Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Parental Conflict in Plants: Maternal Factors Silence Paternal Genes

30.05.2011
In flowering plants, the beginning of embryogenesis is almost exclusively governed by maternal gene activity. Maternal factors regulate the development of the embryo and silence paternal genes during early stages of development.

This finding – obtained using next generation sequencing technology – was reported by an international team of researchers including plant geneticists from the University of Zurich. This newly uncovered mechanism may be involved in the maintenance of species boundaries and could play an important role in the development of novel crop varieties.

Mother and father each contribute one half of the genetic information to their offspring. Thus, it was thought that both parents contribute equally to the development of the next generation. Indeed, this holds true for late stages of embryo development in plants, but early on, things are quite different: during the earliest phase of embryo development - from the fertilized egg to the globular stage - predominantly the maternal genes are active. This phase of development is controlled largely by maternal factors, which actively repress or silence the genes inherited from the father. This surprising finding was recently published in the renowned American journal CELL, by an international team of scientists led by plant geneticists from the Universities of Zurich and Montpellier.

Silenced Paternal Genes

For their analysis, the Zürich scientists crossed two genetically distinguishable races of the model plant Arabidopsis thaliana (tale cress) and analyzed the relative contributions of the parental genomes shortly after the first division of the fertilized egg. Such molecular genetic analyses of plant embryos at very early stages are technically challenging, which explains why up to now researchers resorted to studying embryos at later stages. But Ueli Grossniklaus, Professor for Plant Developmental Genetics at University of Zurich, has a marked preference for tackling experimentally challenging problems, including the study of gametes and very young embryos that are hard to obtain.

Using "Next Generation Sequencing", a novel and powerful technology, Grossniklaus and colleagues were able to show that in an early phase of plant embryo development, predominantly maternal genes are active. Via small ribonucleic acid molecules (siRNAs), the maternal genome controls paternal genes to ensure that, initially, most remain inactive.

In the course of development, paternal genes are sucessively activated, which also requires the activity of maternal factors. This finding is surprising because it contradicts earlier findings, which suggested that these siRNAs have a specifc role in preventing "jumping genes" (transposons) to move within the genome.

According to Grossniklaus, the transient silencing of the paternal contribution during early development of the offspring is in the mother plant’s best interest: the mother invests considerable resources into the formation of seeds. Before making this investment, the mother verifies the paternal contribution to the progeny for compatibility with her own genome. If the father’s genome is too divergent from her own, e.g., originating from a different species, the embryo will die.

In fact, the two parental plants have opposing interests with regard to their offspring. The pollen-donating father is interested in maximizing transfer of resources from the mother to the offspring. By contrast, the mother plant aims at optimizing the match with the fathers genome in order to prevent a waste of resources. „We are dealing with a classical parental conflict“, Ueli Grossniklaus summarizes the opposing interests.

Maternal Control May Ensure the Maintenance of Species Boundaries

Maternally active genes direct and control early embryogenesis. Genetic incompatibility will cause embryos to abort, such that fertilization with pollen from other plant species is not successful. Therefore, the mechanism unraveled by Grossniklaus and colleagues may play an important role in the maintenance of species barriers. This may also explain why attempts to cross crop plants with their wild relatives, e.g., to transfer disease-resistance genes present in wild relatives to crops, often fail early in embryogenesis. A genetic divergence between the parents that is too large may be recognized by this novel mechanism, leading to embryo abortion. Commercial crop breeders will thus be interested in finding out how the maternal control of early plant embryo development can be circumvented in their breeding programs.

Reference:
Daphné Autran, Célia Baroux, Michael T. Raissig, Thomas Lenormand, Michael Wittig, Stefan Grob, Andrea Steimer, Matthias Barann, Ulrich C. Klostermeier, Olivier Leblanc, Jean-Philippe Vielle-Calzada, Philip Rosenstiel, Daniel Grimanelli and Ueli Grossniklaus, Maternal Epigenetic Pathways Control Parental Contributions to Arabidopsis Early Embryogenesis, Cell (2011), doi: 10.1016/j.cell.2011.04014.
Contact:
Prof. Dr. Ueli Grossniklaus, University of Zürich, Institute of Plant Biology, Tel. +41 44 634 82 40

E-Mail: grossnik@botinst.uzh.ch

Beat Müller | idw
Further information:
http://www.mediadesk.uzh

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Supersensitive through quantum entanglement

28.06.2017 | Physics and Astronomy

X-ray photoelectron spectroscopy under real ambient pressure conditions

28.06.2017 | Physics and Astronomy

Mice provide insight into genetics of autism spectrum disorders

28.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>