It is scientifically proven that humans pass down their trauma and other DNA-specific changes from generation to generation. Otherwise known as epigenetic inheritance, several studies describe how DNA without structural change undergoes modifications, muting some genes in the offspring. Such a phenomenon is also noticed among plants where the species pass down epigenetic memories, helping the next generation to adapt better and live longer.
How Does Passing Epigenetic Memories Benefit The Plants?
While humans can build new houses or change their food and clothing, animals can move away from places. Plants continue to live long in the same place. Even if they are living beings, a plant can’t shift to a new land and start fresh altogether. Until someone decides to experiment with their growth. According to researchers, plants deal with more environmental stressors than other animals. For example, as the winters are becoming shorter in response to climate change, plants are altering their environmental clock to define flowering time. The situation continues to prevail among the next generation, getting themed in their epigenetic memories.
Species with epigenetic memories find it easy to continue with the changing environment. The plants pass down chemical tags or structural changes without customizing the genome base. The only difference is the change in “how genes are expressed.”
Methylation And Plants Passing Down Epigenetic Memories
Researchers from Howard Hughes Medical Institute & Cold Spring Harbor Laboratory came up with a study where they were keen to find out how plants pass down epigenetic memories. The focus was discovering markers that adequately inactivate transposons, or “jumping genes.”
When active, transposons can move around and disrupt the regular functionality of other genes within a cell. Plants use the methylation process to keep them quiet and protect the other cells. The result of this process adds regulatory markers to particular DNA sites, marking where the transposons are jumping around. During the methylation process, the DDM1 protein (which can silence jumping genes) clears the pathway for other important enzymes into the plant’s new DNA strands. The discovery of DDM1 protein dates back to 30 years ago. The initial finding was based on the plant thale cress or Arabidopsis thaliana.
Methylation And DDM1 Protein
You might be wondering why plant cells need DDM1 to clear the paths. That is because, in general, the plant DNA is very tightly packed. The cells wrap their DNA around packing proteins known as histones to keep it condensed. However, studies have also revealed that the histones must be slid out of the way before the methylation process. Otherwise, it will block access to other important enzymes.
The DDM1 protein is in charge of sliding DNA along with packing proteins. They are responsible for highlighting the essential sites in the plant that require methylation. Researchers say the process is like a yo-yo moving up and down the string. The histones do move through the DNA (up & down) and expose part of it at a time, but never fall off.
Also, further into the study, co-authors did use the process of cryo-electron microscopy. With the same, they used the process to capture detailed images of the enzymes interacting with the DNA & related proteins. According to the team, the DDM1 protein grabs specific histones and rearranges the packed DNA. The DDM1’s love for certain histones preserves the epigenetic memories for multiple generations.
The available knowledge prevents the next generation of plants from jumpy transposons that can disturb the entire genome. Further, the research team suggested that humans also have proteins that are the same as DDM1. Unlocking a huge potential for future research.