Nav: Home

How plants forget

May 13, 2020

Although they do it differently than humans, plants also have memories. For example, many plants can sense and remember prolonged cold in the Winter to ensure they flower at the right time during the Spring. This so-called "epigenetic memory" occurs by modifying specialized proteins called histones, which are important for packaging and indexing DNA in the cell. One such histone modification, called H3K27me3, tends to mark genes that are turned off. In the case of flowering, cold conditions cause H3K27me3 to accumulate at genes that control flowering. Previous work from the Berger lab has shown how H3K27me3 is faithfully transmitted from cell to cell so that in the Spring, plants will remember that it was cold and that winter is over, allowing them to flower at the right time. But just as importantly, once they've flowered and made seeds, the seeds need to forget this 'memory' of the cold so that they do not flower too soon once winter comes around again. Since H3K27me3 is faithfully copied from cell to cell, how do plants go about forgetting this memory in seeds?

To answer this question, an international team lead by Dr. Michael Borg, a postdoc in the lab of Dr. Frédéric Berger at the Gregor Mendel Institute of the Austrian Academy of Sciences, set out to analyse histones in pollen, hypothesizing that the process of forgetting would most likely occur in the embedded sperm. The researchers were surprised to find that H3K27me3 completely disappeared in sperm. They found that sperm accumulate a special histone that is unable to carry H3K27me3. This ensures that this modification is erased from hundreds of genes, not only those that prevent flowering but also ones which control a large array of important functions in seeds, which are produced once the sperm is carried by the pollen to fuse with the plant egg cell. This phenomenon is called "epigenetic resetting" and is akin to erasing and reformatting data on a hard drive.

"This actually makes a lot of sense from an ecological perspective" says Dr. Borg. "Since pollen can spread over long distances, by wind or bees for example, and much of the "memory" carried by H3K27me3 is related to environmental adaptation, it makes sense that seeds should "forget" their dad's environment and instead remember their mother's, since they are most likely to spread and grow next to mom."

According to Dr. Berger "Like plants, animals also erase this epigenetic memory in sperm, but they do it by replacing histones with a completely different protein. This is one of the first examples of how a specialized histone variant can help reprogram and reset a single epigenetic mark while leaving others untouched. There are many more unstudied histone variants in both plants and animals, and we expect that aspects of this resetting mechanism we have discovered will be found in other organisms and developmental contexts."
-end-
This work was carried out by an international team with members from the Gregor Mendel Institute in Austria, the Cold Spring Harbor Laboratory, Yale University, University of Kentucky, and Purdue University in the USA, Nagoya University in Japan, University of Edinburg in the UK, and the Instituto.

Gulbenkian Ciência in Portugal. Funding was provided by the Austrian Science Fund, ERA-CAPS, the Howard Hughes Medical Institute, NIH, the Japan Society for the Promotion of Science, the Wellcome Trust, and the European Research Council.

Borg M, Jacob Y, Susaki D, et al. (2020) Targeted reprogramming of H3K27me3 resets epigenetic memory in plant paternal chromatin. Nature Cell Biology. https://www.nature.com/articles/s41556-020-0515-y

For more information, please contact: Matt Watson matthew.watson@gmi.oeaw.ac.at +43 1 79044 9101

About the GMI The Gregor Mendel Institute of Molecular Plant Biology (GMI) was founded by the Austrian Academy of Sciences in 2000 to promote research excellence in plant molecular biology. It is the only international center dedicated to basic plant research in Austria and one of very few throughout the world. Nine research groups study many aspects of plant molecular genetics, including epigenetics, cell biology, plant-pathogen interactions, developmental biology, and population genetics. The GMI is part of the Vienna BioCenter, one of Europe's foremost life science research locations.

Gregor Mendel Institute of Molecular Plant Biology

Related Memory Articles:

Memory protein
When UC Santa Barbara materials scientist Omar Saleh and graduate student Ian Morgan sought to understand the mechanical behaviors of disordered proteins in the lab, they expected that after being stretched, one particular model protein would snap back instantaneously, like a rubber band.
Previously claimed memory boosting font 'Sans Forgetica' does not actually boost memory
It was previously claimed that the font Sans Forgetica could enhance people's memory for information, however researchers from the University of Warwick and the University of Waikato, New Zealand, have found after carrying out numerous experiments that the font does not enhance memory.
Memory boost with just one look
HRL Laboratories, LLC, researchers have published results showing that targeted transcranial electrical stimulation during slow-wave sleep can improve metamemories of specific episodes by 20% after only one viewing of the episode, compared to controls.
VR is not suited to visual memory?!
Toyohashi university of technology researcher and a research team at Tokyo Denki University have found that virtual reality (VR) may interfere with visual memory.
The genetic signature of memory
Despite their importance in memory, the human cortex and subcortex display a distinct collection of 'gene signatures.' The work recently published in eNeuro increases our understanding of how the brain creates memories and identifies potential genes for further investigation.
How long does memory last? For shape memory alloys, the longer the better
Scientists captured live action details of the phase transitions of shape memory alloys, giving them a better idea how to improve their properties for applications.
A NEAT discovery about memory
UAB researchers say over expression of NEAT1, an noncoding RNA, appears to diminish the ability of older brains to form memories.
Molecular memory can be used to increase the memory capacity of hard disks
Researchers at the University of Jyväskylä have taken part in an international British-Finnish-Chinese collaboration where the first molecule capable of remembering the direction of a magnetic above liquid nitrogen temperatures has been prepared and characterized.
Memory transferred between snails
Memories can be transferred between organisms by extracting ribonucleic acid (RNA) from a trained animal and injecting it into an untrained animal, as demonstrated in a study of sea snails published in eNeuro.
An immunological memory in the brain
Inflammatory reactions can change the brain's immune cells in the long term -- meaning that these cells have an 'immunological memory.' This memory may influence the progression of neurological disorders that occur later in life, and is therefore a previously unknown factor that could influence the severity of these diseases.
More Memory News and Memory Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Debbie Millman: Designing Our Lives
From prehistoric cave art to today's social media feeds, to design is to be human. This hour, designer Debbie Millman guides us through a world made and remade–and helps us design our own paths.
Now Playing: Science for the People

#574 State of the Heart
This week we focus on heart disease, heart failure, what blood pressure is and why it's bad when it's high. Host Rachelle Saunders talks with physician, clinical researcher, and writer Haider Warraich about his book "State of the Heart: Exploring the History, Science, and Future of Cardiac Disease" and the ails of our hearts.
Now Playing: Radiolab

Insomnia Line
Coronasomnia is a not-so-surprising side-effect of the global pandemic. More and more of us are having trouble falling asleep. We wanted to find a way to get inside that nighttime world, to see why people are awake and what they are thinking about. So what'd Radiolab decide to do?  Open up the phone lines and talk to you. We created an insomnia hotline and on this week's experimental episode, we stayed up all night, taking hundreds of calls, spilling secrets, and at long last, watching the sunrise peek through.   This episode was produced by Lulu Miller with Rachael Cusick, Tracie Hunte, Tobin Low, Sarah Qari, Molly Webster, Pat Walters, Shima Oliaee, and Jonny Moens. Want more Radiolab in your life? Sign up for our newsletter! We share our latest favorites: articles, tv shows, funny Youtube videos, chocolate chip cookie recipes, and more. Support Radiolab by becoming a member today at Radiolab.org/donate.