21183405
not annotated - annotated - LINNAEUS only
Genomics of biotrophic, plant-infecting plasmodiophorids using in vitro dual cultures.
The plasmodiophorids are a phylogenetically distinct group of parasitic protists that infect plants and stramenopiles, causing several important agricultural diseases. Because of the obligate intracellular part of their lifecycle, none of the plasmodiophorids has been axenically cultured. Further, the molecular biology of the plasmodiophorids is poorly understood because pure cultures are not available from any species. We report on an in-vitro dual culture system of the plasmodiophorids Plasmodiophora brassicae and Spongospora subterranea with their respective plant hosts, Brassica rapa and Solanum tuberosum. We show that these plasmodiophorids are capable of initiating and maintaining stable, long-term plant cell callus cultures in the absence of exogenous plant growth regulators. We show that callus cultures harbouring S. subterranea provide an excellent starting material for gene discovery from this organism by constructing a pilot-scale DNA library. Bioinformatic analysis of the sequences established that almost all of the DNA clones from this library were from S. subterranea rather than the plant host. The Spongospora genome was found to be rich in retrotransposable elements, and Spongospora protein-coding genes were shown to contain introns. The sequence of a near full-length non-LTR retrotransposon was obtained, the first transposable element reported from a cercozoan protist.
Ann file
T1 Species 582 606 Plasmodiophora brassicae
N1 Reference T1 Taxonomy:37360
T2 Species 611 634 Spongospora subterranea
N2 Reference T2 Taxonomy:70186
T3 Species 670 683 Brassica rapa
N3 Reference T3 Taxonomy:3711
T4 Species 688 705 Solanum tuberosum
N4 Reference T4 Taxonomy:4113
T5 Species 923 937 S. subterranea
N5 Reference T5 Taxonomy:70186
T6 Species 1172 1186 S. subterranea
N6 Reference T6 Taxonomy:70186