Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The sweet potato and it´s evolutionary traces

28.08.2017

The sweet potato is getting more and more popular in our local kitchen. The relationship to our normal potato is distant but nevertheless the usage of these two ingredients, like mashed or as fries, is quite similar. How astonishing complex the genome of the sweet potato is was revealed now in the journal Nature Plants by scientists from the Chenshan Botanical Garden (CSBG) in Shanghai, the Max Planck Institute for Molecular Genetics (MPIMG) in Berlin, the Shanghai Institute of Plant Physiology and Ecology (SIPPE), the Max Planck Institute of Molecular Plant Physiology (MPIMP) in Potsdam and the Tai’an Academy of Agricultural Sciences (TAAS) in Shandong.

Besides the research in model plants like Arabidopsis thaliana, studies in crop plants is focused by many scientists worldwide. Goals are to gain basic knowledge about different plants as well as reaching breeding aims like the improvement of yield or a higher resistance against changing environmental conditions. In regard to the growing world population these aims are important steps for future food assurance.


The hexaploid sweet potato has six copies of each chromosome.

Jun Yang

The unraveling of the plant genome is the first step for a better understanding. Some of Germany´s most important crop plants are potato and wheat which hence are both well studied and characterized. Within the following study a better understanding of another important crop plant was achieved.

Researchers from five different research institutes in China and Germany were able to sequence the complete genome of the sweet potato Ipomoea batatas. This plant belongs to the family Convolvulaceae and with a production of more than 100 million tons being the seventh most important crop in the world and the fourth most significant crop of China.

In advance it was already predicted that the sweet potato, having 90 chromosomes and being a hexaploid organism, would be no easy species for a complete sequencing project. The amount of chromosomes is high compared to many other plants but the phenomenon of polyploidy can be found as well in many other plants as for example in the hexaploid wheat.

Polyploidy is characterized by having more than a normal diploid set of chromosomes (2n) in the genome, in the case of sweet potato and wheat each homologous chromosome is present six times. How is a duplication of chromosomes possible and what is the result for the plants which is affected?

A whole-genome duplication event can be caused by an incorrect separation of the chromosomes within the meiosis phase. Reasons for this malfunction are manifold and can include spontaneous mutations, poison or even just environmental conditions like cold. The impact of such a polyploidization event can be severe and even lethal. Nevertheless in plant species this phenomenon can be as well neutral or positive and lead to an accelerated evolution.

A remarkable example can be found in the evolution of wheat since the hexaploid durum wheat (6n) arose from the diploid einkorn wheat (2n). This was possible by spontaneous crosses of the einkorn wheat with several diploid wild grasses which accumulated the chromosome number up to the current hexaploid state in the durum wheat.

In the current issue of Nature Plants the researchers show that the nowadays sweet potato has gone through a similar evolution 500.000 years ago. Ancestors have been a diploid and a tetraploid plant which cross lead to the hexaploid Ipomoea batatas. They developed a novel haplotyping method with which they are able to predict the origin of the single chromosomes.

Furthermore they could show that quite a number of genes have accumulated deleterious mutations on different alleles. This leads to the assumption that the selection pressure on the redundant chromosomes is much lower and hence that the ploidization event can drive an evolutionary advantage. In other words: due to the existence of six instead of two copies of the genome the accumulation of deleterious mutations is without a negative impact for the sweet potato.

Contact
Prof. Alisdair Fernie
Max Planck Institute of Molecular Plant Physiology
Phone +49331/567 8211
fernie@mpimp-golm.mpg.de

Dr. Jana Dotzek and Dr. Ulrike Glaubitz
Public Relations Officers
Max Planck Institute of Molecular Plant Physiology
Phone +49331/567 8211
pr@mpimp-golm.mpg.de
http://www.mpimp-golm.mpg.de

Jun Yang, M-Hossein Moeinzadeh, Heiner Kuhl, Johannes Helmuth, Peng Xiao, Stefan Haas, Guiling Liu, Jianli Zheng, Zhe Sun, Weijuan Fan, Gaifang Deng, Hongxia Wang, Fenhong Hu, Shanshan Zhao, Alisdair R Fernie, Stefan Boerno, Bernd Timmermann, Peng Zhang & Martin Vingron. Haplotype-resolved sweet potato genome traces back its hexaploidization history. Nature Plants, 2017; DOI: 10.1038/41477-017-0002.

Weitere Informationen:

http://www.mpimp-golm.mpg.de/2154967/sweet-potato

Dr. Ulrike Glaubitz | Max-Planck-Institut für Molekulare Pflanzenphysiologie

More articles from Life Sciences:

nachricht Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>