PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

How new plant cell walls change their mechanical properties after cell division

Biomechanics reveals cell wall age properties and how newly born cells can change their local shape and influence the growth of plant organs

How new plant cell walls change their mechanical properties after cell division
2023-10-02
(Press-News.org) Scientists reveal new plant cell walls can have significantly different mechanical properties compared to surrounding parental cell walls, enabling cells to change their local shape and influence the growth of plant organs.

This is the first time that scientists have related mechanics to cell wall “age” and was only made possible through a new method that follows the same cells over time and through successive rounds of division.

The Cambridge researchers were able to see new walls forming and then measure their mechanical properties. This pioneering work showed that new cell walls in some plants are 1.5 times stiffer than the surrounding parental cell walls – an unexpected and surprising finding.

The size and shape of plant organs like leaves and flowers is the result of complex interactions between genetics, signalling, mechanical feedback, and environmental cues. While we have made a lot of progress in understanding these processes, it is not always easy to connect what happens at the cellular scale with what happens at the organ scale.

Research undertaken on two distantly related plant species at the Sainsbury Laboratory Cambridge University (SLCU) provides new evidence suggesting local level cell division has an active role to play in controlling organ size. The interdisciplinary project was a collaboration between three SLCU research teams (Robinson Group, Schornack Group and Jönsson Group) and the SLCU Microscopy Facilities Team, bringing together expertise in experimental biomechanics, genetics, imaging and computational modelling.

Combining advanced live microscopy imaging of individual cells, advanced material characterisation methods, and mathematical modelling, Sarah Robinson’s research group has revealed the process of cell division locally alters the mechanical properties of the growing tissue, which potentially impacts on the final shape and size of the plant organ. The findings were published in Proceedings of the National Academy of Sciences (PNAS) this week (6 October 2023).

Compared to animal cells, plant cells are enclosed by a rigid box – the cell wall. Cell division involves the addition of new cell walls, which alter the mechanical stress in the cell, its geometry and the mechanical properties of the surrounding tissue.

Scientists have been able to probe the mechanical properties of individual cell walls in the outer cell layer of a plant organ, but they did not know how old each wall is and could only guess if it had just divided. First author of the paper, former researcher in the Robinson Group and now a research fellow at Politecnico di Milano, Alessandra Bonfanti followed cells over time and could see new walls forming and therefore was able to relate mechanics to cell wall “age”.

Dr Bonfanti developed a protocol that combines time-course imaging with atomic force microscopy measurements (AFM) to systematically map the age, growth and mechanical properties (stiffness) of individual cells walls and to follow the same cell walls through successive rounds of division.

“We have known for some time that the cell wall is a highly dynamic material. New material is added during cell division, while cell wall mechanical properties are modulated during growth to allow walls to undergo significant changes in shape and size without breakage,” Dr Bonfanti said. “Yet, how the mechanical properties of new cell walls transiently change in space and time was still unknown until we developed a new protocol that allowed us to measure the mechanical properties of cell walls over time”.

“We used this protocol to address how the stiffness of newly formed cell walls varies at 24-hours and 48-hours up until its mature stage, and how this affects local cell shapes”, Dr Bonfanti said. “To do so we made use of two systems: gemmae of the liverwort Marchantia polymorpha, and the early-stage first true leaf of Arabidopsis thaliana”.

The cells in the young tissues of the two plant species studied initially have a similar square-shaped geometry, which made them good models to compare.

“We first characterised the growth and cell division pattern in M. polymorpha gemmae, which was still unclear in the literature”, said Dr Bonfanti. “Then, with the optomechanical measurements, using time course imaging combined with AFM measurements, we demonstrated that cell division in M. polymorpha gemmae results in the generation of a temporary stiffer and slower growing new wall. In contrast, this transient phenomenon is absent in A. thaliana leaves.”

In fact, the new cell walls in M. polymorpha became 1.5 times stiffer than the parental cell walls.

“We have shown that there are significant differences in the stiffness of new cells walls compared to parental walls and that these differences contribute to the cell’s geometry and growth,” Group Leader Dr Robinson said. “This suggests cell division and its varying mechanical properties alters the rate of tissue expansion and could impact final organ size.”

Dr Robinson explained the significance of the discovery: “We already knew that cell walls loosen and become softer when cells are growing as the walls must stretch so the cells can expand as they grow. But we didn’t know what would happen when a cell divides and what properties the resulting new cell wall would have. Would they be the same or different to the walls in the surrounding tissue and how this would this impact cell growth?

“The fact that the new cell walls are much stiffer results in organ growth being restricted as it impedes the growth and influences the shape of component cells.

“The M. polymorpha cells also change their geometry and develop a 120° junction angle quicker to form cell geometries closer to hexagonal shapes, which are thought to be the most efficient shapes in terms of forming a material to cover an area. The computational modelling done in this project by Euan Smithers and Ross Carter provided evidence that the presence of a stiff new wall accelerates the formation of these 120° angles.”

“It is important to know that the new cell wall can be different to the parental wall and this gives us new questions to explore – is that always the case, in what conditions, and why is this the case?”

 

Reference

Alessandra Bonfanti, Euan Thomas Smithers, Matthieu Bourdon, Alex Guyon, Philip Carella, Ross Carter, Raymond Wightman, Sebastian Schornack, Henrik Jönsson, Sarah Robinson (2023)  Stiffness transition of new cell walls differs between Marchantia polymorpha gemmae and Arabidopsis thaliana leaves following cell division. PNAS

DOI: 10.1073/pnas.2302985120

 

Funding

This research was supported by individual Fellowships from Politecnico di Milano, Gatsby Charitable Foundation and Royal Society.

 

Open Access Resources 

All data has been uploaded on the Zenodo repository (doi: 10.5281/zenodo.7685356). All codes developed to analysed the data within the project are freely available on GitHub (https://github.com/alebonfanti/plant-cell-division-growth).

END

[Attachments] See images for this press release:
How new plant cell walls change their mechanical properties after cell division How new plant cell walls change their mechanical properties after cell division 2 How new plant cell walls change their mechanical properties after cell division 3

ELSE PRESS RELEASES FROM THIS DATE:

Study shows how ‘superbacteria’ were prevented from spreading in a large tertiary hospital

2023-10-02
Rapid identification of patients contaminated by “superbacteria” known as “carbapenem-resistant Enterobacteriaceae” (CRE), with early isolation of these patients, reduces transmission in hospital emergency departments. However, keeping them in the emergency room (ER) for more than two days undermines containment because it increases the risk of infection via colonization. These are the key findings of a study by a group at the University of São Paulo’s Medical School (FM-USP) in Brazil. An article on the study is published in the journal Clinical Infectious Diseases. Enterobacteria ...

MDMA increases feelings of connection during conversation, showing promise for therapy

2023-10-02
MDMA, commonly known as ecstasy, is a recreational psychedelic drug often used at parties and dance clubs because it creates feelings of closeness and social connection with others. Because of this “empathogenic” effect, researchers are also interested in its potential use as a complement to traditional talk therapy. In fact, two recent successful clinical trials support the use of MDMA-assisted therapy as a treatment for post-traumatic stress disorder (PTSD). Researchers at the University of Chicago published a study in Scientific Reports on September 22, 2023, that looked more closely at the pharmacological ...

Internationally recognized thoracic oncologist Dr. Taofeek K. Owonikoko named Executive Director of the University of Maryland Marlene and Stewart Greenebaum Comprehensive Cancer Center

Internationally recognized thoracic oncologist Dr. Taofeek K. Owonikoko named Executive Director of the University of Maryland Marlene and Stewart Greenebaum Comprehensive Cancer Center
2023-10-02
University of Maryland School of Medicine (UMSOM) Dean Mark T. Gladwin, MD, and University of Maryland Medical Center (UMMC) President and CEO Bert W. O’Malley, MD, announced today that Taofeek K. Owonikoko, MD, PhD, a distinguished physician-scientist with a global reputation in thoracic oncology, has been appointed Executive Director of the University of Maryland Marlene and Stewart Greenebaum Comprehensive Cancer Center (UMGCCC). Dr. Owonikoko will join the UMSOM faculty as the Marlene and Stewart Greenebaum Professor in Oncology in the Department of Medicine and Executive Director of the UMSOM ...

Meat taxes and other livestock emissions regulations could be feasible, acceptable and effective, argue climate researchers

2023-10-02
Meat taxes and other livestock emissions regulations could be feasible, acceptable and effective, argue climate researchers. #### Article URL: https://journals.plos.org/climate/article?id=10.1371/journal.pclm.0000291 Article Title: High ‘steaks’: Building support for reducing agricultural emissions Author Countries: Germany, UK Funding: This work was financially supported by the Robert Bosch foundation (Junior Professorship grant to LM) The funder had no role in study design, data collection and analysis, decision to publish, ...

Accelerated radiation treatment could reduce head and neck cancer patient burden in low- and middle-income countries

2023-10-02
SAN DIEGO, October 2, 2023 — A type of head and neck cancer predominantly diagnosed in people who reside in low- and middle-income countries may be treated effectively with fewer, but higher doses of radiation, a large new international study suggests. The study – a randomized phase III clinical trial involving 10 countries across four continents – found delivering a course of radiation in 20 rather than 33 treatment sessions was just as effective at controlling cancer for patients with alcohol and tobacco-related, locally advanced disease, without increasing side ...

October issues of American Psychiatric Association journals look at factors influencing depression and PTSD, guidance on handling drugs laced with fentanyl, and more

2023-10-02
The latest issues of three of the American Psychiatric Association’s journals, The American Journal of Psychiatry, Psychiatric Services and The American Journal of Psychotherapy are now available online. The October issue of The American Journal of Psychiatry is focused on research devoted to understanding factors influencing depression, PTSD, and suicidal behavior. Highlights include: Genetic Contribution to the Heterogeneity of Major Depressive Disorder: Evidence From a Sibling-Based Design Using Swedish National Registers. Maternal Perinatal Stress Trajectories and Negative Affect and Amygdala Development in Offspring. Networks of Neurodevelopmental Traits, Socioenvironmental ...

Men with metastatic prostate cancer live longer thanks to new drugs

Men with metastatic prostate cancer live longer thanks to new drugs
2023-10-02
Survival rates for men with metastatic prostate cancer have increased by an average of six months, something which coincides with the gradual introduction of ‘dual treatment’ since 2016. This is according to a register study of all Swedish men diagnosed between 2008 and 2020. The results are published in the medical journal JAMA Network open. Dual treatment means that patients receive both standard hormone therapy (GnRH therapy) and chemotherapy or androgen receptor blockers. Research has previously shown that men receiving this treatment live approximately one year longer than those receiving GnRH treatment alone. “Dual treatment for men with newly diagnosed metastatic ...

A more effective experimental design for engineering a cell into a new state

2023-10-02
A strategy for cellular reprogramming involves using targeted genetic interventions to engineer a cell into a new state. The technique holds great promise in immunotherapy, for instance, where researchers could reprogram a patient’s T-cells so they are more potent cancer killers. Someday, the approach could also help identify life-saving cancer treatments or regenerative therapies that repair disease-ravaged organs. But the human body has about 20,000 genes, and a genetic perturbation could be on a combination of genes or on any of the over 1,000 transcription factors that regulate the genes. ...

How the hippocampus distinguishes true and false memories

2023-10-02
Let’s say you typically eat eggs for breakfast but were running late and ate cereal. As you crunched on a spoonful of Raisin Bran, other contextual similarities remained: You ate at the same table, at the same time, preparing to go to the same job. When someone asks later what you had for breakfast, you incorrectly remember eating eggs. This would be a real-world example of a false memory. But what happens in your brain before recalling eggs, compared to what would happen if you correctly recalled cereal? In a paper published in Proceedings ...

Drier savannas, grasslands store more climate-buffering carbon than previously believed

2023-10-02
Photos Savannas and grasslands in drier climates around the world store more heat-trapping carbon than scientists thought they did and are helping to slow the rate of climate warming, according to a new study.   The study, published online Oct. 2 in Nature Climate Change, is based on a reanalysis of datasets from 53 long-term fire-manipulation experiments worldwide, as well as a field-sampling campaign at six of those sites.   Twenty researchers from institutions around the globe, including two at the University of Michigan, looked at where and why fire has changed the amount of carbon stored in topsoil. They found that within savanna-grassland regions, ...

LAST 30 PRESS RELEASES:

Heart failure in space: scientists calculate potential health threats facing future space tourists in microgravity

Experts offer guidance on talking with children about racism at pediatrician's office

Drugs for HIV and AIDS trialed as brain tumor treatment for first time

Breakthrough in nanoscale force measurement opens doors to unprecedented biological insights

Scientists discover new behavior of membranes that could lead to unprecedented separations

When inflicting pain on others pays off T

The Lancet: Managing gestational diabetes much earlier in pregnancy can prevent complications and improve long-term health outcomes, experts say

New study finds dinosaur fossils did not inspire the mythological griffin

NASA astronaut Woody Hoburg to deliver keynote address at ISSRDC focused on developing a space workforce

Study: Fatigue-management training improved sleep, safety, well-being for Seattle police

Guiding humanity beyond the moon: OHIO’s Nate Szewczyk and students coauthor papers published in “Nature” journals that revolutionize human space biology

Grant supports research to identify barriers to health care for Black women

Scientists at uOttawa develop innovative method to validate quantum photonics circuits performance

New report on community-centered approach to providing vaccine education and resources to persons experiencing homelessness during COVID-19

Government updates race and ethnicity data collection standards: implications and insights

Dr. Vivek S. Kavadi named CEO of the American Society for Radiation Oncology (ASTRO)

Dietary sucrose determines activity of lithium on gene expression and lifespan in drosophila melanogaster

Assessment of CEA, CA-125, and CA19-9 as adjuncts in non-small cell lung cancer management

Iron meteorites hint that our infant solar system was more doughnut than dartboard

Anti-trust regulators should consider their options carefully when start-ups are acquired, new study suggests

Family conditions may have more of an impact on upward social mobility than gender inequality

People with higher weight, and those who have high-quality experiences with higher-weight people, report less weight bias, per social psychology study of US adults

In two separate clinical studies, combined immunotherapy approach enhances cancer patient response

Airborne mapping reveals roles for biogenic sources and temperature in air pollution emissions in Los Angeles

Old bombs reveal new insights: Plants store more carbon, but for a shorter time frame, than we thought

The time it takes a person to decide can predict their preference

Hurricane changed ‘rules of the game’ in monkey society

Researchers widely observe yet seldom publish about same-sex sexual behavior in primates and other mammals - often because it is perceived to be rare

Wild chimpanzees seek out medicinal plants to treat illness and injuries

New catalyst unveils the hidden power of water for green hydrogen generation

[Press-News.org] How new plant cell walls change their mechanical properties after cell division
Biomechanics reveals cell wall age properties and how newly born cells can change their local shape and influence the growth of plant organs