松树种子萌发过程中苯丙氨酸解氨酶的活力

THE ACTIVITIES OF PHENYLALANINE AMMONIALYASE DURING THE GERMINATION OF PINE SEEDS

以黄山松、马尾松、赤松、黑松种子为供试材料,从它们吸胀萌发直至子叶伸展脱壳的过程(20～21 d)中,分阶段分别测定体内苯丙氨酸僻氨酶(PAL)的活力。结果表明,裸子植物种子萌发过程中也有PAL存在。若以鲜重为单位计算,PAL在此过程中的活性变化动态呈抛物线形式,与一年生草本作物相似;但若以蛋白氮计算,变化趋势表现为线性上升,与一年生草本作物(仍为抛物线)不同。不同树种的PAL活力大小与其生长快慢及木质化程度高低的顺序相同,均为黄山松、马尾松>赤松、黑松,说明其间有一定的关联。用亚胺环已酮(CHM)处理萌发材料时,表现的PAL活力比不处理的提高几倍,说明裸子植物与一年生草本作物一样,萌发幼体本身也有PAL内源抑制物质存在。

The activity of phenylalanine ammonialyase (PAL)was determined periodically during the germinating process of seeds (20-21 d, from imbibition to emergence of cotyledon) of Taiwan pine, Masson' s pine, Japanese red pine and Japanese black pine respectively. It turned out that PAL also existed during the germination of gymnospermous seeds as well as those of angiosperm. In the case of calculation with fresh weight, all the dynamics of PAL activity in the four species appeared to be the parabola, which were similar to those of annual herbaceous crops; whereas in the case of calculation with proteinous N, all the dynamics displayed positive linear character, being different from the annual herbaceous crops which were still in parabola shape. Sequence of PAL activity from various species was similar to that of their growth rate and lignifying degree, i. e. Taiwan pine, Masson' s pine > Japanese red pine, Japanese black pine, which indicated that there was a certain connection between them. When treating the germinating materials with cycloheximide (CHM), their PAL activity increased by several times, which showed that as the same of annual herbaceous crops, the endogenous inhibiting substance for PAL also existed in the germination of gymnosperm during the germination of their seeds.