不同活力黄瓜种子萌发期间多胺含量的变化

黄瓜种子中存在着腐胺、亚精胺和精胺三种内源多胺.高活力种子在萌发初期,精胺、亚精胺和腐胺含量逐渐增加,在12h时达到最大值、而低活力种子精胺、亚精胺和腐胺含量呈现下降.同时,腐胺与亚精胺和精胺含量之比,在高活力和低活力的种子均随着种子的萌发而逐渐下降,而精胺与亚精胺含量之比在萌发初期均呈下降的趋势,但萌发12h后,高活力种子其比值即转变为迅速的增加,而低活力种子至18h后才可见比值的缓慢增加.在种子萌发过程中,蛋白质、RNA和DNA含量的变化模式与精胺和亚精胺含量的变化极相似.本文认为,种子萌发的能力与内源多胺含量变化有关,可能取决于多胺间的相对比值.

Changes in polyamine concentration during germination of cucumber seeds with various vigours.

Putrescine(PUT) ,spermidine(SPD) and spermine(SPM) were present in cucumber seeds. During germination, polyamine content and its alteration were different in seeds of various vigour. In high-vigour seeds, the level of SPM, SPD and PUT increased progressively, being maximun at 12 hours of germination, but in low-vigour seeds, SPM, SPD and PUT gradually decreased. In general, the contents of SPM and SPD were constantly higier in high-vigour seeds than that in low-vigour ones. Because the change of ratio of concentrations of three polyamines was different, the ratio of PUT to SPD and SPM declined during germination, but the decrease in the ratio was faster in high-vigour seeds than that in low ones. The ratio of SPM to SPD gradually reduced in the initial hour of grtmination, then, it began increasing after 12 hours of germination in high-vigour seeds, but after 18 hours in low-vigour seeds. The contents of protein, RNA and DNA showed a pattern similar to the SPD and SPM. Results of the turnover experiments suggested that ability to seed germination might be related to the contents of polyamines, but it might depend on their ratio.