While scientists have made major advancements in photosynthetic research over the last century, we still have a somewhat incomplete picture of the whole process. Slackers! Scientists would like to get a better idea of how photosynthesis is regulated. For example, we would like to know (yes, we at Shmoop would like to know) how an organism might change its light-harvesting abilities based on what is happening in its environment. Furthermore, while we have gained snapshots into the protein complexes that mediate photosynthesis, we would like to be able to watch photosynthesis happen on a microscopic level. Live. Advancements in microscopy techniques are beginning to make some of these wild and crazy dreams a distinct possibility.
Besides being a cool biological process, scientists study photosynthesis for two important reasons. For one, Photosystem I is considered to be the most efficient light-driven, energy-creating machine in Nature. One thing that you have probably learned from the oil industry is that energy = $$$...$...$. Many scientists are trying to either artificially mimic photosynthesis to generate energy or are trying to exploit photosynthetic organisms as energy producers.
How can scientists exploit photosynthetic organisms to generate compounds that we can use as fuel? One big step has been the sequencing of genomes (sets of encoded genetic information) of many photosynthetic organisms. These sequenced genomes allow scientists to more easily compare the different photosynthetic machinery in different organisms. Furthermore, knowing the sequence makes it easier when they try to modify the genomes of these organisms.
Why would scientists want to modify the genomes of organisms that have evolved over millions of years to perfect photosynthesis? Because, they are crazy and crave massive failure. Just kidding. The reason is that, while these organisms have evolved to better fit into their own environments, these evolved traits are not necessarily the best traits for generating fuel for humans. It's always about us, isn't it? Scientists can look for mutants that have useful changes in particular photosynthetic pathways, or they can try to create changes themselves by a wide variety of molecular and genetic techniques. In one instance, scientists have been able to generate mutants in the algae C. reinhardtii that have a defect in electron transfer around Photosystem I.11 The result is an increased production of hydrogen gas (H2), a clean and efficient energy source. Other mutants have been identified that increase the amount of carbon stored either as lipids or carbohydrates.
Scientists are also trying to artificially mimic photosynthesis: they use the Sun’s energy and water to produce usable energy.12,13,14 Currently, plants are still better (go plants!), but that may change in the coming years. Daniel Nocera, a professor at MIT and founder of the company Sun Catalytix, envisions a future where every house will have an artificial photosynthesis generator.
The result? He compares it to the change brought about when the automobile replaced horse-drawn transportation. According to an interview in Scientific American, Nocera said that, "…in 1898, concerned civic leaders from around the world gathered because estimates predicted that London would be buried under three meters of manure at the current rates of growth; New York City would have piles reaching to the third story of buildings. Within two decades, the problem was entirely gone. They didn’t see the automobile industry coming," said Nocera, "Shift happens."15
Current research on photosynthesis has the potential to substantially change the way that we as humans live. Imagine a world where cheap and efficient energy was the standard for everyone. Cheap fuel would sure make road trips (or even flying!) more affordable. The possibilities are endless…if only it would help you buy your own set of wheels!