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

Genetically Modifying Plants for Efficient Food Production

Agricultural scientists at the University of Illinois have modified plant genes by allowing them to use sunlight more efficiently. Dr. Stephen P. Long, the lead author of the study, is a professor of crop sciences at the University of Illinois, and is a leading figure in crop science/photosynthesis research. Dr. Long and his team of scientists used genetic engineering techniques to alter photosynthesis in tobacco plants. Their study, published by the journal Science, found a 20% increase in biomass compared to wild-type plants grown in the same field environment. They used tobacco because it is easy to manipulate when trying new genetic alterations, and they hope food crops will also be as successful.

Check out the Science Magazine video on Youtube!

The point of the study was to improve a plant’s recovery time from photoprotection after light stress.  It allows for a plant to release some of that absorbed energy as heat so that they can efficiently use the carbon dioxide available from their environment. Think of it as photosynthesis on steroids, and photosynthesis is how plants convert sunlight, carbon dioxide and water into new, energy-rich carbohydrates, also known as a majority of our food sources. Dr. Long has long argued that the process is inefficient because it uses less than one percent of the energy that’s available to them. His team of scientists were able to increase leaf growth between 14 and 20 percent by genetically modifying part of a plant's protective system that is activated when in the presence of excessive sunlight. Generally, plants don’t take the optimal amount of energy available to them, and it takes ten minutes to an hour for a plant to adjust its protective system.  Dr. Long and his team have genetically modified the plant to turn that protection system off and on faster.

"Now that we know it works, it won't be too difficult to do it with other crops," said Dr. Long, a professor of crop sciences at the University of Illinois. "If you look at crops around the world, it would (increase yield) many million tons of food.” 

“A plant's protective system is like a pressure relief valve in a steam engine. When there's too much sunlight, it turns on and gets rid of excess energy safely. When the plant is in the shade, the protective system turns off, but not quickly, said study co-author Krishna Niyogi, a plant scientist at the Howard Hughes Medical Institute and the University of California, Berkeley.

This is the first time scientists have been able to do something like this, and it is an amazing step towards solving world hunger.  Hopefully the public's collective fear of GMO’s won't keep this breakthrough from being utilized. All the awesome science in the world can be crippled by the rejection of consumers.  The breakthrough could eventually dramatically increase the amount of food that can be grown in the world. The Bill and Melinda Gates Foundation are in support of this technology and they hope it might help alleviate global poverty.

It can also be argued that plants don’t have a “glitch” that needs fixing, and that people shouldn't fix what’s not broken. Speeding up a naturally occurring process can be considered to be detrimental towards progress.  When you haste, you waste. The conservative approach may indeed be best for a plant’s offspring, but what is best for the plant is not the same as is what is best for the farmer.