School of Botany, University of Melbourne, 3052, Parkville, Vic, Australia.
Planta. 1979 Dec;147(2):117-21. doi: 10.1007/BF00389510.
The radicle of the pea embryo (Pisum sativum L.) is known to possess a range of protein-degrading enzymes which could theoretically act in vivo to break down proteins stored in the radicle. However, most of the polypeptides of the radicle showed little evidence of net breakdown in vivo in the first 4 days from imbibition. One polypeptide, of mol. mass 13,000, was degraded almost completely between 1 and 2 days from imbibition; others, of mol. mass 84,000 and 30,000 were degraded within 4 days. The breakdown of polypeptides stored in the radicle (and plumule) is thus highly selective and closely regulated. The requirement for amino nitrogen in the growing axis is evidently met by the immediate export of amino acids from the cotyledons, rather than by massive breakdown of stored polypeptides in situ.
豌豆胚根（Pisum sativum L.）中的胚根具有一系列蛋白降解酶，这些酶理论上可以在体内发挥作用，从而分解胚根中储存的蛋白质。然而，在吸水后前 4 天，大多数胚根多肽在体内几乎没有明显的净降解证据。有一种分子量为 13000 的多肽在吸水后 1 至 2 天内几乎完全降解；分子量为 84000 和 30000 的其他多肽在 4 天内降解。因此，储存在胚根（和胚芽）中的多肽的降解具有高度的选择性和严格的调控。生长轴对氮的需求显然是通过从子叶中立即输出氨基酸来满足的，而不是通过大量分解储存的多肽来满足的。
