Physiological and metabolic changes in nodulated pea plants (Pisum sativum L.) induced by sulphur deficiency

• Olaya Muñoz-Azcárate ^[1] ; Joseba Aldasoro ^[1] ; Cesar Arrese-Igor ^[1]
  1. [1] Universidad Pública de Navarra

     Universidad Pública de Navarra

     Pamplona, España

     
• Localización: SEFV 2011: programa de sesiones y resúmenes de conferencias plenarias e invitadas / coord. por Vicent Arbona Mengual, Rosa María Pérez Clemente, María Fernanda López Climent, Aurelio Gómez Cadenas, 2011, ISBN 978-84-8021-805-4, pág. 47
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • Nitrogen-fixing symbioses between legume plants and rhizobia are the largest natural source ofnitrogen for agriculture. They constitute a sustainable alternative to nitrogen fertilizers, but theirsensitivity to abiotic stresses limits its extended use. Sulphur (S) deficiency has receivedincreased attention in last decades as a limiting factor in agriculture. Decreases in biologicalnitrogen fixation (BNF) and nodule biomass in S-deficient conditions were reported in somestudies, although they did not deal with specific effects of S in nodule development andmetabolism in depth.Nodulated pea plants were grown in an aerated hydroponic solution, in a controlledenvironment. The day of transplanting, a group of seedlings was transferred to an S-freehydroponic solution (S0 plants), and another group was transferred to the S-free solution sevendays after transplanting (DAT) (S7 plants). Another group was kept under full nutrientsavailability (control plants). BNF, photosynthesis and root, shoot and nodule biomass weremeasured 28 DAT. Amino acids, organic acids, and sugar content were analyzed in shoot, rootand nodule frozen aliquots, and enzymatic activities of nodule carbon metabolism were assayed.Root and shoot biomass was similar for all treatments, but the shoot/root ratio decreased in bothS7 and S0 plants. Nodule biomass, BNF and photosynthesis were significantly lower in both Sdeprivedtreatments. Aromatic and branched-chain amino acids increased significantly in S0nodules, while Glu, Gln and Asn content decreased, as well as sucrose and glucose content.Sucrose synthase and phosphoenolpyruvate carboxylase activities decreased upon sulphurstarvation. Thus, it appears that S-deficiency indices an impaired nodule metabolism. Furthermolecular and metabolic analyses are under way in order to determine the specific effects of Sdeficiency at a whole plant level.