title: Interruption of magnesium supply at heading influenced proteome of peripheral layers and reduced grain dry weight of two wheat (Triticum aestivum L.) genotypes.
abstract: Magnesium (Mg), an indispensable mineral for plant growth, is concentrated in the peripheral layers (PLs) of the mature grain of wheat. The supply of Mg was interrupted from plant heading to maturity and a proteomic approach was used to investigate the PLs at three stages of development. Two genotypes with contrasting concentrations of Mg in the grain were studied: Apache (low Mg) and MgHL (high Mg). The concentration of Mg was significantly reduced in the roots (10-21%), straw (18-50%) and grain (24-10%), respectively. Mg deficiency altered enzymes involved in photosynthesis, glycolysis, respiration, amino acid synthesis, cell division, protein degradation and folding at early stages, especially in MgHL. This latter had smaller grain by reducing grain potential size and dry matter accumulation. By contrast in Apache, few proteins were affected at early stages and proteins related to stress/defense and arginine/proline metabolism were up accumulated resulting in lower number of grains per ear (24.9%). This study showed that Mg in PLs plays an important role in cell division, ATP generation, carbohydrate and amino acid metabolism, and hence may influence grain potential size and assimilates in grain, which determines grain weight. These results should help wheat breeders improve Mg content and hence grain yield.
  
  
  
  Magnesium (Mg) is an abundant cation and is involved in many cell activities. Its role in determining wheat productivity remains unclear. This study is the first to investigate how Mg deficiency influences the physiological characters of wheat and dry matter in the grain in two genotypes with contrasting Mg content. Moreover, Mg is concentrated in peripheral layers of grain, which are known to play a critical role in grain development. In this study, we investigated proteins in the peripheral layers expressed differentially in three development stages to identify the mechanism by which Mg influences grain development. This study revealed that the supply of Mg influences grain yield and that Mg regulates proteins related to cell metabolism and stress defense in grain.
authors.affiliation: INRA UMR 1095 Genetics, Diversity and Ecophysiology of Cereals (GDEC), 5 Chemin de Beaulieu, F63039 Clermont-Ferrand, France; Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong 518060, China; Veterinary and Agronomy Engineer School (VetAgroSup), 89 Avenue de l'Europe, F63370 Lempdes, France; Shenzhen Key Laboratory of Microbial Genetic Engineering, College of Life Sciences, Shenzhen University, Shenzhen, Guangdong 518060, China.
authors.forename: Huiling
authors.initials: H
authors.lastname: Qiu
authors.affiliation: INRA UMR 1095 Genetics, Diversity and Ecophysiology of Cereals (GDEC), 5 Chemin de Beaulieu, F63039 Clermont-Ferrand, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Nadaud
authors.affiliation: Blaise Pascal University, UMR 547 Integrative Physics and Physiology of Fruit and Forest Trees (PIAF), 24 Avenue des Landais, F63171 Aubière, France.
authors.forename: Gérard
authors.initials: G
authors.lastname: Ledoigt
authors.affiliation: Veterinary and Agronomy Engineer School (VetAgroSup), 89 Avenue de l'Europe, F63370 Lempdes, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Piquet-Pissaloux
authors.affiliation: INRA UMR 1095 Genetics, Diversity and Ecophysiology of Cereals (GDEC), 5 Chemin de Beaulieu, F63039 Clermont-Ferrand, France.
authors.forename: Gérard
authors.initials: G
authors.lastname: Branlard
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D002477:Cells / Q000378:metabolism; D002523:Edible Grain / Q000187:drug effects / Q000254:growth & development*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005838:Genotype; D008274:Magnesium / Q000032:analysis* / Q000494:pharmacology; D010940:Plant Proteins / Q000032:analysis*; D020543:Proteome / Q000032:analysis*; D014908:Triticum / Q000166:cytology / Q000235:genetics* / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D020543:Proteome; D008274:Magnesium
keywords: ATP generation; Aleurone layer; Globulin; Grain dry weight; Magnesium deficiency; Stress defense