Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Gene for dissected leaves

14.02.2014
Arabidopsis thaliana lost the RCO gene over the course of evolution and thus forms simple leaves

Spinach looks nothing like parsley, and basil bears no resemblance to thyme. Each plant has a typical leaf shape that can differ even within the same family. The information about what shape leaves will be is stored in the DNA.


The thale cress has simple oval leaves, the hairy bittercress, in contrast, develops complex leaves with leavelets.

© MPI f. Plant Breeding Research/ Lempe


Thale cress leaves lack the RCO-gene and remain simple (left). In the leaves of the hairy bittercress (middle) the RCO-gene inhibits cell growth between sites of leaflet formation (right; blue: active RCO-gene).

© MPI f. Plant Breeding Research/ Lempe

According to researchers at the Max Planck Institute for Plant Breeding Research in Cologne, the hairy bittercress (Cardamine hirsuta) has a particular gene to thank for its dissected leaves. This homeobox gene inhibits cell proliferation and growth between leaflets, allowing them to separate from each other. The thale cress Arabidopsis thaliana does not have this gene. Therefore, its leaves are not dissected, but simple and entire.

Miltos Tsiantis and his colleagues at the Max Planck Institute for Plant Breeding Research in Cologne discovered the new gene when comparing two plants from the Brassicaceae family: Cardamine hirsuta has dissected leaves that form leaflets and Arabidopsis thaliana has simple leaves. The researchers identified the RCO (REDUCED COMPLEXITY) gene, which makes leaves of the hairy bittercress more complex. Arabidopsis lacks this gene and, accordingly, lacks leaflets. RCO is only active in growing leaves. RCO ensures that cell proliferation and growth is prevented in areas of the leaf margin between sites of leaflet formation. “The leaves of Arabidopsis are simple and entire because growth is not inhibited by the RCO gene,” explains Tsiantis. “If we had not compared the two plants we would never have discovered this difference, as it is impossible to find a gene where none exists,” he adds.

The scientists first identified the RCO gene through a mutation in the hairy bittercress. In the absence of functional RCO the hairy bittercress can no longer produces leaflets. The RCO gene belongs to a cluster of three genes, which arose during evolution through the duplication of a single gene. In the thale cress, the original triple cluster now consists of a single gene. When the scientists return the RCO gene to the thale cress in the laboratory, evolution is partially reversed. “The simple oval leaves of Arabidopsis now develop deep lobes” says Tsiantis, “The fact that the leaf shape becomes complex again through the transfer of the RCO gene alone, shows that most of the apparatus for the formation of leaflets must still be present in the thale cress and was not lost with the RCO gene.”

The research team also examined the RCO sequence in greater detail and found it is a Homeobox gene. These genes function like genetic switches in that they activate or deactivate other genes. The scientists also demonstrated that RCO function is restricted to leaf shape; it does not decide whether leaves actually form. The loss of the RCO gene does not give rise to any other visible changes in the hairy bittercress. Therefore, its effect is limited to the inhibition of growth on the leaf margin. RCO does not work with the plant hormone auxin here. This specificity makes RCO a more likely driver of leaf shape evolution than any other genes identified to date. Tsiantis and his colleagues aim to decode its exact functionality in the months to come.

The scientists also examined the two genes which form a cluster with RCO and which arose in the course of evolution through the duplication of a precursor gene. They wanted to find out how the novel function of RCO in promoting leaf complexity arose. Apparently, the main functional difference lies in the control regions of the genes and not in the protein sequences. The control regions dictate when and how the relevant gene is read. If one or other of the two genes is subjected to the effect of the RCO control region, Arabidopsis makes complex leaves. Thus, the dissected leaves of the hairy bittercress are primarily owed to the control region of the RCO gene.

Contact
Prof. Dr. Miltos Tsiantis
Max Planck Institute for Plant Breeding Research, Köln
Phone: +49 221 5062-106
Fax: +49 221 5062-107
Email: tsiantis@mpipz.mpg.de
Original publication
Daniela Vlad et al.
Leaf Shape Evolution Through Duplication, Regulatory Diversification, and Loss of a Homeobox Gene.

Science, February 14, 2014 (DOI: 10.1126/science.1248384)

Prof. Dr. Miltos Tsiantis | Max-Planck-Institute
Further information:
http://www.mpg.de/7924634/gene_for_plant_leaves_with_leaflets

More articles from Life Sciences:

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>