赤豆种子萌发中幼苗酰脲含量及尿囊素酶活力变化动态

VARIATION IN THE SEEDLING UREIDE CONTENT AND ALLANTOINASE ACTIVITY DURING THE GERMINATION OF ADZUKI BEAN

赤豆种子萌发过程中,幼苗迅速合成酰脲,在酰脲含量达到最大值前,尿囊酸含量高于尿囊素含量,子叶合成酰脲最迅速;酰脲含量达到最大值后,茎带叶的酰脲含量最高。幼苗累积酰脲在品种间相似。种子萌发过程中,幼苗尿囊素酶活力迅速呈线性增加,且与酰脲含量变化趋势一致。幼苗尿囊素酶较耐热。

Changes of ureide, allantoin, allantoic acid content and al-lantoinase activity in adzuki bean(Vigna angularis)seedlings were investigated. Adzuki bean seeds were surface-sterilized in 0.1% HgCl2 (w/v) for 2 - 3 min and then washed repeatedly with redistilled water, aseptically germinated in the redistilled water at 28±1℃ in the dark unless otherwise specified. The seedlings synthesized ureide (allantoin and allantoic acid) rapidly during the germination. There was little difference in the seedling ureide accumulation among cultiyars. Before the seedling ureide content reached the maximum, the content of allantoic acid was higher than that of allantoin in the seedling, and the ureide content of cotyledon increased more rapidly than that of any other parts in the seedlings. Adzuki bean allantoinase activity appeared on the first day of germination and reached the maximum on the fourth day. Allantoinase from adzuki bean seedlings was remarkably heat-stable and would retain about 60% of the original activity after a seventy-minute pretreatment at 70℃.