title: Three-Dimensional Reconstruction, by TEM Tomography, of the Ultrastructural Modifications Occurring in Cucumis sativus L. Mitochondria under Fe Deficiency.
abstract: BACKGROUND
  Mitochondria, as recently suggested, might be involved in iron sensing and signalling pathways in plant cells. For a better understanding of the role of these organelles in mediating the Fe deficiency responses in plant cells, it is crucial to provide a full overview of their modifications occurring under Fe-limited conditions. The aim of this work is to characterize the ultrastructural as well as the biochemical changes occurring in leaf mitochondria of cucumber (Cucumis sativus L.) plants grown under Fe deficiency.
  
  
  RESULTS
  Mitochondrial ultrastructure was investigated by transmission electron microscopy (TEM) and electron tomography techniques, which allowed a three-dimensional (3D) reconstruction of cellular structures. These analyses reveal that mitochondria isolated from cucumber leaves appear in the cristae junction model conformation and that Fe deficiency strongly alters both the number and the volume of cristae. The ultrastructural changes observed in mitochondria isolated from Fe-deficient leaves reflect a metabolic status characterized by a respiratory chain operating at a lower rate (orthodox-like conformation) with respect to mitochondria from control leaves.
  
  
  CONCLUSIONS
  To our knowledge, this is the first report showing a 3D reconstruction of plant mitochondria. Furthermore, these results suggest that a detailed characterization of the link between changes in the ultrastructure and functionality of mitochondria during different nutritional conditions, can provide a successful approach to understand the role of these organelles in the plant response to Fe deficiency.
authors.affiliation: Dipartimento di Scienze Agrarie e Ambientali-Produzione, Territorio, Agroenergia, Università degli Studi di Milano, Milano, Italy.
authors.forename: Gianpiero
authors.initials: G
authors.lastname: Vigani
authors.affiliation: Dipartimento di Scienze Agrarie e Ambientali-Produzione, Territorio, Agroenergia, Università degli Studi di Milano, Milano, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Faoro
authors.affiliation: Istituto di Scienze e Tecnologie Molecolari, Consiglio Nazionale delle Ricerche, Milano, Italy.
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Ferretti
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Milano, Milano, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Cantele
authors.affiliation: Dipartimento di Scienze Agrarie e Ambientali-Produzione, Territorio, Agroenergia, Università degli Studi di Milano, Milano, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Maffi
authors.affiliation: Istituto di Scienze e Tecnologie Molecolari, Consiglio Nazionale delle Ricerche, Milano, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Marelli
authors.affiliation: Dipartimento di Scienze Agrarie e Ambientali-Produzione, Territorio, Agroenergia, Università degli Studi di Milano, Milano, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Maver
authors.affiliation: Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy.
authors.forename: Irene
authors.initials: I
authors.lastname: Murgia
authors.affiliation: Dipartimento di Scienze Agrarie e Ambientali-Produzione, Territorio, Agroenergia, Università degli Studi di Milano, Milano, Italy.
authors.forename: Graziano
authors.initials: G
authors.lastname: Zocchi
mesh_terms: D018553:Cucumis sativus / Q000378:metabolism / Q000648:ultrastructure*; D055032:Electron Microscope Tomography; D004579:Electron Transport / Q000502:physiology; D000090463:Iron Deficiencies; D008928:Mitochondria / Q000378:metabolism / Q000648:ultrastructure*; D018515:Plant Leaves / Q000378:metabolism / Q000648:ultrastructure*; D015398:Signal Transduction