Local inhibition of nitrogen fixation and nodule metabolism in drought-stressed soybean

Drought stress is a major factor limiting symbiotic nitrogen fixation (NF) in soybean crop production. However, the regulatory mechanisms involved in this inhibition are still controversial. Soybean plants were symbiotically grown in a split-root system (SRS), which allowed for half of the root syst...

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Detalhes bibliográficos
Autores: Gil Quintana, Erena, Larrainzar Rodríguez, Estíbaliz, Seminario Huárriz, Amaia, Díaz Leal, Juan Luis, Alamillo, Josefa M., Pineda, Manuel, Arrese-Igor Sánchez, César, Wienkoop, Stefanie, González García, Esther
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2013
País:España
Recursos:Universidad Pública de Navarra
Repositório:Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
OAI Identifier:oai:academica-e.unavarra.es:2454/24069
Acesso em linha:https://hdl.handle.net/2454/24069
Access Level:Acceso aberto
Palavra-chave:Drought
Local regulation
N-feedback inhibition
Nitrogen fixation
Proteomics
Soybean
Ureides
Descrição
Resumo:Drought stress is a major factor limiting symbiotic nitrogen fixation (NF) in soybean crop production. However, the regulatory mechanisms involved in this inhibition are still controversial. Soybean plants were symbiotically grown in a split-root system (SRS), which allowed for half of the root system to be irrigated at field capacity while the other half remained water deprived. NF declined in the water-deprived root system while nitrogenase activity was maintained at control values in the well-watered half. Concomitantly, amino acids and ureides accumulated in the water-deprived belowground organs regardless of transpiration rates. Ureide accumulation was found to be related to the decline in their degradation activities rather than increased biosynthesis. Finally, proteomic analysis suggests that plant carbon metabolism, protein synthesis, amino acid metabolism, and cell growth are among the processes most altered in soybean nodules under drought stress. Results presented here support the hypothesis of a local regulation of NF taking place in soybean and downplay the role of ureides in the inhibition of NF