Project description:Transcription profiling of the DSF regulon in Xanthomonas oryzae pv. oryzae (Xoo) using wild type and the rpfF mutant. Cell-cell signaling mediated by the quorum sensing molecule known as Diffusible Signaling factor (DSF) is required for virulence of Xanthomonas group of plant pathogens. DSF in different Xanthomonas and the closely related plant pathogen Xylella fastidiosa regulates diverse traits in a strain specific manner. The transcriptional profiling performed in this study is to elucidate the traits regulated by DSF from the Indian isolate of Xanthomonas oryzae pv. oryzae, which exhibits traits very different from other Xanthomonas group of plant pathogen. In this study, transcription analysis was done between a wild type Xanthomonas oryzae pv. oryzae strain and an isogenic strain that has a mutation in the DSF biosynthetic gene rpfF.
Project description:Fungal endo-M-NM-2-mannanases (M-NM-2-mannanases) are widely used as industrial enzymes; however, no transcriptional regulator of M-NM-2-mannanases has been identified in fungi or other eukaryotic cells to date. To identify a transcriptional regulator of M-NM-2-mannanases in Aspergillus oryzae, a gene-disruptant library of transcriptional regulators was screened for mutants exhibiting reduced M-NM-2-mannanase activity by using konjac glucomannan as the substrate, and ManR, a Zn(II)2Cys6 type DNA binding protein was identified. Moreover, a manR-overexpressing strain showed significantly increased M-NM-2-mannanase activity. DNA microarray analysis of the manR-disruptant strain and the manR-overexpressing strain further indicated that when konjac glucomannan is used as the carbon source, ManR positively regulates the gene expression of not only M-NM-2-mannanase, but also the enzymes involved in the degradation of galactomannans and glucomannans such as M-NM-1-galactosidase, M-NM-2-mannosidase, acetylmannan esterase, and M-NM-2-glucosidase. Therefore, we conclude that ManR is a positive regulator of the M-NM-2-mannan utilization system in A. oryzae. manR disruptant, manR-overexpressing strain and A. oryzae RkuptrP2-1M-bM-^HM-^FAF/P (derivative of A. oryzae RIB40) were cultivated in minimal medium containing 1% konjac glucomannan as the sole carbon source. After 6 h cultivation, total RNAs from the mycelia were extracted, and DNA microarray analysis was carried out. The analysis of manR disruptant was conducted with 4 biological replications, the analysis of manR overexpressing strain was conducted with 3 biological replications.
Project description:In this study, we focused on chemically defined inducers or substrates to drive expression of cellulases, hemicellulases and accessory enzymes in the model filamentous fungus Aspergillus oryzae. Cellohexaose (O-CHE), mannohexaose (O-MHE), xylopentaose (O-XPE), arabinoheptaose (O-AHP), 1,3:1,4-M-NM-2-glucohexaose (O-BGHEXA), 63-M-NM-1-D-glucosyl-maltotriosyl-maltotriose (O-GMH), 61-M-NM-1-D-galactosyl-mannotriose (O-GM3), xyloglucan (X3Glc4-borohydride reduced; O-X3G4R), turanose (TYR) and sophorose (SOP) were used to induce the plant polysaccharide degradation machinery of A. oryzae. The strain used in this study was the A. oryzae sequenced strain RIB40, obtained from IBT culture collection at Technical University of Denmark. To obtain a global view of the A. oryzae transcriptome activated for plant biomass conversion, mRNA from growth after 2 h on 10 different carbohydrate active enzyme inducers (di- and M-bM-^@M-^Soligo saccharides) was subjected to custom-designed Agilent microarray analysis.