Identification of tolerance factors in Arabidopsis for cyst nematode infection
Nematodes are a worldwide pest to a whole range of crops. There are several groups of plant parasitic nematodes, but the most damaging are the root-knot nematode Meloidogyne spp., and the cyst nematodes Heterodera and Globodera spp.. During their migration through the root cyst nematodes cause extensive damage, often leading to necrosis. Plants evolved an immune system which is based on the specific recognition of proteins and molecular patters by extracellular receptors and resistance genes present in the cytoplasm. Often does this recognition lead to programmed cell death. Both, the migration and immune response have a negative impact on the fitness of the plant. Currently, the strategy of the breeding companies is ‘breeding for resistance’. However, the use of resistance genes positively selects for more virulent populations. For instance, recently a more virulent population of Globodera pallida was observed in the north-east of The Netherlands and Emsland (Germany). These findings suggest that we should change our strategy to a more durable one, like tolerance.
In my research project the focus is to identify candidate genes which code for tolerance and plasticity towards cyst nematodes. The idea of tolerance is the acceptance of the presence of pathogens without significant reduction in plant fitness and yield. By exploiting the genetic diversity of Arabidopsis thaliana we will try to identify regions in the genome that code for tolerance. So far, allelic variation in genetic loci, associated with tolerance, has thus far not been used to breed for cyst nematode tolerant crops.