Dr. Portis, let's start with you. Could you define your area of research and how it impacts on some of the goals of ARS?

Dr. Archie Portis -- I work on the enzyme rubisco and the protein that regulates it. Rubisco is a protein that initially captures atmospheric carbon dioxide (CO₂) and starts the whole photosynthetic system on its way. There has been a long-standing interest in rubisco because it's not a very efficient enzyme -- plants invest about 30 to 40 percent of their total soluble protein to make this one protein. In addition to its sluggish catalytic rate, the other problem is that rubisco doesn't only capture CO₂, it also captures oxygen (O₂) in what is called an oxygenase reaction. The oxygenase reaction essentially reduces potential plant productivity by about 30 percent. If we can understand the oxygenase reaction so that we can reduce it, or otherwise improve rubisco efficiency, then we can increase potential plant productivity.

Are you trying to manipulate this protein? What is the focus of the research going on in your lab?

Portis -- For the most part, we've been trying to understand how plants regulate rubisco activity. We know that they do regulate it, but we don't understand why or exactly how. Why don't plants maintain maximal activity of this protein all the time? But just recently we've also begun trying to manipulate rubisco. Some rubisco proteins in nature have different catalytic potentials and basically limit rubisco's ability to carry out its oxygenase reaction. We are taking one of these natural proteins and introducing it into soybeans to see if we can improve plant productivity.

So on one level you're doing very fundamental research, trying to find out the mechanisms for why the plants don't work at peak efficiency all the time. Then, on another level, you're working on concrete benefits of this research, trying to increase plant productivity by introducing these other proteins, right?

Portis -- Right. We're trying to genetically transform soybeans. We're trying to work out the procedure and methods required to transform the chloroplast in soybeans, which hasn't been done before. Of course, this information will be useful even if the protein we introduce doesn't work more efficiently. When researchers do determine how to modify rubisco effectively, the road map showing how to introduce these modified proteins into soybeans will already be there.

Ort -- Another of our interests in rubisco is its potential for taking advantage of increased atmospheric CO₂ concentrations. The higher CO₂ levels go, the greater the probability that rubisco fixes CO₂ instead of O₂. However, although photosynthetic efficiency does go up at elevated CO₂ levels, in a matter of days, weeks, or months, the plant no longer "takes advantage" of the elevated CO₂. It's one of the issues that pervades research at the PRU. First we'd like to understand this acclimation to increased CO₂ concentrations and then do something about it. The potential of plants to accomplish more photosynthesis at higher CO₂ concentrations is one of the few bright spots associated with what humans are doing to the atmosphere, but it looks like very few plants can truly take advantage of it.