Investigating the contribution of RipTAL effectors to Ralstonia solanaearum bacterial wilt disease

Background and project overview: With an increasing population, environmental degradation and dwindling natural resources, research into crop development has never been more important. Plant pathogens are a major threat to our plant-based food supply. During infection microbial plant pathogens secrete diverse effector proteins to block resistance and promote microbial disease. The transcription activator-like effectors (TALEs) of Xanthomonas spp. and their homologs from the bacterial wilt pathogen Ralstonia solanacearum, the RipTALs, are one such class of effectors.
These proteins are unusual in acting as transcription factors inside the host (for review see: Boch et al., 2014). After injection into the plant cell they bind specific effector binding elements (EBEs) in plant promoters and activate expression of downstream susceptibility (S) genes whose products benefit the bacterium.
DNA binding is carried out by the largest domain of the TALE, the repeat domain. The tandem-arranged, near-identical 34-amino acid repeats each bind one DNA base in the target sequence. Base specificity is defined by the amino acid at position 13, the base-specifying residue (BSR; de Lange et al., 2014). Base specificity of all BSRs - the TALE code - has by now been fully elucidated allowing prediction of targets in a host genome. We have been able to show that this sequence-specific DNA recognition mechanism is conserved among Xanthomonas TALEs and R. solanacearum RipTALs (de Lange et al., 2013).
The roles played by TALEs in contributing to plant disease are well-developed in many cases (reviewed in Boch et al., 2014) but almost nothing is known about the natural roles of RipTALs (de Lange et al., 2013) in bacterial wilt disease. The goal of this PhD project would be to study the contributions made by RipTALs to plant disease at the physiological and molecular level, with a view to combating this devastating plant pathogen.

Objectives:
- Investigate the contribution made by RipTALs to bacterial growth and plant disease in diverse host species.
- Use next-generation transcriptome sequencing (RNA-Seq) to isolate RipTAL target genes within the host.
- Elucidate the molecular mechanisms linking the induced target gene(s) to the observed growth/disease phenotypes.

Methods:
- Microbiological methods involved with the culturing and manipulation of R. solanacearum.
- Work with whole plants and plant cell protoplasts.
- RNA-seq.
- Molecular cloning.

Institute and team: The centre for molecular plant biology (ZMBP) is situated in a brand-new and well-equipped building in the Tübingen University science campus. Due to the common methods and organisms used within the ZMBP the environment is enriching and productive.
The Lahaye lab is made up of four PhD students, three Post-docs and two technicians at the moment. This allows for a lot of tight-knit collaboration within the group as well as a friendly atmosphere. English is the working language within the group and the whole ZMBP.

Your profile: Preference will be given to candidates with experience in molecular cloning and/or bacterial plant pathogen systems. An interest in bioinformatic analysis of next-generation sequencing data is desirable but not essential. A Masters degree is desirable but not essential.

Contact: If you are interested this job offer, please send an application via email to: [Email Address Removed]. More info on the ZMBP and the Lahaye group can be also found at our webpage: http://is.gd/w4I7BI