Data/hora: 29/05/2024 00:27:29

Biblioteca(s): | Embrapa Soja.
Data corrente: | 22/09/1992
Data da última atualização: | 22/09/1992
Autoria: | KOHL, D. H.; LIN, J. J.; SHEARER, G.; SCHUBERT, K. R.
Afiliação: | Biology Department, Washington University, St. Louis, Missouri 63130.
Título: | Activities of the pentose phosphate pathway and enzymes of proline metabolism in legume root nodules.
Ano de publicação: | 1990
Fonte/Imprenta: | Plant Physiology, v.94, p.1258-1264, 1990.
Idioma: | Inglês
Conteúdo: | Based on localization and high activities of pyrroline-5-carboxyiate reductase and proline dehydrogenase activities in soybean nodules, we previously suggested two major roles for pyrroline-5-carboxylate reductase in addition to the production of the considerable quantity of proline needed for biosynthesis: namely, transfer of energy to the location of biological N2 fixation, and production of NADP+ to drive the pentose phosphate pathway. The latter produces ribose-5-phosphate which can be used in de novo purine synthesis required for synthesis of ureides, the majos form in which biologically fixed N2 is transported from soybean root nodules to the plant shoot. In this paper, we report rapid induction (in soybean nodules) and exceptionally high activities (in nodules of eight species of N2-fixing plants) of pentose phosphate pathway and pyrroline-5-carboxylate reuctase. There was a marded increase in proline dehydrogenase activity during soybean (Glycine max) ontogeny. The magnitude of proline dehydrogenase activity in bacteroids of soybean nodles was sufficiently high during most of the time course to supply a significant fraction of the energy requirement for N2 fixation. Proline dehydrogenase activity in bacteroids from nodules of other species was also high. These observations support the above hypothesis. How-ever, comparison of pentose phosphate patway and pyrroline-5-carboxylate reductase activities of ureide versus amide-exporting nodules offers no support. The hypothesis predicts that pyrroline-5-.....
Palavras-Chave: | C; Fixacao; Fixation; N; N2; Soybean.
Thesagro: | Bradyrhizobium Japonicum; Glycine Max; Metabolismo; Prolina; Soja.
Thesaurus Nal: | metabolism; proline.
Categoria do assunto: | --
Registro original: | Embrapa Soja (CNPSO)
Exemplares: | CNPSO - (13909-1) - ADD - SP - -- - 9768 -  - 9768 - DIS