Domain Characterization And Interacting Protein Screening Of Hypersensitive Cell Death-Inducer From Magnaporthe Oryzae

Cause rice blast by the filamentous fungus Magnaporthe oryzae, is the most serious disease of cultivated rice, which can lead to annual rice production losses around the world with the worth of over one billion rice production in China and the world on one of the most important diseases. To control rice blast, we should deepen the interaction between rice and rice blast fungus understanding of regulatory mechanisms. The rice blast fungus, elicitor of the screening secreted proteins and functions of such proteins for the study described the role of rice blast elicitor molecular mechanisms in the host cell laid the foundation for further study, anti-damage resistance to rice blast is also important.In the rice secreted protein contains including the elicitors induce HR of plant. Defense responses in inducing plants, the pathogen secreted elicitor as a kind of important signaling molecules into plant cell protoplast membrane which include highly specific protein receptor binding affinity, so that the resistance-related gene expression, in order to initiate a series of plant defensive responses. In previous study, we screened2effectors partl₅248and part2₄474from M. oryzae which could induce HR in tabcco. In this study we functional analysis the domains of these2elicitors on the induction of cell death. To clarify the relationship between the molecular structure of the elicitors and their effect on HR, we first mutate the elicitor and use the PVX virus system to inject the Nicotiana tabacum. The results showed that deletion the N-terminal of partl₅248can not induce the cell death on Nicotiana tabacum and20aa and25aa is essential for cell death. We further checked the expression level of several genes on ET, JA and SA disease-resistant pathways in the Nicotiana tabacum treated with partl₅248and mutants, the results showed that partl₅248induced genes expression in JA signaling pathways, invinvolved in plant resistance to produce, but△partl₅24820mutants （not cause HR） induced related genes expression in SA signaling pathway. Additionally, we use partl₅248and part2₄474as bait protein and screened a Nicotiana tabacum Fdn-1in cDNA library by Yeast two hybridization. Fdn-1is a homolog of Nicotiana tabacum and showed94%amino acid identity. Another interacting gene is NTH201, a member of KNOTTED1-like transcription factor family protein. NTH201showed95%amino acid identity to Nicotiana tabacum NTH201and known as a virus infection proliferation gene.Magnaporthe oryzae secreted proteins partl₅248and part2₄474can induced the cell death in Nicotiana tabacum,but in the Magnaporthe oryzae these two genes were been knockouted and overexpressioned. In the pathogenicity tests, compare with Guy11, knockout mutant of part1₅248and part2₄474showed no difference. part1₅248over-expression of rice mutants have a certain reduction in pathogenicity, and part2₄474overexpression of mutant compare with wild-type pathogenicity has no difference. In summary, partl₅248not only in the non-host plant defense responses can induce defense response, and participating pathopoiesia in the rice that can also decrease pathogenicity of Magnaporthe oryzae.