Office hours for students: Mo, 13-14:00, room 42A 320.
Other times and during semester break upon request.
Arabidopsis and Asian Soybean Rust
The Project
Plants are continuously exposed to a wide range of pathogens which are present everywhere in nature. Nevertheless, visibly sick plants with diesease symptoms caused by pathogen growth are rather rarely observed in nature - most plants are resistant. This widespread and stable resistance type is based on specific plant mechanisms and also called nonhost resistance (NHR).
In our research group, we analyze the nonhost interaction of the model plant Arabidopsis thaliana to the biotrophic fungal plant pathogen Phakopsora pachyrhizi, causing Asian soybean rust (ASR) on soybean plants (see Figure 1) by using methods of molecular biology and microscopy.
Figure 1: Soybean leaflet with ASR rust pustules (B) in comparison to healthy leaflet (A)
The model plant Arabidopsis shows postpenetration nonhost resistance to this pathogen. This means that in most interaction sites, fungal growth is stopped after penetration of the epidermis (see Figure 2). In contrast, host plants such as soybean allow fungal growth within the mesophyll layer (see Figure 2) which results in extensive sporulation starting around nine days after the infection.
ASR has developed to a serious threat of soybean production during the last decades. Originally discovered in Japan, it is now established in all major soybean growing areas worldwide including the U.S. Importantly, no resistant variety is commercially available.
High yield losses up to 80 % are a consequence and additional costs raise high due to extensive use of fungicides. This, in turn, results in strong environmental impact on flora and fauna in and around soybean growing areas. Therefore, breeding of resistant varieties is a major concern and identification of resistance sources is required.
Figure 2: Scheme of P. pachyrhizi development on soybean and Arabidopsis during the first 48 hours after inoculation
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 P. pachyrhizi to answer the following questions:
- Which genes mainly contribute to NHR establishment?
- By which mechanisms do the corresponding gene products protect Arabidopsis from P. pachyrhizi?
- Can we use this knowledge to confer resistance to the major host of the pathogen, the soybean crop?
Definitions
- ASR
- Asian soybean rust, a fungal plant disease caused by Phakopsora pachyrhizi
- Nonhost resistance (NHR)
-
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 worked on maize genetics in the lab of Virginia Walbot at Stanford University, USA. During her PhD she became attached to her so far favorite research subject molecular plant pathology at the Max-Planck Institute for Plant Breeding Research (MPIPZ) 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 in Aachen 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 August 2009 as a junior professor in Aachen. She and her team are working on molecular mechanisms of Arabidopsis nonhost resistance against Asian soybean rust. Katharina is funded by BASF Plant Science and the Excellence Initiative of the German federal and state governments.
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. Here, she aims at identifying binding partners of NHR key proteins using a pull-down approach. In a joint project together with group members of Uwe Conrath and Ulrich Schaffrath (both RWTH Aachen) she works on the identification of P. pachyrhizi effector proteins. Ruth is funded by the RFwN Graduiertenförderung and has recently been awarded a DAAD fellowship for a conference visit.
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 elucidating mechanisms of haustoria formation. Here, he identified multiple genes with a prominent role in prehaustorial resistance of Arabidopsis to P. pachyrhizi by using dsRNAi-mediated silencing and overexpression of candidate genes obtained from his microarray study in different genetic backgrounds. Caspar is funded by RWTH seed funds and was recently awarded a DAAD fellowhsip for a conference visit.
langenbach(at)bio3.rwth-aachen.de
Tel: +49 (0)241-8026662
Anna-Christin Joel, Master student
Anna-Christin studies Biology at the RWTH Aachen, worked on plant insect interactions during her Bachelor thesis in Nikolaus Schlaich's lab (RWTH Aachen) and is currently analysing a group of candidate genes with suspected function in NHR establishment of Arabidopsis to P. pachyrhizi. She is eager to learn about infection-dependent phosphorylation of her candidate gene products as well as the functional range of these proteins in NHR by analyzing respective mutants in other nonhost pathosystems.
anna.christin.joel(at)rwth-aachen.deTel: +49 (0)241-8026662
Nikola Kuehr, Diploma student
Nikola studies Biology at the RWTH Aachen and is currently doing her Diploma thesis working on the characterization of members of a plant-specific gene family with regard to their role in NHR of Arabidopsis to P. pachyrhizi. She is testing several members of this family by studiyng the effect of knockdown and overexpression in multiple pathosystems. In addition, she performs enzymatic assays to obtain hints about gene product function.
nikola.kuehr(at)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: Nikola, Antonia, Anna-Christin, Ruth, Caspar and Katharina
Research internships, Diploma-, Bachelor- and Master theses can be performed anytime. Please contact Prof. Göllner for more information.
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
Literature management
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 Vertiefungsmodul Molekular- und Zellbiologie der Pflanzen (B.Sc., 5th semester)
Forschungspraktikum (B.Sc., M.Sc.)
See CAMPUS RWTH for further details.