Differential gene behavior in resistant potato plants challenged with late blight disease

Late blight caused by the fungus Phytophthora infestans, is one of the most important diseases of potato (Solanum tuberosum L.) crop worldwide. However, in spite of its importance, understanding of the pathosystems mediating potato infection by this fungus is still limited. Therefore, to better understand the defense responses initiated by potato resistant plants challenged with P. infestans, expression of six well known defense-related genes were monitored at early four-time points of infection. Time-course experiments revealed notable differences in gene expression patterns during potato-pathogen interaction as compared to the non-infected control. It is noteworthy that both PR3 and StSYR1 have higher constitutive expressions with 6.1 and 8.1 folds, respectively, at 48 and 72 hours post inoculation (hpi) period. It was clear that their expressions were higher at the necrotrophic stage compared with the biotrophic one. According to findings, our data can provide an insight into the signaling pathways that accounts for conventional gene expression changes elicited during potato-P. infestans interactions

Transcriptome Analysis of the Barley-Rhynchosporium secalis Interaction

Leaf scald caused by the infection of Rhynchosporium secalis, is a worldwide crop disease resulting in significant loss of barley yield. In this study, a systematic sequencing of expressed sequence tags (ESTs) was chosen to obtain a global picture of the assembly of genes involved in pathogenesis. To identify a large number of plant ESTs, which are induced at different time points, an amplified fragment length polymorphism (AFLP) display of complementary DNA (cDNA) was utilized. Transcriptional changes of 140 ESTs were observed, of which 19 have no previously described function. Functional annotation of the transcripts revealed a variety of infection-induced host genes encoding classical pathogenesis-related (PR) or genes that play a role in the signal transduction pathway. The expression analyses by a semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) revealed that Rar1 and Rpg4 are defense inducible genes, and were consistent with the cDNA-AFLP data in their expression patterns. Hence, the here presented transcriptomic approach provides novel global catalogue of genes not currently represented in the EST databases