title: Effects of Fe deficiency on the protein profiles and lignin composition of stem tissues from Medicago truncatula in absence or presence of calcium carbonate.
abstract: Iron deficiency is a yield-limiting factor with major implications for crop production, especially in soils with high CaCO3. Because stems are essential for the delivery of nutrients to the shoots, the aim of this work was to study the effects of Fe deficiency on the stem proteome of Medicago truncatula. Two-dimensional electrophoresis separation of stem protein extracts resolved 276 consistent spots in the whole experiment. Iron deficiency in absence or presence of CaCO3 caused significant changes in relative abundance in 10 and 31 spots, respectively, and 80% of them were identified by mass spectrometry. Overall results indicate that Fe deficiency by itself has a mild effect on the stem proteome, whereas Fe deficiency in the presence of CaCO3 has a stronger impact and causes changes in a larger number of proteins, including increases in stress and protein metabolism related proteins not observed in the absence of CaCO3. Both treatments resulted in increases in cell wall related proteins, which were more intense in the presence of CaCO3. The increases induced by Fe-deficiency in the lignin per protein ratio and changes in the lignin monomer composition, assessed by pyrolysis-gas chromatography-mass spectrometry and microscopy, respectively, further support the existence of cell wall alterations.
  
  
  
  In spite of being essential for the delivery of nutrients to the shoots, our knowledge of stem responses to nutrient deficiencies is very limited. The present work applies 2-DE techniques to unravel the response of this understudied tissue to Fe deficiency. Proteomics data, complemented with mineral, lignin and microscopy analyses, indicate that stems respond to Fe deficiency by increasing stress and defense related proteins, probably in response of mineral and osmotic unbalances, and eliciting significant changes in cell wall composition. The changes observed are likely to ultimately affect solute transport and distribution to the leaves.
authors.affiliation: Plant Nutrition Department, Aula Dei Experimental Station (CSIC), P.O. Box 13034, E-50080, Zaragoza, Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: Rodríguez-Celma
authors.affiliation: Plant Nutrition Department, Aula Dei Experimental Station (CSIC), P.O. Box 13034, E-50080, Zaragoza, Spain.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lattanzio
authors.affiliation: Plant Nutrition Department, Aula Dei Experimental Station (CSIC), P.O. Box 13034, E-50080, Zaragoza, Spain.
authors.forename: Dido
authors.initials: D
authors.lastname: Villarroya
authors.affiliation: Plant Nutrition Department, Aula Dei Experimental Station (CSIC), P.O. Box 13034, E-50080, Zaragoza, Spain.
authors.forename: Elain
authors.initials: E
authors.lastname: Gutierrez-Carbonell
authors.affiliation: Plant Nutrition Department, Aula Dei Experimental Station (CSIC), P.O. Box 13034, E-50080, Zaragoza, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Ceballos-Laita
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Sevilla (CSIC), Reina Mercedes 10, E-41012 Sevilla, Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: Rencoret
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Sevilla (CSIC), Reina Mercedes 10, E-41012 Sevilla, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Gutiérrez
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Sevilla (CSIC), Reina Mercedes 10, E-41012 Sevilla, Spain.
authors.forename: José C
authors.initials: JC
authors.lastname: Del Río
authors.affiliation: USDA-ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Street, Houston, TX 77030, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Grusak
authors.affiliation: Plant Nutrition Department, Aula Dei Experimental Station (CSIC), P.O. Box 13034, E-50080, Zaragoza, Spain.
authors.forename: Anunciación
authors.initials: A
authors.lastname: Abadía
authors.affiliation: Plant Nutrition Department, Aula Dei Experimental Station (CSIC), P.O. Box 13034, E-50080, Zaragoza, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Abadía
authors.affiliation: USDA-ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Street, Houston, TX 77030, USA. Electronic address: lopezmil@bcm.edu.
authors.forename: Ana-Flor
authors.initials: AF
authors.lastname: López-Millán
mesh_terms: D002119:Calcium Carbonate / Q000494:pharmacology*; D002473:Cell Wall / Q000187:drug effects; D015180:Electrophoresis, Gel, Two-Dimensional; D007501:Iron / Q000494:pharmacology; D000090463:Iron Deficiencies; D008031:Lignin / Q000032:analysis; D013058:Mass Spectrometry; D046913:Medicago truncatula / Q000378:metabolism*; D010940:Plant Proteins / Q000032:analysis* / Q000187:drug effects; D018547:Plant Stems / Q000737:chemistry*; D020543:Proteome / Q000032:analysis / Q000187:drug effects; D040901:Proteomics / Q000379:methods
chemical_list: D010940:Plant Proteins; D020543:Proteome; D008031:Lignin; D007501:Iron; D002119:Calcium Carbonate
keywords: Iron; Lignin; Microscopy; Petiole; Proteomics; Stem; Two-dimensional gel electrophoresis