多胺(PAs)与植物的几种胁迫反应

POLYAMINE AND PLANT STRESS

多胺（ＰＡｓ）是一类具有强烈生理活性的低分子量含氮碱。它们不仅调节植物的生长、发育，还参与植物的胁迫反应。当植物遭受水分胁迫、酸胁迫、盐胁迫、离子胁迫、低温胁迫等各种逆境时，多胺合成酶活力增加，腐胺（Ｐｕｔ）大量累积。Ｐｕｔ作为一种有机阳离子，实际上起着调节细胞ｐＨ作用。胁迫条件下，Ｐｕｔ的大量合成也许是对细胞质酸化的一种反应。Ｐｕｔ还调节活性氧代谢的平衡，在稳定膜结构。

The putrescine and spermidine accumulate in higher plants in response to various stresses. The rise of putrescine (Put) is paralleled by an increase in the activity of arginine decarboxylase. The Put is as an organic cation, its accumulation is a response to acidification of the cytoplasm resulting from cation/anion imbalance in order to regulate cellular pH, perhaps, Put may have a key position in nitrogen metabolism which has not been fully realized yet.