Scientists Explain the Mechanism of Plant's Constant Growth

A research team from the University of Freiburg in Germany led by Prof. Dr. Thomas Laux has succeeded in confirming that plants need a micro-RNA at the tip of their shoots to prevent all of the stem cells from transforming themselves into other cell types. The Freiburg researchers used thale cress (Arabidopsis) as a model organism for their studies. Micro-RNAs are very small molecules of ribonucleic acid (RNA) that do not encode any proteins themselves but rather prevent proteins from being generated from other RNAs.

Scientists are already familiar with one micro-RNA that informs meristem cells that they should specialize. However, this micro-RNA needs to be neutralized in the area where stem cells need to be preserved. The research team was able to identify the second micro-RNA that serves precisely this function, thus preventing the stem cells from transforming.

The newly discovered micro-RNA, the stem cell preserver, is only produced in one particular cell layer, the epidermis of the tip of the shoot. The micro-RNA only reaches several underlying layers of cells near its home in the epidermis, all of which become stem cells. The more distant areas do not receive enough stem cell preservers, and the cells there transform themselves into other cell types. In this way, the plant can preserve the stem cells at the tip of its shoots and thus develop leaves, blossoms, or fruits regardless of environmental influences.

View the University of Freiburg's news release at http://www.pr.uni-freiburg.de/pm/2013/pm.2013-01-21.16-en?set_language=en.