Ordinary cells have the ability to replace lost organs in plants—a function previously thought to be limited to stem cells—researchers at New York University's Center for Genomics and Systems Biology and Utrecht University in the Netherlands have found.
The findings, which suggest that some roles of stem cells in organ regeneration may be shared by other types of cells, are published in the latest issue of the journal Nature.
Stem cells have two known fundamental properties: they can renew themselves and they can give rise to specialized cells. These traits make them the engines for regeneration, creating new cells to replace lost organs and tissue. These phenomena are especially evident in plants, which continually re-grow their branches and roots. The center of stem cell activity is a stem cell niche, where stem cells are directed to perform these renewal and regeneration functions.
However, it's unclear how significant the stem cell niche is to organogenesis—the building and rebuilding of organs.
The scientists studied the plant Arabidopsis thaliana. The species is a good candidate for study because researchers have previously identified all of the genes expressed in its individual cells, which allows tracking of cells' identity as they regenerate.
In the study, the researchers cut off the plant's root tip, thereby excising the stem cell niche, and examined the return of cell identities by measuring all gene activity. The results suggested that stem cells returned quite late in regeneration after other cells were already replaced. The researchers then used mutant plants in which the stem cell niche no longer functions to confirm their initial observations. Despite the absence of the stem cell niche, the plant's ordinary cells worked to regenerate all the major tissues constituting the root tip—a process that began hours after it had been removed.
However, researchers found that plants without functional stem cell niches could not resume normal growth, showing that other cells did not replace all functions of stem cells.
Scientists have recently shown that manipulating non-stem cells in mammals to express several genes could convert those cells into stem cells—a process known as reprogramming. In 2008, a Nature study conducted at the Harvard Stem Cell Institute recreated pancreatic cells in mice into another type of cell that produces insulin without the aid of stem cells. In the NYU-Utrecht study, the researchers sought to determine if entire organs regenerate in plants absent of stem cells without using genetic manipulation.
"You could think of these findings as a massive reprogramming of an organ's identity without the need for a stem cell niche," said Kenneth Birnbaum, an assistant professor of biology at NYU whose lab conducted the research. "Here is a case of an organism that can perform this kind of reprogramming naturally. This may be one reason why plants are so adept at regenerating their body parts."
The work was supported by a grant from the National Institutes of Health.
James Devitt | EurekAlert!
Historical rainfall levels are significant in carbon emissions from soil
30.05.2017 | University of Texas at Austin
3D printer inks from the woods
30.05.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt
The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.
The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
30.05.2017 | Life Sciences
30.05.2017 | Power and Electrical Engineering
29.05.2017 | Earth Sciences