Some Gene Expressions Of A Aigeiros Host Responsive To Marssonina Brunnea Two Forma Specialis Infection And Endophytic Fungi In Leaves

Two formae specials of Marssonina brunnea in Populus genus cannot be distinguished easily based on their morphologies and some nucleic acid molecular sequence marks. We study host pathogen in the infection process, the role of the mechanism of host, and analysis of the two formae speciales differences. Meanwhile endophytic fungal species poplar leaves on investigation, and analysis the relationship between pathogens. The application of new techniques for the identification of pathogens and their relationship with the host research interaction provides a new direction.This study collected samples of pathogenic material and health blade material. Tissue isolated strains of pathogens and endogenous, Total DNA as a template for PCR amplification on their ITS sequences. We applied combination of Marssonina sp. ribosomal internal transcribed spacer sequence for building the phylogenetic tree and ITS2 secondary structure to discriminate them. The use of in vitro leaves inoculated with pathogens spores, selected virulent formae speciales. Then screened strains were inoculated into the populus leaves of potted seedlings. By fluorescence microscopy strain spores infect leaves the process. Elected spores infect leaves time node. Application of Real-time PCR analysis detected several time nodes the expression of the host gene.The result show:(1)Endophytic fungi isolated mainly from 37 genera 257 strains, and advantages flora are Alternaria, Pseudocercospora, Botryosphaeria, Phaeosphaeria. While filtering out two strains of M. brunnea inhibition.(2)The pathogen spore had a typical morphology in leaves on hosts in the field within a formae speciale,but on the culture medium spore were quite different in morphology. We can’t effectively distinguish two formae speciales on the basis of the traditional number of germ tube germination. Three kinds of ITS sequences phylogenetic trees showed that there were three speicies in Marssonina genus. But reference ITS sequences with a formae specials from M. brunnea can’t be accurately located into other the same formae special with other strains. With the ITS2 secondary structure prediction model, it was found that Marssonina ITS2 secondary structure were identical not in the three species, M. rosae, M. coronariae, and two formae speciales of M. brunnea. But the ITS2 secondary structures have multiple bases sites different among the three species. With comparative analysis of ITS2 secondary structures, the Marssonina have obvious difference inside genus, and there are also have compensatory base changes within formae speciales. Application ITS2 secondary structures combined with phylogenetic trees can be more effective molecular characterizations to distinguish the two formae speciales in M. brunnea.(3)The Spores of two formae speciales in M. brunnea at three time points after inoculation 2h, 24 h, 96 h respectively spores just germinated, grow appressorium, produce fresh mycelium. The results of Real-time PCR show: PR5 target gene in these three nodes are upregulated. PR10 in the two samples showed increased rapidly after vaccination 2h expression, then decreases. NPR1 have a small volume of upregulated, 24 h downregulated, 96 h upregulated to 2h expression levels in H sample. Compared with the expression of B sample increased gradually raised after vaccination. PtrWRKY89 and PtrLAR3 were all upregulatedode. The three host gene expression differences in infection process in the two forma specialis.