Stress-induced declines in soybean N2 fixation are related to nodule sucrose synthase activity

• Published in: Plant physiology (Bethesda) 1997-07, Vol.114 (3), p.937-946
• Main Authors: Gordon, A.J, Minchin, F.R, Skot, L, James, C.L
• Format: Article
• Language: English
• Subjects: ACIDE AMINE; ACIDE ASCORBIQUE; ACIDE ORGANIQUE; ACIDO ASCORBICO; ACIDOS ORGANICOS; ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; Agronomy. Soil science and plant productions; ALMIDON; AMIDAS; AMIDE; AMIDES; AMIDON; AMINO ACIDS; AMINOACIDOS; ANALISIS CUANTITATIVO; ANALYSE QUANTITATIVE; Antinuclear antibodies; ARN MENSAJERO; ARN MESSAGER; ASCORBIC ACID; Biological and medical sciences; CARBOHIDRATOS; CARBOHYDRATES; CHEMICAL COMPOSITION; CHLORURE DE SODIUM; CLORURO SODICO; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; CORTE; CUTTING; DECOUPAGE; DROUGHT; ECHANGE GAZEUX; Economic plant physiology; Enzymes; ENZYMIC ACTIVITY; EXPRESION GENICA; EXPRESSION DES GENES; FIJACION DEL NITROGENO; FIXATION DE L'AZOTE; Fundamental and applied biological sciences. Psychology; GAS EXCHANGE; GENE EXPRESSION; GENETIC REGULATION; GENETICA; GENETICS; GENETIQUE; GLICOSILTRANSFERASAS; GLUCIDE; GLUTAMATE-AMMONIA LIGASE; GLUTAMINA; GLUTAMINE; GLUTARIC ACID; GLYCINE MAX; GLYCOSYLTRANSFERASE; GLYCOSYLTRANSFERASES; INDUCTION; INTERCAMBIO DE GASES; LEGAHEMOGLOBINA; LEGHAEMOGLOBIN; LEGHEMOGLOBIN; LEGHEMOGLOBINE; LIGASAS; LIGASE; LIGASES; MERISTEMAS; MERISTEME; MERISTEMS; MESSENGER RNA; METABOLISM; METABOLISME; METABOLISMO; NITRATE; NITRATES; NITRATOS; NITROGEN FIXATION; NITROGENASA; NITROGENASE; NODOSITE RACINAIRE; Nodules; NUDOSIDADES RADICULARES; ORGANIC ACIDS; OXIGENO; OXYGEN; OXYGENE; Parasitism and symbiosis; PEROXIDASAS; PEROXIDASES; PEROXYDASE; Plant physiology and development; Plants; QUANTITATIVE ANALYSIS; ROOT NODULES; SACCHAROSE; SECHERESSE; SEQUIA; SHOOT MERISTEMS; SODIUM CHLORIDE; Soybeans; STARCH; STEMS; STRESS RESPONSE; SUCROSA; SUCROSE; Symbiosis; Symbiosis (nodules, symbiotic nitrogen fixation, mycorrhiza...); TALLO; TIGE; TRANSCRIPCION; TRANSCRIPTION; TRANSFERASAS; TRANSFERASE; TRANSFERASES; UREIDES; Whole Plant, Environmental, and Stress Physiology
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.114.3.937

Soybean (Glycine max L.) plants were subjected to a number of treatments (drought, 10 mM nitrate, 150 mM NaCl, shoot meristem removal, and removal of approximately 50% of the nodules) to test the hypothesis that metabolic responses contribute to the regulation of N2 fixation. Nitrogenase activity was correlated with the activity of nodule sucrose synthase (SS), but not with that of glutamine oxoglutarate amino transferase. Leghemoglobin levels and other enzyme activities were not significantly or consistently affected by the treatments. SS mRNA was greatly reduced in nodules of drought-, salt-, and nitrate-treated plants; however, this was not correlated with changes in soluble carbohydrate, starch, amino acids, or ureides. Leghemoglobin mRNA was only slightly affected by the treatments. The time course of drought stress showed a decline in the SS transcript level by 1 d, but levels of leghemoglobin, glutamine synthetase, and ascorbate peroxidase mRNA were not markedly affected by 4 d. SS activity at 4 d was reduced by 46%. We propose that N2 fixation in soybean nodules is mediated by both the oxygen-diffusion barrier and the potential to metabolize sucrose via SS. The response to environmental perturbation may involve down-regulation of the nodule SS gene