# Genetic and Environmental Factors Associated to Glutenin Polymer Characteristics of Wheat  
[PERSON]  
1 The French National Research Institute for Agriculture, Food and the Environment (INRAE), UCA UMR1095 GDEC, 5 Chemin de Beaulieu, 63100 Clermont-Ferrand, France;  
[EMAIL_ADDRESS] (G.B. ); [EMAIL_ADDRESS] (A.F. ); [EMAIL_ADDRESS] (V.L.) Institut Polytechnique UniLaSalle, Universite d'Artois, EA 7519, 19 rue [PERSON], BP 30313, 60026 Beauvais, France; [EMAIL_ADDRESS] (3) Department of Biosciences, COMSATS University Islamabad, Park Road, Tarlai Kalan, 45550 Islamabad, Pakistan; [EMAIL_ADDRESS] (4) Correspondence: [PERSON] Tel. : +33-(0)344-062-500 (4) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (2  
During grain development, the synthesis of GSPs is regulated by numerous transcription factors and by the availability of nitrogen and sulfur [6]. GSPs are synthesized in the endoplasmic reticulum and partly via the Golgi apparatus [7]. The proteins are accumulated in protein bodies, comprising a process of polymerization via interchain disulfide bonds (SS) of the high and low molecular weight glutenin subunits (HMW-GS and LMW-GS) and some \(\alpha\)-, \(\beta\)-, and \(\gamma\)-gliadins, with an odd number of cysteines [8]. The polymers, mainly composed of glutenin polymeric proteins (GPP), also contain the monomeric gliadins aggregated by hydrogen bonding and hydrophobic interactions [2]. During grain development, the formed polymers exhibit an exponential phase of accumulation of their SDS-phosphate-insoluble fractions, which is revealed around 30 days after anthesis (daa) at the end of the water plateau, corresponding to the initiation of grain dehydration [9; 10]. The compressed protein bodies release their material during dehydration/maturation of the grain, leaving the GSPs to surround the starch granules in the form of a fairly dense protein matrix. The kernel tissues are progressively engaged in programmed apoptosis [11]. Rather than using the electrophoresis techniques initially practiced to uncover the diversity of GSPs, high-performance liquid chromatography (HPLC) using size exclusion (SE) for molecular profiling has rapidly become the preferred tool for gluten sub-fraction analysis and quality characterization [12; 13]. The determination of the percentage of unextractable polymeric proteins (%UPP), obtained after a two-step extraction using SDS followed by sonication, through SE-HPLC [14] was implemented, particularly in Sweden [15; 16], but has also been used by many teams around world to approach some aspects of wheat quality and gluten strength or to evaluate influence of environmental factors on %UPP [17; 18]. The %UPP provides information on polymer abundance, and this is sometimes correlated to grain protein concentration (PC) but does not describe the molecular characteristics of the polymers. The second technique for analyzing these polymers requires molecular sieving in a double cross-flow gradient followed by multi-angle detection of the deviation caused on a laser beam (A4F-MALLS, Asymmetric Flow Field-Flow Fractionation Multi-Angle Laser Light Scattering) [19]. This technique offers the possibility to measure several parameters (like molecular mass (Mw) and hydrodynamic radius) on each polymer or to have a distribution of these molecular characteristics on the analyzed sample and to calculate an index of polydispersity of Mw. All these measurements are not offered by SE-HPLC. The maximum size sieving permitted by chromatography columns is around \(1\times 10^{6}\) Da, whereas polymer Mw higher than \(1\times 10^{7}\) g/mol have been reported for GPPs [19; 20]. The A4F-MALLS of GPP was used in several approaches, such as studying the quality stability of hybrid wheats over different environments [21], the influence of ozone treatment on wheat proteins and quality [22], or the effect of chitosan treatment on gluten proteins [23].