Function Analysis Of PsPITP1in Phytophthora Sojae

Phytophthora sojae is the casual agent of damping off of the seedlings and root rot disease of soybean. Since was first discovered in the United States in1948, the disease tendency to expand from the major producing areas to other areas in the world.It is becoming one of the major diseases in production of soybean in the world,and millions of dollars are lost annually. Therefore, It is particularly critical to research the P. sojae infection and pathogenic mechanisms.In recent years, with the rapid development of molecular biology and bioinformatics, oomycetes genetic transformation technology continues to mature and improve, especially after the completion of the sequencing of the genome of P.sojae and several other Phytophthora species, The pathogenic mechanism of oomycete has made great progress because of the effectors,This experiment will applied RNAi technology to the study of function analysis of PITP1in P. sojae.Bioinformatics and transcriptional of PsPITPl in P.sojae.PITP is ubiquitous in eukaryotic cells,It has the capable of binding and exchanging with phosphatidyl inositol (phosphatidylinositol, PI) or phosphatidyl choline (phosphatidylcholine, PC)and promoting the lipid molecules transfer among membrane. PITP has important implications in transport and metabolism of lipids between the components of the intracellular membranes, physiological and biochemical processes of the formation and transport of secretory vesicles, regulation of phospholipase C (phospholipase, PLC) signal transduction. In this study, bioinformatics methods was used to dig out a PITP protein from P.sojae genome database named PsPITPl, by homology with other eukaryotes, we found it was highly conserved.In P. sojae,the transcription profile of PsPITP1was also performed by qRT-PCR.we found an upregulated in the infection stage,and we presumably PsPITPl may involved in the infection process.PsPITP1is involved in growing development and pathogenicity in P.sojae.Expression of PITP1was silenced by the stable transformation system in P.sojae. The growth rate of the silenced mutants were reduced, cyst germination and the formation of lateral branches were increased significantly,resulting in the inability of infecting soybean in mutants. Silenced mutants can not form infestation hyphae, and the host cell around infection orifice were necrosis.PsPITP1is involved in the regulation of excretion pathways and host defense responses.We found the secretion of extracellular laccase was affected, SDS-PAGE analysis showed the secretion of extracellular proteins was also affected in the silenced mutant. Callose and reactive oxygen staining analysis found that the callose and reactive oxygen species accumulation of Hefeng47, inoculated by silenced mutant, are significantly more than wild-type. In Hefeng47that inoculated mutant strains show a up-regulation of PR1、 PR10,Which is testify as defense-related genes that in salicylic acid and jasmonic acid pathway.