Transcriptomic Analysis Of Formation Of Constricting Rings Of The Nematode-Tapping Fungus Drechslerella Brochopaga

In this study,RNA-seq technology was used to analyze the expression of the nematode-trapping fungus Drechslerella brochopaga at three time points during the formation of constricting rings on inuction of nematode extracts.Analysis of differentially expressed genes(DEGs)revealed the up-regulated gene expression related to cell division,cell elongation,cell wall synthesis,subtilis protease and genes involved in transcription factors which may play an important role in the formation of trapping devices.The functional annotations and analysis,including GO annotation,KEGG annotation,enrichment analysis and search against various functional databases(KOG,COG,PHI,CaZyme and Merops),suggests that the formation process of trapping devices were related to cell process,genetic information process,oxidation-reduction process and catalytic activity.After induced by nematode extracts,transcription factors regulate the gene expression of cell division,cell elongation,cell wall synthesis related genes such as WSC-containing domain gene and SUR7 domain-containing gene and some genes in MAPK pathway such as ste20 express differentially controlling constricting rings formation.Besides,chitinase(db0206152),serine protease(db0200775,db0202051,db0201690,db0207140,db0202319),mechanosensitive ion channel MscS-like protein(db0203931)showed up-regulation.With the presence of the mechanically stimulation of nematode,the mechanosensitive ion channel of constricting rings responds accordingly.G-protein related genes activated multiple cascadeing pathways including MAPK pathway.The expansion of three-cell leads to closure of lumen,and chitinase and serine protease make concerted effort to capture nematodes.Our results suggetes that not only the mechanical force,but also other genes such as chitinase and serine proteases make great contributes to the success of constricting rings to destroy the cuticles of nematodes.In this study we have identified the differentially expressed genes in the formation of constricting rings of Drechslerella brochopaga.Functional analysis of these genes highlights their roles in the formation of trapping devices and the expansion of the three-cells,which provides clues for further studies to reveal the underlying mechanisms of trap formation of nematode-trapping fungi.