Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, USA.
Amino Acids. 2012 Feb;42(2-3):813-30. doi: 10.1007/s00726-011-0998-8. Epub 2011 Aug 23.
Polyamines are organic polycations that are involved in a wide range of cellular activities related to growth, development, and stress response in plants. Higher polyamines spermidine and spermine are synthesized in plants and animals by a class of enzymes called aminopropyltransferases that transfer aminopropyl moieties (derived from decarboxylated S-adenosylmethionine) to putrescine and spermidine to produce spermidine and spermine, respectively. The higher polyamines show a much tighter homeostatic regulation of their metabolism than the diamine putrescine in most plants; therefore, the aminopropyltransferases are of high significance. We present here a comprehensive summary of the current literature on plant aminopropyltransferases including their distribution, biochemical properties, genomic organization, pattern of expression during development, and their responses to abiotic stresses, and manipulation of their cellular activity through chemical inhibitors, mutations, and genetic engineering. This minireview complements several recent reviews on the overall biosynthetic pathway of polyamines and their physiological roles in plants and animals. It is concluded that (1) plants often have two copies of the common aminopropyltransferase genes which exhibit redundancy of function, (2) their genomic organization is highly conserved, (3) direct enzyme activity data on biochemical properties of these enzymes are scant, (4) often there is a poor correlation among transcripts, enzyme activity and cellular contents of the respective polyamine, and (5) transgenic work mostly confirms the tight regulation of cellular contents of spermidine and spermine. An understanding of expression and regulation of aminopropyltransferases at the metabolic level will help us in effective use of genetic engineering approaches for the improvement in nutritional value and stress responses of plants.
多胺是参与植物生长、发育和应激反应等广泛细胞活动的有机多阳离子。高等多胺亚精胺和精胺在植物和动物中由一类称为氨基丙基转移酶的酶合成，该酶将氨基丙基部分（源自脱羧 S-腺苷甲硫氨酸）转移到腐胺和亚精胺上，分别产生亚精胺和精胺。与大多数植物中的二胺腐胺相比，高等多胺对其代谢的体内平衡调节更为严格；因此，氨基丙基转移酶具有重要意义。我们在此全面总结了植物氨基丙基转移酶的现有文献，包括它们的分布、生化特性、基因组组织、发育过程中的表达模式以及它们对非生物胁迫的反应，以及通过化学抑制剂、突变和遗传工程来操纵它们的细胞活性。这篇综述补充了关于多胺整体生物合成途径及其在植物和动物中的生理作用的几篇最近的综述。结论是：(1)植物通常有两个常见氨基丙基转移酶基因的拷贝，它们具有功能冗余；(2)它们的基因组组织高度保守；(3)直接酶活性数据关于这些酶的生化特性很少；(4)通常转录物、酶活性和各自多胺的细胞含量之间相关性较差；(5)转基因工作大多证实了细胞内精胺和精胺含量的严格调节。在代谢水平上理解氨基丙基转移酶的表达和调节将有助于我们有效利用遗传工程方法来提高植物的营养价值和应激反应能力。
