Friday, December 2, 2016

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.

tobacco leaves
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.



  1. I believe genetic engineering gets a pretty bad reputation among the general public. This is a good way to showcase some of the benefits that can come from genetic engineering, as it used to increase food production.

  2. In our changing climate and ever rising population, we have a few (dwindling) options when it comes to food production. For one, we can go up not out and vertically farm so as to use less land. The more complex option is to increase yields by altering photosynthetic processes, I'm pretty amazed by this research to have managed this feat. Thanks to genetic engineering we're more and more likely to be able to sustain ourselves decades to come.