Project description:In this study we identified the L-arabinose-responsive regulator of Pyricularia oryzae that regulates L-arabinose release and catabolism. Previously we identified the Zn2Cys6 transcription factor (TF) AraR that has this role in the Trichocomaceae family (Eurotiales), but is absent in other fungi. Candidate Zn2Cys6 TF genes were selected according to their transcript profiles on L-arabinose. Deletion mutants of these genes were screened for their growth phenotype on L-arabinose. One mutant, named Δara1, was further analyzed. Our analysis demonstrated that Ara1 from P. oryzae is the functional homolog of AraR from A. niger, while sequence analysis did not reveal significant homology between them.
Project description:Rice blast caused by Magnaporthe oryzae is the most devastating disease of cultivated rice. Several protein kinase cascades have been known to be essential to pathogenesis or important for response to stress, mycelial growth and conidiation in M. oryzae. However, phosphoproteins and their phosphorylation sites (p-sites) in this important fungal pathogen remain largely to be identified. In this study, 8087 phosphopeptides corresponding to 9825 p-sites from 1147 phosphoproteins were identified in mycelia of M. oryzae under a false discovery rate of < 0.55% at the peptide level. Notably, 33 previously reported pathogenesis-related proteins were included in the phosphoproteins at the mascot delta score 10. Further analyses of 581 motif-containing phosphoproteins that met more stringent criteria revealed that the phosphoproteins shared 19 distinct phosphorylation motifs, including the motif RxxpSP that was newly identified in this study but is widely distributed in diverse organisms. These phosphoproteins were mapped into 81 biological pathways. A total of 82 acidic motif-containing phosphoproteins were identified. Surprisingly, none of them except one were mapped to any of the metabolic pathways. Furthermore, a prediction disclosed a total of 174 kinase-substrate specific interactions in mycelia of M. oryzae. This study also detected phosphorylation of the tyrosine phosphatase Pmp1 and 7 other proteins upstream of Pmk1, but not Pmk1 and its downstream transcription factors. These results prompted a necessary revision of Pmk1 MAPK cascade, in which dephosphorylation of Pmk1 by Pmp1 in mycelia may block the activation of downstream targets.
Project description:Genetic studies have shown essential functions of N-glycosylation during infection of the plant pathogenic fungi, however, systematic roles of N-glycosylation in fungi is still largely unknown. Biological analysis demonstrated N-glycosylated proteins were widely present at different development stages of Magnaporthe oryzae and especially strong in the appressorium and invasive hypha.A large-scale quantitative proteomics analysis was then performed to explore the roles of N-glycosylation in M. oryzae.
Project description:To study the effect of plant metabolites on M. oryzae, we selected salicylic acid (SA), abscisic acid (ABA), and sakuranetin to treat M. oryzae grown on the medium with the concentration of 100μM. After 10 days' treatment, the total RNA were extracted and detected the transcriptome.