Nucleotide Sequence of a cDNA Encoding a Soybean Seedling Axes Arginase (Accesion No. AF035671).

ARIEL GOLDRAIJ; PATRICIA COELLO; JOE POLACCO

PLANT PHYSIOLOGY.

American Society of Plant Biologists

Lugar: Rockville, MD,USA; Año: 1998 vol. 116 p. 867 - 867

0032-0889

p>Arginine is an important nitrogen transport and storage compound which plays a critical role in the nitrogen economy of many plants. In soybean, arginine accounts for 18 % of the total seed protein nitrogen and up to 62 % of free amino acid nitrogen in developing embryos is in the arginine pool (Micallef and Shelp, 1989a). The first step of arginine degradation is catalyzed by arginase (L-Arg amidinohydrolase, EC 3.5.3.1), rendering urea and L-Ornithine. The nitrogen contained in urea is recycled to ammonia by urease action (Polacco and Holland, 1993) and ornithine is a precursor of proline, glutamic acid and polyamines. While arginine is actively synthesized in developing soybean cotyledons, arginase has been postulated to be inoperative in vivo (Stebbins et al, 1991) or to hydrolyze a minor portion of the large free arginine pool (Micallef and Shelp, 1989b). In contrast developing soybean cotyledon arginase is e