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 Toward a 'smart' patch that automatically delivers insulin when needed
18.01.2017 | American Chemical Society

nachricht 127 at one blow...
18.01.2017 | Stiftung Zoologisches Forschungsmuseum Alexander Koenig, Leibniz-Institut für Biodiversität der Tiere

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

A big nano boost for solar cells

18.01.2017 | Power and Electrical Engineering

Glass's off-kilter harmonies

18.01.2017 | Materials Sciences

Toward a 'smart' patch that automatically delivers insulin when needed

18.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>