In potato plants, researchers have made important breakthroughs to determine mutation rates in stem cells. With this exciting new knowledge comes the ability to imagine how these mutations might be used to improve plant reproduction and growth. The research was just published in the journal Proceedings of the National Academy of Sciences (PNAS). It looks closely at two potato varieties, Desiree and Red Polenta, which researchers have clonally propagated for upwards of 50 years. This discovery uncovers the role of apical meristem as a key driver of DNA mutagenesis in these plants. This region of three layers of stem cells encapsulates its importance in plant development.
The apical meristem consists of approximately ten stem cells arranged in three distinct layers: L1, L2, and L3. Layers of meristematic cells in each section are active zones of creation and invention of new plant tissues. By isolating individual stem cells from each layer, the researchers were able to compare the mutation rates and found significant differences among them. What was most surprising about the study was that L1 cells in Desiree potatoes accrued 4.5 times as many mutations than did L2 cells. In line with this, Red Polenta potatoes demonstrated that L1 cells had an increase of 1.6 times more mutations than L2 cells.
One of the most surprising things that this research found. It revealed that the L3 layer was completely lacking in the apical meristems of the plants’ leaves. As you can see, this layer has been invaded and replaced by L2 cells. This brings into question the robustness and operability of the full apical meristem. This layer’s lack, though, highlights the need for more research into how these amendments to the environment might impact plant growth.
The scientists underscored that plants have the ability to reproduce clonally or vegetatively. Consequently, such plants harbor and transmit mutations from all three tiers of stem cells. Their experimental crossing involved growing cloned cells in isolation to generate plants developed entirely from L1, L2, or L3 cells. Their cutting-edge method made it possible to track the rate at which DNA mutations built up over time in different types of stem cells.
Luca Comai, the Kenneth Fritsch distinguished professor of plant biology, served as the study’s senior author. He noted that these discoveries are fundamental for understanding how plants adapt to their environment and maintain homeostasis. The study reveals how DNA mutations accumulate within the stem cells that produce a plant’s outer covering. Surprisingly, these mutations are 4.5 times more frequent than in the stem cells that create our eggs and sperm. This notable difference raises important questions about the effects of TE activity for plant breeding, as well as genomic stability.
The study’s findings helps fill this gap with a deeper understanding of evolutionary dynamics in plants and their ability to adapt. As researchers increasingly dig into these complexities, they could discover additional implications for agricultural practices and crop advancement.