The clubroot disease is caused by the obligate biotrophic protist
Plasmodiophora brassicae and is one of the most damaging for the family of Brassicaceae. Since many economically important crops belong to this plant
family, the understanding of mechanisms how the disease is developing, are of high importance. Glucosinolates, a group of
secondary plant products in the family of Brassicaceae, have long been associated with clubroot disease symptoms. Measurements
showed that several glucosinolates are induced in root galls. While aliphatic glucosinolates are regarded as defense compounds,
analysis of
Brassica cultivars as well as
Arabidopsis thaliana mutants provided correlative evidence between disease severity and indole glucosinolate content. The latter have been discussed
as precursors for auxin biosynthesis. Since high auxin levels are associated with large root galls, indole glucosinolates
could contribute directly or indirectly to the extent of disease development. Transcriptome and proteome experiments have
revealed evidence for the involvement of genes from the glucosinolate and auxin pathway in gall formation. These data have
been complemented by expression and mutant analysis. It can be concluded that regulation of glucosinolate and IAA biosynthesis
might differ in
Brassica and
Arabidopsis.
Keywords Auxin - Brassicaceae - Clubroot disease - Glucosinolates -
Plasmodiophora brassicae