Effector Identification in the Lettuce Downy Mildew Bremia Lactucae by Massively Parallel Transcriptome Sequencing

摘要: Lettuce downy mildew (Bremia lactucae) is a rapidly adapting oomycete pathogen affecting commercial lettuce cultivation. Oomycetes are known to use diverse arsenal of secreted proteins (effectors) manipulate their hosts. Two classes effector be translocated by the host: RXLRs and Crinklers. To gain insight into repertoire effectors used B. lactucae its host, we performed massively parallel sequencing cDNA derived from spores infected (Lactuca sativa) seedlings. From over 2.3 million 454 GS FLX reads, 59 618 contigs were assembled representing both plant transcripts. Of these, 19 663 determined origin as they matched genome sequences (SOLiD) that obtained >270 reads spore-derived genomic DNA. After correction errors with SOLiD data, translation protein models filtering, 16 372 remained, 1023 which predicted secreted. This secretome included elicitins, necrosis ethylene-inducing peptide 1-like proteins, glucanase inhibitors lectins, was enriched in cysteine-rich proteins. Candidate host-translocated 78 RXLR features. In addition, found indications for an unknown number Crinkler-like sequences. Similarity clustering revealed additional candidates. We provide first look at transcriptome encoded arsenal.