交变应力作用下烟草细胞热力学相行为的研究

研究了交变应力对烟草愈伤组织细胞的影响， 采用本实验室研制的强声波发生装置来产生交变应力场， 并利用差式扫描量热仪（ＤＳＣ） 研究了不同强度和频率的交变应力作用后烟草细胞热力学相行为的变化。研究结果表明：交变应力的影响与应力的频率和强度密切相关，一定频率和强度范围内的交变应力能使得植物细胞的相变温度有明显的降低， 而过高频率的应力刺激则会使细胞相变温度升高。细胞热力学相变反映了细胞壁膜的流动性，相变温度变低表明细胞壁膜的流动性增强， 这必然为细胞的生长和分裂提供了便利的条件。 因此， 对于从细胞和分子水平研究交变应力对植物生长、发育的影响及其作用机理是一个很有意义的尝试

THE EFFECTS OF ALTERNATIVE STRESS ONTHE THERMODYMICAL PROPERTIES OF CULTURED TOBACCO CELLS

The effects of alternative stress on cultured tobacco cells were studied. The field of alternative stress was generated through a strong sound field system set up in our lab, and the thermodynamic properties of cells were studied by Differential Scanning Calorimeter (DSC). We found that the effects of stress on cells depended greatly on the intensity and frequency of stress. In a certain range of intensity and frequency, the stress decreased the phase transition temperature significantly, while the stress with higher frequency or intensity may cause the phase transition temperature to increase. Thermodynamic phase transition denotes the fluidity of cell wall and membrane. The decrease of phase transition temperature, as well as the enhancement of the fluidity of cell wall and membrane, make the cell to growth and division faster and easier. The enhancement of cell wall fluidity might be one of the mechanism of the promotion of plant growth by alternative stress.