Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fungal intruder ante portas!

19.08.2016

An international research team found new targets to strenghten cell walls against the powdery mildew pathogen in barley

An international research team with participation of the Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK)/ Germany and the University of Adelaide/ Australia has provided new targets for the generation of enhanced disease resistance against the powdery mildew pathogen in barley.


Electron microscopic image of barley papilla and powdery mildew appressorium.

Twan Rutten/ IPK

Until now the role of the cell-wall components callose and cellulose in penetration resistance of crop species have been largely unknown, because the genes involved in the observed callose and cellulose accumulation have not been identified unequivocally.

By silencing of the HvCslD2 or the HvGsl6 gene the research team has shown that its down regulation is associated with lower accumulation of callose as well as cellulose and higher susceptibility of barley plants to penetration by the fungal pathogen. This indicates that callose and cellulose contribute to the barley fungal penetration resistance.

In the plant and pathogen co-evolutionary battleground, host plants have evolved a wide range of defence strategies against attacking pathogens. One of the earliest observed defence responses is the formation of cell-wall thickenings called papillae at the site of infection. The papillae are cellular reinforcements formed by depositing polysaccharides between the wall and the plasma membrane.

In case of barley, which was the main focus of the study, the papillae contain callose and cellulose beside other polysaccharides. It was already known that overexpression of the stress-induced callose synthase gene AtGsl5 from the model plant Arabidopsis induced penetration resistance to the powdery mildew pathogen. The research team expected, that there would be an AtGsl5 ortholog present in most monocot species like barley that might mediate callose accumulation during fungal infections.

Thus they employed a comparative genomics approach between Arabidopsis and a series of representative monocot species including barley. A phylogenetic analysis revealed that the gene HvGsl6 has close sequence similarity with AtGs15.

  Transcript profile analysis and transient-induced gene silencing showed that the HvGsl6 transcript is significantly upregulated following powdery mildew infection and that reduced HvGsl6 transcript levels lead to both, decreased accumulation of callose in the papillae and increased susceptibility of barley against the well adapted fungal pathogen.

Very similar results were obtained by silencing a second gene, HvCslD2, which encodes for the cellulose-synthase like protein D2 of barley. Here, the level of accumulating cellulose was reduced and plants suffered not only from enhanced infection by the barley- but also from the wheat powdery mildew, for which barley is normally not a host. In line with the proposed protective function of HvCslD2 in barley its over-expression enhanced resistance.

“The association of the plant cell wall with fungal penetration resistance provides new targets for the improving disease resistance in cereal crops. The identification of the genes involved in the biosynthesis of each papilla component is a major step towards achieving this goal says Dr Alan Little, Senior Research Scientist with the ARC Centre of Excellence in Plant Cell Walls, at the University of Adelaide.

“Our results show that the novel gene HvCslD2 is an interesting target for improving disease resistance in barley and maybe other cereals. It probably acts by making cell-walls of the “plant fortress” less easily penetrated by fungal pathogens ante portas. Now we have to find beneficial alleles for this gene for introgression into modern barley” explains Patrick Schweizer, head of the Pathogen-Stress Genomics lab at the Leibniz-Institute of Plant genetics and crop Plant Research (IPK) in Gatersleben.

Publications:

Douchkov, D., Lueck, S., Hensel, G., Kumlehn, J., Rajaraman, J., Johrde, A., Doblin, M. S., Beahan, C. T., Kopischke, M., Fuchs, R., Lipka, V., Niks, R. E., Bulone, V., Chowdhury, J., Little, A., Burton, R. A., Bacic, A., Fincher, G. B. and Schweizer, P. (2016), The barley (Hordeum vulgare) cellulose synthase-like D2 gene (HvCslD2) mediates penetration resistance to host-adapted and nonhost isolates of the powdery mildew fungus. New Phytol. doi:10.1111/nph.14065
(URL: http://onlinelibrary.wiley.com/doi/10.1111/nph.14065/epdf)

Chowdhury J., Schober M.S., Shirley N.J., Singh R.R., Jacobs A.K., Douchkov D., Schweizer P., Fincher G.B., Burton R.A. and Little A. (2016). Down-regulation of the glucan synthase-like 6 gene (HvGsl6) in barley leads to decreased callose accumulation and increased cell wall penetration by Blumeria graminis f. sp. hordei. New Phytol. doi: 10.1111/nph.14086
(URL: http://onlinelibrary.wiley.com/doi/10.1111/nph.14086/epdf)

Further Information:

Dr. Patrick Schweizer, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Corrensstrasse 3, D-06466 Seeland, schweizer@ipk-gatersleben.de

Dr Alan Little, University of Adelaide, Adelaide, Australia, alan.little@adelaide.edu.au

Press Contact:

Dr. Sabine Odparlik, Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben,
Corrensstrasse 3, D-06466 Seeland, odparlik@ipk-gatersleben.de

Weitere Informationen:

http://onlinelibrary.wiley.com/doi/10.1111/nph.14065/epdf
http://onlinelibrary.wiley.com/doi/10.1111/nph.14086/epdf

Dr. Sabine Odparlik | idw - Informationsdienst Wissenschaft

More articles from Agricultural and Forestry Science:

nachricht Light green plants save nitrogen without sacrificing photosynthetic efficiency
21.11.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign

nachricht Filling intercropping info gap
16.11.2017 | American Society of Agronomy

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

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

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>