The internal transcribed spacer （ITS） region （ITS1, ITS2 and 5.8S rDNA） of the nuclear ribosomal DNA （nrDNA） was amplified via the PCR method in seventeen different isolates of Phytophthora sojae using the commo...The internal transcribed spacer （ITS） region （ITS1, ITS2 and 5.8S rDNA） of the nuclear ribosomal DNA （nrDNA） was amplified via the PCR method in seventeen different isolates of Phytophthora sojae using the common primers of the ITS of fungi. Around 800 bp- 1,000 bp fragments were obtained based on the DL2000 marker and the sequences of the PCR products were tested. Taking isolate USA as outgroup, the phylogenetic tree was constructed by means of maximum parsimony analysis, and the genetic evolution among isolates was analyzed. The results showed that there is a great difference between the base constitution of ITS 1 and ITS2 among various isolates. The seventeen isolates are classified into three groups, and the isolates from the same region belong to the same group, which shows the variation in geography.展开更多
In many eukaryotic organisms, Cdcl4 phosphatase regulates multiple biological events during anaphase and is essential for mitosis. It has been shown that Cdcl4 is required for sporulation in the potato blight pathogen...In many eukaryotic organisms, Cdcl4 phosphatase regulates multiple biological events during anaphase and is essential for mitosis. It has been shown that Cdcl4 is required for sporulation in the potato blight pathogen Phytophthora infestans; howev- er, the role that the Cdcl4 homolog （PsCdcl4） plays in the soil-borne soybean root rot pathogen P. sojae remains ambiguous. PsCdc14 is highly expressed in spornlation, zoospore, and cyst life stages, but not in vegetative mycelia and infection stages, suggesting that it contributes to asexual reproduction and thus the spread of the disease. Double-stranded RNA （dsRNA） medi- ates gene silencing, a post-transcriptional and highly conserved process in eukaryotes, involving specific gene silencing through degradation of target mRNA. We combined in vitro dsRNA synthesis and a polyethylene glycol-mediated transfor- marion system to construct a dsRNA-mediated transient gene silencing system; and then performed a functional analysis of PsCdcl4 in P. sojae. PsCdc14 mRNA was dramatically reduced in transformants after protoplasts were exposed in in vitro synthesized PsCdc14 dsRNA, resulting in low sporangial production and abnormal development in P. sojae silencing lines. Furthermore, dsRNA-mediated transient gene silencing could enable elucidation of P. sojae rapid gene function, facilitating our understanding of the development and pathogenicity mechanisms of this oomycete fungus.展开更多
基金This work was supported by National Natural Science Fundation of China (No.30400285, 30671317), Postdoctoral Grant from Ag-riculture Sciences Academy of Heilongjiang Province (No. LRB06-010), China Postdoctoral Grant, Item for Teachers from Heilongjiang University (No. 140022), Young People’s Science Fund of Heilongjiang Province (No. QC06C012), 973(No. 2004CB117203-4), the Opening Fund of Key Opening Laboratory of Physiology and Ecology of Crop in Cold Terra of Agriculture Ministry "the Cloning and Mapping of cDNA Sequence from Related Gene Resistant to Phytophthora sojae and International Tech-nology Cooperation Item (No. 2005DFA30340).
文摘The internal transcribed spacer （ITS） region （ITS1, ITS2 and 5.8S rDNA） of the nuclear ribosomal DNA （nrDNA） was amplified via the PCR method in seventeen different isolates of Phytophthora sojae using the common primers of the ITS of fungi. Around 800 bp- 1,000 bp fragments were obtained based on the DL2000 marker and the sequences of the PCR products were tested. Taking isolate USA as outgroup, the phylogenetic tree was constructed by means of maximum parsimony analysis, and the genetic evolution among isolates was analyzed. The results showed that there is a great difference between the base constitution of ITS 1 and ITS2 among various isolates. The seventeen isolates are classified into three groups, and the isolates from the same region belong to the same group, which shows the variation in geography.
基金supported by the Special Fund for Agro-Scientific Research in the Public Interest (Grant No. 3-20) from the Chinese governmentthe Priority Academic Program Development for Jiangsu Higher Education Institutions
文摘In many eukaryotic organisms, Cdcl4 phosphatase regulates multiple biological events during anaphase and is essential for mitosis. It has been shown that Cdcl4 is required for sporulation in the potato blight pathogen Phytophthora infestans; howev- er, the role that the Cdcl4 homolog （PsCdcl4） plays in the soil-borne soybean root rot pathogen P. sojae remains ambiguous. PsCdc14 is highly expressed in spornlation, zoospore, and cyst life stages, but not in vegetative mycelia and infection stages, suggesting that it contributes to asexual reproduction and thus the spread of the disease. Double-stranded RNA （dsRNA） medi- ates gene silencing, a post-transcriptional and highly conserved process in eukaryotes, involving specific gene silencing through degradation of target mRNA. We combined in vitro dsRNA synthesis and a polyethylene glycol-mediated transfor- marion system to construct a dsRNA-mediated transient gene silencing system; and then performed a functional analysis of PsCdcl4 in P. sojae. PsCdc14 mRNA was dramatically reduced in transformants after protoplasts were exposed in in vitro synthesized PsCdc14 dsRNA, resulting in low sporangial production and abnormal development in P. sojae silencing lines. Furthermore, dsRNA-mediated transient gene silencing could enable elucidation of P. sojae rapid gene function, facilitating our understanding of the development and pathogenicity mechanisms of this oomycete fungus.
