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Embryogenic plant suspension cell line is not only the important sources of protoplasts, but also it can also be used as receptor of gene transfer plants. It has a great application in the plant tissue culture. Therefore, studying the preservation of rice embryogenic suspension cells and the progress cell death in the long-term culture has the great significance.In the study, we set up a method of preservation the rice embryogenic suspension cell line by optimizating the main parameters of the encapsulation-dehydration: embryogenic suspension cells were pre-cultured in increased concentration with the 0.25,0.5,0.75 repectively and 1 mol·L-1 sucrose AA liquid medium in 2d. The mixture contains 8%(w/v) alginate calcium,1 mol·L-1 sucrose,2 mol·L-1 of glycerol, the secondary pre-culture is cultured in 1 mol·L-1 sucrose AA liquid medium in 3d, dehydration with 120min, liquid nitrogen freezing, thawing, the frozen cells was resumed in the AA solid medium within 2.5 g·L-1 AC (0.8% agar). The resumption cultured cells, which can grow callus but growth slowing, have some of the lag period of 5 d. This method can be used not only in the preservation of rice embryogenic suspension cell line, but also can be used on screening high-quality embryonic cells. We successly used the encapsulation-dehydration preservation rice suspension cells for the first time, and extense the time of preserve the cells.On the basis, we have studied the relationship between the rice embryogenic suspension cell lines both inside and outside of the total phenol content and programmed cell death. In Plants, when the cells hurt, phenol and polyphenol oxidase would have been separated from, have an opportunity to contact, and in the role of oxygen, will generate the quinone, which result in the browning aging and death of cells. First, we use paracetamol as inducers by adding different concentrations of catechol processing exogenous, which simulate biological accumulation of polyphenols in vivo. After different treatment of concentrations and times, we found that cell death rate is rising, the endogenous total phenol content, H2O2, MDA, content all increased, as well as antioxidant enzyme is activated. DAPI and AO/EB staining showed significant apoptosis, nuclear cohesion and cell shrinkage. Analysis of H2O2、O2·-、MDA may be the main reason leading to cell death. We can surmise that cells occurred programmed cell death in the 2mmol-5mmol o-dihydroxybenzene concentration, a higher cell death in lOmmol o-dihydroxybenzene in the 48h processing, following the slightly injury of cells under the 2mmol, strong resistance. Cell browning and death did not appear immediately, which indicate that the cells have some degree of tolerance. The harm of Phenol is a process of accumulation with time. Above results provided strong evidence to understanding of browning in tissue culture, as well as the mechanism of senescence in cell culture.
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