植物精氨酸及其代谢产物的生理功能

Physiological Function of Arginine and Its Metabolites in Plants

L-精氨酸在植物中除作为一种重要的氮素贮藏营养物供再利用外,还是生成多胺(PA)和一氧化氮(NO)等的前体物质,而PA和NO都是植物中重要的信使分子,参与包括生长发育、抗逆性等在内的几乎所有的生理生化过程。精氨酸脱羧酶(ADC)、精氨酸酶和一氧化氮合酶(NOS)是L-精氨酸分解代谢的关键酶,精氨酸可经ADC或精氨酸酶-鸟氨酸脱羧酶(ODC)途径形成PA,也可经NOS途径形成NO,3个酶活性的相对强弱,决定了精氨酸的代谢方向。根系在越冬期间会积累丰富的精氨酸;精氨酸代谢对于植物感知和适应环境变化有重要意义。

L-Arginine is an important and unique amino acid in plants. It serves not only as an important nitrogen reserve and recycling, but also as a precursor of the biosynthesis of polyamines, nitric oxide and so on. Polyamines and nitric oxide are important messengers involved in almost all physiological and biochemical processes, growth ＆ development, and adaptation of plants to stress. Arginine decarboxylase, arginase and nitric oxide synthase are the key enzymes in L-arginine catabolism, in which polyamines are formed through ADC or arginase-ODC pathway while nitric oxide is formed through the NOS pathway. The relative activity of these three enzymes can control the direction of arginine metabolism. Arginine content keeps higher level in roots during overwinter period. The arginine metabolism plays important role in perception and adaptation of plant to environmental disturbances.