Must be in a science-article mood this weekend

“Billion-year Upgrade”

Bob Holmes

New Scientist

2/19/2011, p42-49

                Bob Holmes’ article discussed how to make photosynthesis more efficient in crop plants. Basically, the act of photosynthesis started billions of years ago in cyanobacterium. While their photosynthetic process is constantly involving, the one in plants is not as much because of the slow growth rate and ever-changing structure of plants. The fault in plants is that the enzyme rubisco first developed in a time on the earth when oxygen was not present. During this time, rubisco had no problem changing carbon dioxide into carbons for the Calvin cycle. But now, since oxygen is so prevalent, the carbon dioxide and oxygen seems almost interchangeable for rubisco, and when oxygen is used, the cell destroys food instead of making it. In order to cut down on this, scientists suggest we take a hint from cyanobacterium and genetically create crops that have carboxysomes (little internal pockets that surround rubisco and only have bicarbonate pumped in, which carbon anhydrase makes into carbon dioxide before it enters rubisco). There are skeptics who suggest that since the plant hasn’t made this evolutionary change by itself, maybe it can’t physically do it, but scientists believe that it is possible. Another type of change that scientists are trying to adapt in plants is that of nitrogen-fixation. Since plants need nitrogen to make proteins, they need a more direct way than just taking it from the soil using their roots. By putting the genes into the plants chloroplast, they believe that the plant won’t reject them (since it is “essentially putting bacterial genes in a bacterial system”).  The problem is that the key enzyme in this process is rendered useless by oxygen, which is a product of photosynthesis, done in chloroplasts. The possible solution is putting the process on a “molecular timer”, making the nitrogen fixation happen during the night and the photosynthesis happen during the day, when the enzyme is inactive. Both of these genetic alteration plans are underway and hope to be successful in about three years.

               

This information is important because of the rising price of food. Everywhere you turn the price of food is slowly rising because of the fact that we have more people than ever to try to feed on the Earth. The less of a food that is available and the higher the demand, the more the food companies can charge for said food, making it very expensive to survive. And when a tropical storm hits (which seems to frequent as of late), the entire agricultural output is destroyed in that area, putting more stress on the food market. Having a better crop, a crop that can photosynthesize more efficiently, would really help make sure that we always have enough food to maintain a balance in prices and effectively feed everyone. This is because the crops will yield more, as there will be more of them and they will be larger in size. The article said using this old and outdated version of photosynthesis and trying to make the demands for food is “like building a modern aircraft carrier and powering it with a Victorian steam engine”. In a day and age that places such an emphasis on developing our technology and resources, we should place time and effort on developing something that people cannot live without: food.

I believe that people who plan on being part of the agricultural science and market field should read this article. Some may not realize that to better our plants’ yield, we may actually have to alter the plant itself, not just its growing conditions. This seems to be an up and coming scientific goal, and the payoff of the things suggested in the article could lead to an increase in food yield of 15%. That is a huge number when we are talking of a lot of plants. I found this article easy to read, so it would be a great introduction into this topic for those interested.
Sincerely Sydney