Shifts in plant gene expression and corresponding phloem sap components during trilateral interaction of barley (Hordeum vulgare), aphid species (Rhopalosiphum padi) and the aphid-transmitted Barley Yellow Dwarf Virus (BYDV)

• Applicants: Professor Dr. Aart J.E. van Bel; Dr. Carola Wagner
• Subject Area: Plant Breeding and Plant Pathology
• Term: from 2007 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 34527299

The aphid-transmitted barley yellow dwarf (BYDV) luteovirus as well as the aphid-BYDV-interaction are both well described. The aphid-host and BYDV-host interactions in this tripartite relationship should be investigated before successful strategies against BYDV can be developed. The focus of this research is on the phloem: (1) aphids exclusively feed on the phloem, (2) BYDV propagation and transport is limited to the phloem, and (3) systemic responses to infestation and infection may be translocated via the sieve tubes. Logically, genes involved in barley tolerance against aphid infestation and BYDV infection are expressed in the phloem and some of their products translocated via sieve tubes. Gene and protein expression profiling are envisaged to detect local and systemic responses of aphid- and BYDV-tolerant barley cultivars. For that purpose, microarray hybridisation of leaf tissues and RNA and protein analysis of phloem exudates will be employed to identify shifts in gene and protein expression levels. Once candidate genes and proteins will have been identified, expression of the genes engaged in local resp. systemic response will be investigated by quantitative Real-Time-PCR. Subsequently, expression in local and systemic sites (phloem parenchyma, companion cells, sieve elements) will be compared. Finally, candidate genes for BYDV-tolerance will be mapped to detect co-localisation with known genetic loci (QTL) related to BYDV-tolerance. Expectedly, this study will provide a better understanding of the host response to aphid-infestation and infection by aphid-transmitted BYDV, in particular, with regard to the phloem-translocated signals of tolerant vs. susceptible host genotypes.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Wolfgang Friedt