For the past few years, mildew has been able to infect triticale grain, which up to then had been resistant to this fungal disease. So how was the pathogen able to spread to a different host plant? Researchers from the University of Zurich have shown that the new pathogen is a genetic mix of existing mildew forms.
Triticale is an artificial grain type stemming from a cross between wheat and rye. Since the 1960s, triticale has been cultivated in many places as a feed grain and had proved very resistant to mildew attack. This fungal pathogen causes huge losses in cereal production.
In the case of wheat, for example, the fungus can reduce the harvest by up to 45%. But triticale fields were infected for the first time in 2001, and mildew is now being reported in many triticale growing regions in Europe.
Comparison of the mildew genome confirms: The new form is a hybrid
Researchers from the University of Zurich have now examined how the mildew managed to spread to triticale. To do this, they collected samples from infected grain fields all over Europe and examined the genetic information of different forms of mildew.
The genetic material (genome) of the pathogens that attack triticale, rye and wheat were then compared using bioinformatics. The comparisons showed that the new triticale fungus is a hybrid of the variants specialized in wheat and rye: 12.5% of the genome is identical to DNA sequences from the form specialized in rye, while 87.5% stems from the form specialized in wheat.
Evolution of the pathogen reflects the development of the host plant
This means that a hybrid from two mildew variants specialized in two different host plants can infect the cross between those two host plants. The study thus shows the manner in which mildew adapts to new host plants in a co-evolutionary way and can break down their resistance. The study also reveals that this recent evolutionary event was not a one-off occurrence.
Around 10,000 years ago, mildew overcame the resistance of bread wheat, which was relatively new at the time, in the same way. “These results are of major significance for treating and preventing plant diseases. The more we know about the evolutionary mechanisms of mildew, the better we can keep new cultivated plants resistant to the pathogens”, explains Thomas Wicker from the Institute of Plant Biology at the University of Zurich.
Fabrizio Menardo, Coraline R Praz, Stefan Wyder, Roi Ben-David, Salim Bourras, Hiromi Matsumae, Kaitlin E McNally, Francis Parlange, Andrea Riba, Stefan Roffler, Luisa K Schaefer, Kentaro K Shimizu, Luca Valenti, Helen Zbinden, Thomas Wicker & Beat Keller. Hybridization of powdery mildew strains gives raise to pathogens on novel agricultural crop species. Nature Genetics, 11 January 2016.
University Research Priority Program “Evolution in action”
This research project was carried out as part of the University Research Priority Program (URPP) “Evolution in action”. The University Research Priority Program “Evolution in action” examines evolutionary mechanisms using state-of-the-art methods from genomics and bioinformatics. Researchers from eight institutes and three faculties at the University of Zurich are involved in the projects of the URPP “Evolution in action”.
Melanie Nyfeler | Universität Zürich
The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences
Transforming plant cells from generalists to specialists
07.12.2016 | Duke University
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
07.12.2016 | Health and Medicine
07.12.2016 | Life Sciences
07.12.2016 | Health and Medicine