Exploiting a genetic quirk in potatoes may cut fertilizer needs

 Potatoes are one of the top three food consumed worldwide. Modern potatoes to be farmed and harvest require a large amount of nitrogen which can be provided under the form of nitrate fertilizer. Unfortunately nitrate fertilizers can be very high cost and cause harm to the environment. Potatoes are native of South America from the Andes region (Chile). Originally, the tubers grew only during winter to store nutrients, regulating itself with  the daylight of the winter season. In fact, tuber formation is an adaptive strategy of potato plants for winter survival. Shorter day and cooler temperatures are perceived by the plant for the change of the season, promoting formation of the tuber. When the plant was introduced in Europe in the 16th century it had to adapt to shorter amount of daylight and more rigid temperature. The occurrence of a natural genetic mutation in the gene StCDF1, helped the potato plant to adapt to the climate and to grow. StCDF1 regulates the growth of the tuber and in general of the plant. 

A group of researchers discovered that the same genetic mechanism that initiate the growth of the flower( StCDF1) and of the tuber is also what controls the nitrogen uptake of the plant. The gene as mentioned before regulates the daylight cycle and it work basically like a switch and can apparently switch on and off  the genes that control the nitrogen absorption. StCDF1 shuts off the production of nitrate reductase an enzyme that breaks down nitrate molecules so that the plant can absorb them. This discovery showed how this natural selection allowed potatoes plant to grow their tuber but make them more fertilizer-hungry.  The researchers disabled the gene to see if would affect nitrogen uptake and plant potatoes in a low nitrogen environment. The plant lacking the gene grew bigger and healthier than the other with the gene but didn’t create a tuber. The finding opens the door to developing a more nitrogen efficient potato variety of plant. Researcher are planning to continue to work on by using gene-editing techniques to make sure that the gene that produce the nitrate reductase enzyme doesn’t get controlled and repressed by StCDF1. Moreover, the researchers are also trying to achieve the same goal in a more traditional way by crossing farm potatoes with wild types that have altered nitrate reductase genes. 

This incredible finding could lead to develop a potato plant variety that could need less fertilizer, making it less expensive to cultivate and less harmful to the environment.