[Cloning and expression of a class II chitin synthase gene PstChs II from the rust fungus Puccinia striiformis]

Abstract

Objective: To clone the chitin synthase gene PstChs II from Puccinia striiformis and to analyze its expression pattern.

Methods: We isolated the cDNA and genomic DNA of PstChs II via RT-PCR and PCR,analyzed the sequences with different bioinformatic tools, characterized the gene expression pattern via real-time PCR.

Results: The coding region of PstChs II (Genbank accession no: GQ329851), interrupted by 15 introns, corresponded to a 2727 bp open reading frame encoding 908 amino acids. PstChs II showed a highest 94% similarity to PgtChs II from Puccinia graminis. PstChs II had 7 transmembrance regions and several conserved chitin synthase domains and motifs such as "QXRRW", "GXGPL" and "DXD". PstChs II belonged to the class II sub-family and had a closer phylogenetic relationship to its homologs from basidiomycetes than those from ascomycetes. PstChs II expression level increased by 10-fold at the urediospore germination stage.

Conclusion: PstChs II might be involved in the cell wall synthesis during the germ tube elongation process. The cloning and expression analysis of PstChs II served as a good foundation for further analyzing the role of this gene in the pathogenesis process.