Abstract
About 1% of angiosperms are adapted to a parasitic life style. Parasitic plants penetrate host tissues and rob them of water and nutrients. The obligate parasites Striga and Orobanche parasitize agriculturally important crops and cause devastating damages in worldwide. Understanding of molecular basis of plant parasitism will contribute to finding the way to eradicate such agricultural pest species.
Phtheirospermum japonicum is a facultative parasitic plant naturally grown in Japan and belongs to Orobanchaceae same as Striga and Orobanche. Facultative parasites can grow autotrophically and therefore will be ideal as experimental materials. We carried out a large-scale transcriptome analysis of P. japonicum using next-generation sequencing. We extracted RNAs from autotrophycally grown P. japonicum roots and rice-parasitizing P. japonicum, and analysed them with Roche 454 FLX and illumina Hi-seq2000 sequencer. The sequences were assembled into approximately 50,000 contigs. Short-reads from illumina sequencing were mapped on those contigs. Our data suggest that hydrolase enzymes such as proteases are highly expressed in parasitic tissues.