Arabidopsis and Asian Soybean Rust
The Project
Plants are continuously exposed to a wide range of pathogens which are present everywhere in nature. Nevertheless, plants which are visibly sick due to symptoms caused by pathogen growth can be observed rather rarely in nature - most plants are resistant. This widespread resistance type is based on specific plant mechanisms and also called nonhost resistance.
In our research group, we analyze the nonhost interaction of the model plant Arabidopsis thaliana to a biotrophic fungal plant pathogen, the Asian Soybean Rust (ASR; Phakopsora pachyrhizi, see Figure 1) by using methods of molecular biology and microscopy.
Figure 1: Soybean leaflet with ASR-caused rust pustules (B) in comparison to healthy leaflet (A)
Figure 2: Scheme of ASR development on soybean and Arabidopsis during the first 48 hours after inoculation
Arabidopsis shows post-penetration resistance to this pathogen. This means that in most interaction sites, fungal growth is stopped after penetration of the epidermis. In contrast, host plants such as soybean allow intense fungal growth and sporulation (see Figure 2).
ASR has developed to a serious threat of soybean production during the last decades. Originally discovered in Japan, it settled down in all major soybean growing areas of the world including the U. S. and no resistant variety is commercially available. Consequently, great yield losses up to 80 % can be observed and additional costs (direct and indirect) emerge caused by the use of fungicides.
To learn more about the disease and putative resistance mechanisms, we are using molecular genetic techniques to identify the basic mechanisms of Arabidopsis’ nonhost resistance to ASR to answer the following questions:
- How is this nonhost resistance established in the plant?
- Can we use this knowledge to confer resistance to the main host of the pathogen, the soybean crop?
Definitions
- ASR
- Asian soybean rust, Phakopsora pachyrhizi
- Bgh
- Blumeria graminis forma specialis (f. sp.) hordei
- Nonhost resistance
-
If all varieties of a plant species is resistant against all isolates of a pathogen species, this plant shows nonhost resistance.
Katharina Göllner, Group leader
Katharina studied Biology at the Freie Universität in Berlin and the Università degli Studi di Parma, Italy, with emphasis on plant biology and genetics. For her diploma thesis she studied maize genetics in the lab of Virginia Walbot at Stanford University, USA. During her PhD she came in contact with her favorite research subject molecular plant pathology at the Max-Planck Institute for Plant Breeding Research (MPIZ) in Cologne, where she worked on powdery mildew resistance of Arabidopsis in the lab of Ralph Panstruga in the department of Paul-Schulze Lefert. In 2006 she joined Uwe Conrath's group as a postdoc and started working on resistance of Arabidopsis to Asian soybean rust. Based on this work, she was able to establish her own group in Aachen in August 2009 as a junior professor. She and her team are working on molecular mechanisms of Arabidopsis nonhost resistance against Asian soybean rust. Katharina is funded by BASF Plant Science.
goellner(at)bio3.rwth-aachen.de
Tel: +49 (0)241-8026662
Ruth Campe, PhD student
Ruth studied Biology at the RWTH Aachen and the Université Claude Bernard Lyon 1. After finishing her diploma thesis working on candidate genes in the nonhost interaction of ASR and Arabidopsis, she continues her work as a PhD student working on molecular mechanisms of nonhost resistance establishment. Ruth is funded by the RFwN Graduiertenförderung.
campe(at)bio3.rwth-aachen.de
Tel: +49 (0)241-8026662
Caspar Langenbach, PhD student
Caspar studied Biology at the RWTH Aachen and worked on elucidation of plant responses to ASR infection during his diploma thesis. Since 2008 he extended his studies to whole-genome molecular analyses during his PhD, aiming at the elucidating mechanisms of haustoria formation. Caspar is funded by the RWTH seed funds.
langenbach(at)bio3.rwth-aachen.de
Tel: +49 (0)241-8026662
Further projects (B.Sc., research internships) employ methods such as transient transformation of Arabidopsis, fluorescence microscopy, quantitative PCR and virus-induced gene silencing.
from left: Vera, Caspar, Stephani, Ruth and Katharina
Research internships, Diploma-, Bachelor- and Master theses can be performed anytime.
Motivated students aiming at working as a PhD or postdoctoral scientists interested to work within our group are encouraged to apply for a fellowship.
Visiting scientists who wish to perform specific experiments in our lab are always welcome!
In any case: Please contact Prof. Göllner for more information.
1. Soybean rust
Goellner K, Loehrer M, Langenbach C, Conrath U, Koch E, Schaffrath U (2009) Pathogen profile: Phakopsora pachyrhizi, the causal agent of Asian soybean rust. Molecular Plant Pathology 11(2): 169-177 link to publication
Loehrer M, Langenbach C, Goellner K, Conrath U, Schaffrath U (2008) Characterization of Nonhost Resistance of Arabidopsis to the Asian Soybean Rust. Molecular Plant-Microbe Interactions 21: 1421-1430 link to publication
Miles M, Frederick R, Hartman G (2003) Soybean Rust: Is the U.S. Soybean Crop At Risk? http://www.apsnet.org/online/feature/rust/
2. Nonhost resistance
Lipka U, Fuchs R, Lipka V (2008) Arabidopsis non-host resistance to powdery mildews. Curr Opin Plant Biol 11: 404-411
Lipka V, Dittgen J, Bednarek P, Bhat R, Wiermer M, Stein M, Landtag J, Brandt W, Rosahl S, Scheel D, Llorente F, Molina A, Parker J, Somerville S, Schulze-Lefert P (2005) Pre- and Postinvasion Defenses Both Contribute to Nonhost Resistance in Arabidopsis. Science 310: 1180-1183
3. General plant defense
Dodds PN, Rathjen JP (2010) Plant immunity: towards an integrated view of plant-pathogen interactions. Nat Rev Genet 11: 539-548
Jones JD, Dangl JL (2006) The plant immune system. Nature 444: 323 – 329
Sequence alignment
T-coffee for alignment of multiple sequences
ClustalW for classical alignments of multiple sequences
http://www.ebi.ac.uk/Tools/emboss/align/index.html for pairwise alignment
Protein analysis
http://www.expasy.org/tools/dna.html Translation of DNA into protein sequences
http://elm.eu.org/ finds functional sites in proteins
IntAct Protein interaction database
String Protein interaction database
N-Browse Protein interaction database
Sequence analysis, comparison and manipulation
http://www.ncbi.nlm.nih.gov/BlAST/ for Blast searches
Reverse complementation
ATHENA Promoter analyses
AtcisDB Arabidopsis cis-regulatory element database
Motif Finder Motif Analysis in Promoter or Upstream Gene Sequences
Databases for genomic sequences of Arabidopsis thaliana and Glycine max
http://www.arabidopsis.org
http://www.tigr.org/tdb/e2k1/ath1/ath1.shtml
http://www.ncbi.nlm.nih.gov/gquery/gquery.fcgi
http://phytozome.net
Primer design
Primer3 can exclude sequence parts and regards desired PCR product size
http://signal.salk.edu/tdnaprimers.2.html for T-DNA primer design
artificial miRNA design for efficient gene knockdown
Databases for expression analysis (microarrays) in Arabidopsis thaliana and Glycine max
https://www.genevestigator.ethz.ch/
http://www.plexdb.org
Literature mining
ISI Web of Knowledge Literature search
iHOP gives all citations of your gene of interest
PubMed Literature search
Soft Skill Seminar "Data Evaluation and Scientific Writing" (B.Sc., M.Sc.)
Seminar "Built to Resist: How plants defend themselves" (B.Sc., M.Sc.)
Practical course Phytochemie of the Vertiefungsmodul Pflanzenwissenschaften (B.Sc., 5th semester)
See CAMPUS RWTH for further details.