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Functional replacement of ferredoxin by a cyanobacterial flavodoxin in tobacco confers broad-range stress tolerance.
Tognetti, Vanesa B; Palatnik, Javier F; Fillat, María F; Melzer, Michael; Hajirezaei, Mohammad-Reza; Valle, Estela M; Carrillo, Néstor.
Afiliação
  • Tognetti VB; Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, División Biología Molecular, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, S2002LRK Rosario, Argentina.
Plant Cell ; 18(8): 2035-50, 2006 Aug.
Article em En | MEDLINE | ID: mdl-16829589
Chloroplast ferredoxin (Fd) plays a pivotal role in plant cell metabolism by delivering reducing equivalents to various essential oxidoreductive pathways. Fd levels decrease under adverse environmental conditions in many microorganisms, including cyanobacteria, which share a common ancestor with chloroplasts. Conversely, stress situations induce the synthesis of flavodoxin (Fld), an electron carrier flavoprotein not found in plants, which can efficiently replace Fd in most electron transfer processes. We report here that chloroplast Fd also declined in plants exposed to oxidants or stress conditions. A purified cyanobacterial Fld was able to mediate plant Fd-dependent reactions in vitro, including NADP+ and thioredoxin reduction. Tobacco (Nicotiana tabacum) plants expressing Fld in chloroplasts displayed increased tolerance to multiple sources of stress, including redox-cycling herbicides, extreme temperatures, high irradiation, water deficit, and UV radiation. Oxidant buildup and oxidative inactivation of thioredoxin-dependent plastidic enzymes were decreased in stressed plants expressing plastid-targeted Fld, suggesting that development of the tolerant phenotype relied on productive interaction of this flavoprotein with Fd-dependent oxidoreductive pathways of the host, most remarkably, thioredoxin reduction. The use of Fld provides new tools to investigate the requirements of photosynthesis in planta and to increase plant stress tolerance based on the introduction of a cyanobacterial product that is free from endogenous regulation in higher plants.
Assuntos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Nicotiana / Anabaena / Ferredoxinas / Flavodoxina Idioma: En Revista: Plant Cell Assunto da revista: BOTANICA Ano de publicação: 2006 Tipo de documento: Article País de afiliação: Argentina País de publicação: Reino Unido

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Nicotiana / Anabaena / Ferredoxinas / Flavodoxina Idioma: En Revista: Plant Cell Assunto da revista: BOTANICA Ano de publicação: 2006 Tipo de documento: Article País de afiliação: Argentina País de publicação: Reino Unido