植物精氨酸及其代谢产物的生理功能

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-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。

Physiological Function of Arginine and Its Metabolites in Plants

L-Arginine is an important and unique amino acid in plants. It serves not only as an im-portant nitrogen reserve and recycling,but also as a precursor of the biosynthesis of polyamines,ni-tric 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 ni-tric oxide is formed through the NOS pathway. The relative activity of these three enzymes can con-trol the direction of arginine metabolism. Argin-ine content keeps higher level in roots during over-winter period. The arginine metabolism plays im-portant role in perception and adaptation of plant to environmental disturbances.