Metabolic Fate of Adenosine and Purine Metabolism Enzymes in Young Plants of Peach Tree

• Published in: Journal of plant physiology 1995, Vol.145 (4), p.398-404
• Main Authors: Le Floc'h, François, Faye, Florence
• Format: Article
• Language: English
• Subjects: ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; Adeninnucleotid; Adenosin; ADENOSINA; ADENOSINE; Adenosine recycling; Agronomy. Soil science and plant productions; Biochemie; Biological and medical sciences; Dormancy; Economic plant physiology; Enzymaktivitaet; ENZYMIC ACTIVITY; Flowering, floral biology, reproduction patterns; FOSFORILACION; Fundamental and applied biological sciences. Psychology; Growth and development; METABOLISM; METABOLISME; METABOLISMO; NUCLEOTIDE; NUCLEOTIDES; NUCLEOTIDOS; Obstbau; Peach tree; Pfirsich; PHOSPHORYLATION; Phosphorylierung; Plant growth. Development of the storage organs; Plant physiology and development; PLANTULAS; PLANTULE; PRUNUS PERSICA; Prunus persica L. Batsch; Purin; purine metabolism enzymes; Saemling; SEEDLINGS; Stoffwechsel; Vegetative apparatus, growth and morphogenesis. Senescence
• ISSN: 0176-1617; 1618-1328
• DOI: 10.1016/S0176-1617(11)81761-X

Extracts of young plants of peach tree, Prunus persica L. Batsch, exhibited the ability to recycle adenosine into adenine nucleotides either by phosphorylation into AMP by a very active adenosine kinase (EC 2.7.1.20) or by the successive intervention of adenosine nucleosidase (EC 3.2.2.7) and adenine phosphoribosyltransferase (EC 2.4.2.7). This latter sequence appeared to be the preferential salvage pathway of exogenous [U- 14C]adenosine in situ. In situ radiolabelling gave evidence of interconversion of adenine nucleotides into guanine nucleotides. Characterization of AMP aminohydrolase (EC 3.5.4.6) and guanylate kinase (EC 2.7.4.8) activities in extracts supported this observation. Peach tree AMP aminohydrolase, a particulate allosteric enzyme, revealed to be activated by K + ions and free ATP while guanylate kinase, also a particulate enzyme, required Mg-ATP 2- complex as substrate. Extracts of peach tree exhibited 5' nucleosidase and inosine nucleosidase activity (EC 3.2.2.2), likely involved in purine nucleotide catabolism occurring in situ. A metabolic scheme of salvage, interconversion and catabolic pathways of adenosine derivatives in young plants of peach tree is established and discussed.