The Role Of Autophagy On Leaf Rust Infection Induced Hypersensitive Cell Death In Wheat

Hypersensitive reaction(HR) is one of the important forms of plant resistance to pathogen, that is cell rapidly death near the pathogen infect parts and pathogen, forming necrotic lesion, which make the growth of pathogenic bacteria can not get the right environment and nutrition and death, in this case it has been confined to a certain range to be extended. At the same time, HR must pass a special control in a certain range of mechanism finely, so that the host damage control to a minimum. But so far this regulatory mechanism is not clear. Autophagy, refers to cells under the condition of nutrient deficiency or stress, through the degradation of cell senescence long-lived protein, damaged cell structures and organelles, for the reconstruction of the cells, regeneration and repair provide the necessary raw materials, make cell recycle and reuse come true, is a kind of important biological defense and protection mechanisms. Cell autophagy functions in plants are constantly being revealed, especially in the role of immune response, has attracted widespread attention. About the role of autophagy in HR there are two opposite points of view: cell autophagy protects cells from cell death and cell autophagy promotes cell death. The present data show that the two hypotheses are likely to be correct, depending on cell type, the kinds of stimulation and cell state of development. In Triticum aestivum resistance to Puccina recondita infection, also produces a large number of HR, is this process will be a autophagy be involved in? If autophagy is induced, what is its function? This study of Triticum aestivum- Puccina recondita interaction system as the research object, use of Triticum aestivum(Triticum aestivum L.) varieties Lovrin 10 and Puccina recondita physiological incompatibility combination consisting of 260, 165, and affinity, investigate autophagy in the role of Triticum aestivum resistance to Puccina recondita infection induced HR. By histological observation of ultrastructure with transmission electron microscopy(sem) observation, cells of HR is induced directly by the haustorial mother cells occurred after contact, and HR cell won’t spread to the surrounding, that means the HR is tightly controlled. Next focus on HR cells adjacent to the border between plasmodesmata on the cell wall, and through the living after the injection of callose synthesis inhibitor DGG observed changes in the HR area, results indicate that callose and plasmodesmata may not participate in HR cell and control signal of material transportation between adjacent cells. Then by selecting the autophagy is formed in theprocess of signature ATG6 detection of target genes, use of real-time quantitative PCR and protein immunoblot technique, respectively from the level of protein and RNA levels have verified the HR process involved in autophagy, use autophagy specificity of fluorescent staining combined with confocal laser scanning microscopy and transmission electron microscope, respectively under the lens(live), electron microscopy(sem) levels for different combinations of infested cells and the surrounding cells at different time point infect the autophagy has carried on the structure of the observation, the results showed that in HR cells(whether early or late,) can be observed that autophagy structure. In order to further study the function of autophagy, using virus induced gene silencing(VIGS) silence the key genes ATG6 autophagy formed, Puccina recondita induced HR extension. Autophagy was induced in HR early stage,and accelerate the process of HR by the way of the contents of the encapsulated cells to degrade. This research helps us better understand the role of autophagy in the plant immune response, to provide scientific theoretical basis for disease resistance breeding and the prevention and control strategies.