Tobacco Suspension Culture Induced By Mechanical Stimulation Of Programmed Cell Death Process And Its Relationship With H <sub> 2 </ Sub> The O <sub> 2 </ Sub> And Ca ~ (2 +)-cam

Using two series of transgenic tobacco cell expressing cytosolic CaM/ CaMBP as experimental materials, we studied the effect of mechanical stimulation on programmed cell death and H₂O₂ generation.The dissertation is divided into three parts:Part Ⅰ We investigated the effects of different intensity of mechanical stimulation on the development of programmed cell death. In this part, a series of distinct programmed cell death characteristics were observed when the cells were induced by different intensity of mechanical stimulation and the DNA ladders consisting of several bands also showed that the cells genome DNA was degraded, indicating that the cells were indeed induced into programmed cell death and an oxidative burst during the mechanical stimulation.Part Ⅱ Using the expressing cytoplasmic CaM/CaMBP transgenic tobacco lines(H3-19) as experimental materials, We detected the impact of H₂O₂ on development of programmed cell death, the results showed that exogenous H₂O₂ pretreatment also induced the progress of programmed cell death.Part Ⅲ It has studied that possible function of Ca²⁺-CaM in the PCD process . The result showed the change of CaM activity during mechanical stimulation and endogenous H₂O₂ pretreatment. Raised Ca²⁺ and lowered Ca²⁺ inhibited H₂O₂ production during mechanical stimulation. The result indicated that mechanical stimulation induced-H₂O₂ level was suppressed in the condition of raised Ca²⁺ and lowered Ca²⁺ content.