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 Rapid adaptation to a changing environment
28.04.2016 | Christian-Albrechts-Universität zu Kiel

nachricht Tiny microscopes reveal hidden role of nervous system cells
28.04.2016 | Salk Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: ORNL researchers discover new state of water molecule

Neutron scattering and computational modeling have revealed unique and unexpected behavior of water molecules under extreme confinement that is unmatched by any known gas, liquid or solid states.

In a paper published in Physical Review Letters, researchers at the Department of Energy's Oak Ridge National Laboratory describe a new tunneling state of...

Im Focus: Bionic Lightweight Design researchers of the Alfred Wegener Institute at Hannover Messe 2016

Honeycomb structures as the basic building block for industrial applications presented using holo pyramid

Researchers of the Alfred Wegener Institute (AWI) will introduce their latest developments in the field of bionic lightweight design at Hannover Messe from 25...

Im Focus: New world record for fullerene-free polymer solar cells

Polymer solar cells can be even cheaper and more reliable thanks to a breakthrough by scientists at Linköping University and the Chinese Academy of Sciences (CAS). This work is about avoiding costly and unstable fullerenes.

Polymer solar cells can be even cheaper and more reliable thanks to a breakthrough by scientists at Linköping University and the Chinese Academy of Sciences...

Im Focus: Ultra-thin glass is up and coming

As one of the leading R&D partners in the development of surface technologies and organic electronics, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP will be exhibiting its recent achievements in vacuum coating of ultra-thin glass at SVC TechCon 2016 (Booth 846), taking place in Indianapolis / USA from May 9 – 13.

Fraunhofer FEP is an experienced partner for technological developments, known for testing the limits of new materials and for optimization of those materials...

Im Focus: Measuring the heat capacity of condensed light

Liquid water is a very good heat storage medium – anyone with a Thermos bottle knows that. However, as soon as water boils or freezes, its storage capacity drops precipitously. Physicists at the University of Bonn have now observed very similar behavior in a gas of light particles. Their findings can be used, for example, to produce ultra-precise thermometers. The work appears in the prestigious technical journal "Nature Communications".

Water vapor becomes liquid under 100 degrees Celsius – it condenses. Physicists speak of a phase transition. In this process, certain thermodynamic...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

The “AC21 International Forum 2016” is About to Begin

27.04.2016 | Event News

Soft switching combines efficiency and improved electro-magnetic compatibility

15.04.2016 | Event News

Grid-Supportive Buildings Give Boost to Renewable Energy Integration

12.04.2016 | Event News

 
Latest News

Possible Extragalactic Source of High-Energy Neutrinos

28.04.2016 | Physics and Astronomy

University of Illinois researchers create 1-step graphene patterning method

28.04.2016 | Materials Sciences

Rapid adaptation to a changing environment

28.04.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>