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.
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.
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
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
Dr. Patrick Schweizer, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Corrensstrasse 3, D-06466 Seeland, firstname.lastname@example.org
Dr Alan Little, University of Adelaide, Adelaide, Australia, email@example.com
Dr. Sabine Odparlik, Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben,
Corrensstrasse 3, D-06466 Seeland, firstname.lastname@example.org
Dr. Sabine Odparlik | idw - Informationsdienst Wissenschaft
New research recovers nutrients from seafood process water
31.10.2018 | Chalmers University of Technology
Plant Hormone Makes Space Farming a Possibility
17.10.2018 | Universität Zürich
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
16.11.2018 | Health and Medicine
16.11.2018 | Life Sciences
16.11.2018 | Life Sciences