Exploiting genetic variability of resistance genes in major European food legumes to improve varieties for sustainable agriculture

Abstract

LEGRESIST is a consortium of 10 leading European research centers and companies for legume breeding and molecular biology, and 2 leading technology providers. In Europe, agronomical, economical and ecological benefits of legumes for the entire agro-system are notoriously under-exploited due to their unstable yield caused by the plants susceptibility to a wide range of pathogens. Despite considerable investment and progress in use of molecular tools for resistance breeding, application of Marker-Assisted Selection and Marker-Assisted Pyramiding of resistance genes to obtain durable resistance is still hampered by non-sufficient knowledge of allelic diversity in resistance genes and the lack of insight into plant-pathogen interactions responsible for the hard-to-handle quantitative nature of resistance. Moreover, affordable, modern tools for advanced resistance breeding are missing. Therefore, LEGRESIST aims at i) exploiting genetic diversity of resistance genes on the level of Single Nucleotide Polymorphisms (SNPs) for genetic mapping of all expressed resistance genes in major crop legumes, ii) understanding quantitative resistance through characterization of the interacting transcriptomes of plants and their pathogens by SuperSAGE analysis and iii) mapping of expression(e)QTL underlying quantitative resistance. The project delivers polydimensional SNP-Arrays for rapid and cost efficient mapping of resistance genes and legume-specific Biotic-Stress-Arrays for eQTL mapping. Up to now, SuperSAGE revealed the expression of more then 1.4 million 26bp long SuperTags representing the same number of transcripts from the legumes. Of these, more than 1500 were significantly differentially expressed in response of the legumes’ stems and leaves to infection with their major, airborne fungal pathogens. These data provided the base for the design of the Biotic-Stress-Micro-Arrays currently under investigation. The search for SNPs in potential resistance genes delivered large numbers of SNP and Indel polymorphisms that can be exploited for resistance breeding. Applying these modern tools, LEGRESIST will produce the most advanced expression maps for all major crop legumes. Further, exploiting synteny between the crops and the model legume Medicago truncatula, the project will result in the first comparative biotic stress map of the legumes. Such innovative tools will enable breeders to provide durable resistant, non-GMO legumes for the Multibillion Euro market for vegetable protein currently served by soybean imports. That way, novel plant biotechnology will prove its benefits likewise for European economy and ecology.