many important crop plants such as rice. Therefore, this is an important economic gain because it can help in meeting global food demands to keep up with the growing global population. I believe that this is a great example of how genetic engineering can be very beneficial. I never thought that this would be a pro to genetic engineering and I hope to learn about other important pros.


    
Links:
https://www.sciencenews.org/article/tweaking-how-plants-manage-crisis-boosts-photosynthesis

http://science.sciencemag.org/content/354/6314/857.full

Cancer mutation patters differ in smokers/non-smokers

An international team of researchers found several differences in the amount of altered DNA signatures in the tumors of smokers compared with those from non-smokers with the same type of cancer.

"Tobacco smoking leaves permanent mutations - it erodes the genetic material of most cells in your body", says Ludmil Alexandrov of Los Alamos National Laboratory in New Mexico, who led the analysis. "Even if you are just a social smoker who occasionally has one or two or five cigarettes, there is a cumulative effect."

The team compiled data on over 5000 human samples of 17 different cancers. The DNA was then searched for patterns of damage, known as "mutation signatures". One type of mutation, called "Signature 4", which indicates damage to Guanine, showed a far greater presence in tissues exposed to tobacco smoke. Signature 4 also strongly correlated with lung squamous cancer, lung adenocarcinoma and larynx cancers.

Strangely, signature 4 showed a significantly lesser correlation with oral, pharynx, and esophagus cancer, despite being just as exposed to tobacco smoke as the lungs and larynx. Researchers also were able to graph the relationship between quantity smoked and number of mutations. For instance, a pack a day for one year leads to 150 mutations in a lung cell, 97 in a larynx cell, 39 in the pharynx, 23 in the oral cavity, 18 in the bladder and 6 in the liver cell.

I take interest in the genetic or hereditary aspects of tobacco resistance. I have known individuals who have smoked a pack or so a day for numerous decades and never got lung cancer, and others who have smoked far less over a shorter period of time, yet fell ill with some respiratory related cancer.

Genetic Modifications to Tobacco May Result in a Solution to World Hunger

Ten years ago, scientists at the University of Illinois thought of the idea to alleviate world hunger by tinkering with photosynthesis in crops. Funded by the Bill and Melinda Gates Foundation, they have made significant progress. Working with tobacco as the test crop, the scientists were able to increase productivity by 20 percent. This is an incredible number considering other agricultural methods only result in a 1 or 2 percent increase. When plants receive excessive sunlight, they activate a mechanism that sheds the extra energy off as heat. The genes that are introduced are to minimize the amount of time the mechanism takes so that the plants can get back to carbohydrate production more quickly.

The scientists and the foundation have no interest in increasing the productivity of tobacco, but it is a fast and easy plant to genetically alter, making it ideal. The plan is to begin doing the same alterations on food crops. They think that crop yields can be improved by certain genetic changes. The head scientist on the work claims that, if all goes well, productivity increases of 50 percent may eventually be achievable. This would completely change the face of the agricultural world. Global hunger would virtually vanish. If this experiment is a success, genetically modified organisms would undoubtedly be essential, squashing the debate over whether or not it is just. This research has not yet proved that the international food supply could increase. The scientists still have a long way to go towards proving their goal, but the work is very promising.

As the global population continues to grow, world hunger is becoming an increasingly troublesome issue. Scientists are testing all sorts of ideas to solve this problem. This study is one of the more intriguing experiments that I have come across. Genetically modified organisms have already proved to be useful in the agriculture industry. If the scientists of this work are able to deliver the same results in food crops, the solution to world hunger may be taking a massive step forward.

Scientists see promise in genetic tinkering of plants

Last decade, agricultural scientists at the University of Illinois suggested tinkering with genes responsible for photosynthesis in plants  in order to increase yield. Despite original skepticism, the project has now been receiving funding for several years by the Bill and Melinda Gates foundation.

Results have been remarkable; using genetic engineering techniques on tobacco, productivity has increased by as much as 20%, as described in a study published by Science journal. The significance of this percentage is evident by the fact that conventional methods used by plant breeders increase gains by only 1-2%.

One of the lead researchers of the project believes production gains of 50% may be possible. Another lead researcher, Dr. Stephen Long, believes that should such production gains actually come to fruition, it would ultimately lead to a "second green revolution". Named after the original green revolution of the 1960's and 1970's which transferred advanced agricultural techniques to developing countries.

Though the New York Times article states that these new advances in crop engineering will work to combat "world hunger" in impoverished regions, I am skeptical as to what this term actually means in the current year. By all accounts, population is exploding in regions with the lowest HDI values, while countries with the highest HDI values see stagnant or decreasing population. For instance, Niger, which is currently at the bottom of the HDI list (ranked 188th), has an average fertility rate of 7.6 children per woman. At current projections, the total population of Niger will triple by the year 2050, and this is without a "second green revolution". Perhaps it is important to first get population growth under control and focus on increasing standard of living per individual, before introducing technologies which, if left unchecked, will lead to immense and unsustainable population growth, until the next "green revolution" is necessary.

Photosynthesis Will Save the World!

About a decade ago researchers at the University of Illinois suggested that editing the photosynthetic process in plants, could help to increase the plants yield.  This idea was approached with skepticism, but after years of research, a breakthrough has been made.  The model organism for this theory was tobacco.  It was injected with a portion of DNA form mouse-ear cress, a common lab plant, and after some time, some remarkable data was seen.  The edited tobacco strain was producing approximately 20% more yield than the standard plant.

Researchers have no use for increasing the yield of tobacco, but because it grows and fruits the same way as edible plants, it is planned to be used in these plants.  Due to the process, which involves speeding up the process of photosynthesis by turning off the plants "sunshield" faster.  Since plants get their energy form the sun, they need a mechanism to prevent the leaves from getting a form of sunburn.  That is where the sunshield comes in.  The only problem is that it stays on for too long after it is needed, and so the plant wastes time with that instead of carrying on with photosynthesis.  This edited tobacco strain simply turns off the sunshield much faster than the unedited plants, which ultimately lead to more photosynthesis, and more yield in the plant.

I think that this is a really ingenious way to increase plant productivity.  If this process works in the fruiting plants that we consume, this will lead to an extreme change and a whole new agricultural revolution.  This new production of plants can lead to solving hunger and poverty problems across the globe, and also help the global economy a little.  Overall, if this works out, we have some big news to look forward too.

http://www.nytimes.com/2016/11/18/science/gmo-foods-photosynthesis.html?rref=collection%2Fsectioncollection%2Fscience&_r=0 

http://www.sciencemag.org/news/2016/11/how-turning-plants-sunshield-can-grow-bigger-crops 

The Difference Between Cancer Mutation Patterns in Smokers and in Non-Smokers

     Gene mutations in any organism can have several causes. Smoking, however, has been known to increase the risk of around 17 cancers, including lung cancer, bladder cancer, kidney cancer, and many more. Tobacco smoke is a complex mixture of chemicals, at least 60 of which are carcinogens. A new analysis shows that DNA in cancerous tissues of smokers are different from those in cancerous tissues of non-smokers. Cancer geneticist Ludmil Alexandrov and his international research team conducted an experiment in which they analyzed and examined mutational signatures and DNA methylation in DNA extracted from 5000 genome sequences, half of which were from smokers. What showed the increase in cancer risks in smokers were the mutational signatures 2,4,5,13, and 16. 

    
  
     Signature 4 mutation signals damage to guanine and it appears in DNA of cells which were exposed to chemicals from burnt products, such as tar in cigarette smoke. This signature was found in non-smokers' tumors, but less often. Smokers with lung squamous cancer, lung adenocarcinoma and larynx cancers had high numbers of signature 4 mutations, while cancers of oral cavity, pharynx, and esophagus had much less signature 4 mutations. Even though the reason why these tissues didn't have as much signature 4 mutations, despite being the most directly exposed to smoke, is unclear, the team speculates that these tissues might metabolize smoke differently.

     Another difference observed between the smoker's damaged DNA and that of non-smokers was the presence of signature 5 mutations. This signature normally shows up in all cancer types but its cause is still unknown. However, it is known that it increases with age and the analysis revealed that the more a person smoked, the more signature 5 mutations were present. Smokers with lung adenocarcinoma also appeared to have more signature 2 and 13 than non-smokers with the same disease. These could have resulted from overactive DNA editing machinery. However they are found in many types cancer and it's still unclear how smoking influenced the increase in these signatures. Signature 16 has only been found in liver cancer tumors, but it was in a higher number in smokers' damaged DNA than in those of non-smokers. It's correlation to smoking is also unknown.

     The researchers took into account the pack years smoked (1 pack year = one pack of cigarettes per day per year) and found a positive correlation between pack years and the number of mutational signatures. This information helped them calculate the mutations caused by smoking for each cancer type in the tumors they researched. The results were that one pack year leads to 150 mutations in a lung cell, 97 in a larynx cell, 39 in the pharynx cell, 23 in the oral cavity cell, 18 in the bladder cell, and 6 in a liver cell.

     I think that this information is very important for the public, so that it can bring better awareness to how harmful smoking is and how important it is to help treat people with smoking addictions. I hope that more answers can be found about how the signatures mentioned in the previous paragraph cause cancer and what the correlation between these mutations and smoking is, because this information can also help identifying the causes of other cancers due to these mutations.

Links:

• https://www.sciencenews.org/article/cancer-mutation-patterns-differ-smokers-nonsmokers

• http://science.sciencemag.org/content/354/6312/618.full

Malaria Treatment From Tobacco Plants

 http://www.sciencephoto.com/image/259781/large/M2100408-Malaria_infected_red_blood_cell,_SEM-SPL.jpg

An article from Sciencedaily news, www.sciencedaily.com/releases/2016/10/161020142815.htm, stated that tobacco plants can be genetically modified to produce a compound that is very helpful against fighting malaria. The actual paper written by the scientists is titled, “Compartmentalized Metabolic Engineering for Artemisinin Biosynthesis and Effective Malaria Treatment by Oral Delivery of Plant Cells”, published in Molecular Plant in 2016. (http://www.cell.com/molecular-plant/abstract/S1674-2052(16)30222-2). Malaria is a mosquito-borne disease that is carried and transmitted by a parasite. The image above is a SEM of a malaria infected red blood cell. Artemisinin is the compound that can destroy the malaria parasite in the bloodstream within 48 hours. The reason it is not in use in the place that need it is because they do not have access the plant or the extraction methods used to get the artemisinin. Artemisinin comes from the plant Artemisia annua or more commonly known as sweet wormwood. Africa and southern Asia is where malaria is at its worst and sweet wormwood is not easy to grow in these types of climates. The ideal plant that could be genetically modified to produce artemisinin is one that would thrive in the climates where malaria is common. The extraction methods are also very costly making even more inaccessible for people in under-developed areas where malaria is ramped. Tobacco seemed to be a good fit because it does thrive in climates similar to that of Africa’s or Southern Asia, and it is easily genetically manipulated. Early studies, on the other hand, produced a low yield of the artemisinin. Shashi Kumar and her team did not give up on the tobacco plant, they used the tobacco plant and utilized a dual-transformation approach. This approach is basically just put the genes that code for artemisinin production in two different places, in the chloroplast and the again in the nuclear genome. This was proposed and later confirmed that the tobacco plants would produce more artemisinin and therefore be more effective in fighting malaria. They study also suggested that eat the whole plant is more effective than just injecting the pure artemisinin. This could be due the cell wall which is thought to hindering the enzymatic break down of the artemisinin, like a time release capsule. 

Cell Press. (2016, October 20). Tobacco plants engineered to manufacture high yields of malaria drug. ScienceDaily. Retrieved October 26, 2016 from www.sciencedaily.com/releases/2016/10/161020142815.htm

Karan Malhotra, Mayavan Subramaniyan, Khushboo Rawat, Md. Kalamuddin, M. Irfan Qureshi, Pawan Malhotra, Asif Mohmmed, Katrina Cornish, Henry Daniell, Shashi Kumar. Compartmentalized Metabolic Engineering for Artemisinin Biosynthesis and Effective Malaria Treatment by Oral Delivery of Plant Cells. Molecular Plant, 2016; DOI: 10.1016/j.molp.2016.09.013
http://www.cell.com/molecular-plant/abstract/S1674-2052(16)30222-2