Nov 8, 2018 - Classification and Polymorphism of Wheat Grain Proteins ... SDS-insoluble polymers/total polymers ratio is Strongly correlated with the ... Variation of the content of polymeric proteins conjugated to glutathione (PPSSG) for.
INTEGRATED APPROACH TO UNDERSTAND THE FUNCTIONING OF WHEAT QUALITY COMPONENTS AND THEIR INTERACTION WITH ENVIRONMENTS
LARBI RHAZI & THIERRY AUSSENAC EA 7519 TRANSFORMATIONS & AGRO-RESSOURCES
ICC International Conference GRAINS FOR WELLBEING Taipei, Chinese Taipei 5 - 8 November 2018
INTEGRATED APPROACH TO UNDERSTAND THE FUNCTIONING OF WHEAT QUALITY COMPONENTS AND THEIR INTERACTION WITH ENVIRONMENTS Introduction
Hoseney and Rogers 1990
GRAINS FOR WELLBEING Taipei, Chinese Taipei; 5 - 8 November 2018
MOLECULAR WEIGHT DISTRIBUTION (MWD) OF WHEAT STORAGE PROTEINS Classification and Polymorphism of Wheat Grain Proteins
GRAINS FOR WELLBEING Taipei, Chinese Taipei; 5 - 8 November 2018
MOLECULAR WEIGHT DISTRIBUTION (MWD) OF WHEAT STORAGE PROTEINS Gliadin to Glutenin Ratio: A structural model for wheat gluten
Monomeric Gliadins : Viscosity, Extensibility Lamacchia et al., 2014
Polymeric Glutenins : Tenacity, Elasticity
MOLECULAR WEIGHT DISTRIBUTION (MWD) OF WHEAT STORAGE PROTEINS Analytical methods
SEC-HPLC
The amount of glutenin aggregates, Monomer to polymer ratio, Soluble to insoluble ratio,
The bread-making quality
MOLECULAR WEIGHT DISTRIBUTION (MWD) OF WHEAT STORAGE PROTEINS Distribution of Glutenin subunits Lab-On-Chip
RP-HPLC
Quantitative and qualitative analysis: HMW, HMW-GS/HMW-GS HMW-GS/LMW-GS Translocations
MOLECULAR WEIGHT DISTRIBUTION (MWD) OF PROTEIN AGGREGATES Size Distribution of Polymeric Proteins Size Distribution of Polymeric Proteins
Glutenin aggregates: Molecular weight, molecular size, And conformation
Technological parameters (W, P, L …)
Asymmetrical flow field-flow fractionation (A4F) + MALLS
MOLECULAR WEIGHT DISTRIBUTION (MWD) OF PROTEIN AGGREGATES Size Distribution of Polymeric Proteins
Glutenin subunits (i.e. HMW-GS, LMW-GS, A-FFFF / MALLS / RI /UV and HMW-GS x and y type) are unequally Hierarchical arrangement of HMW-GS distributed within polymers and LMW-GS in relation to their intrinsic contribution to polymer formation Kasarda 1999
(Aussenac T., Rhazi L. 2018. J. Exp. Bot. in press.)
GRAINS FOR WELLBEING Taipei, Chinese Taipei; 5 - 8 November 2018
ACCUMULATION OF PROLAMINS IN DEVELOPING WHEAT GRAINS Accumulation of total polymers, SDS-soluble and SDS-insoluble polymers (●) Soissons and, (O) Thésée.
Open symbols = Thésée, closed symbols = Soissons. (▲, Δ)SDS-soluble polymers; (●,O) SDS-insoluble polymers.
The UPP accumulation phase coincides very strongly with the grain desiccation phase SDS-insoluble polymers/total polymers ratio is Strongly correlated with the HMW-GS/LMW-GS ratio
ACCUMULATION OF PROLAMINS IN DEVELOPING WHEAT GRAINS Unextractable Polymeric Protein (UPP) accumulation
The UPP accumulation phase coincides with the oxidation of protein SH
The existence of a late mechanism of storage protein oxidation (i.e. formation of SS bonds from SH groups)
Change in sulfhydryl status of wheat proteins during grain development and maturation
IMPACTS OF ENVIRONMENTAL FACTORS ON MWD OF PROLAMINS The impact of environmental components on the molecular weight distribution of proteins 130 Soft wheat genotypes grown in 3 different environments/2 cropping seasons
Parameters
Minimum
Maximum
Mean
value
value
value
2G/2R
2E/2R
Total proteins(1)
8.700
15.100
11.187
11.411***
271.577***
Total polymers(1)
2.785
5.755
4.016
11.104***
187.462***
Polymer/monomer
0.321
0.700
0.561
14.845***
72.611***
Polymer Mn(2)
0.730 x106
9.609 x106
0.972 x106
1.068NS
4.383***
Polymer Mw(2)
1.142 x106
22.970 x106
7.640 x106
3.370***
38.974***
Variations: Unextracatble Polymeric Proteins (UPP)/ TP ratio, Extractable Proteins/TP ratio, UPP/EP and distribution of glutenin subunits The impact of environmental components on the molecular weight distribution of the prolamins is significantly greater than that of genetic components
IMPACTS OF ENVIRONMENTAL FACTORS ON MWD OF PROLAMINS Glutathione disulfide-dependent protection of protein thiol groups during desiccation
DH, Dehydration steps. GSH, reduced glutathione; GSSG, glutathione disulfide; GR, glutathione reductase.
IMPACTS OF ENVIRONMENTAL FACTORS ON MWD OF PROLAMINS Changes in PP and PP-S-S-G content during the grain development
Open symbols = cv. Soissons Closed symbols = cv. Thésée.
The formation of coincide with the desiccation phase
The great majority of PSSG is present in the grain in the form of PP-S-S-G (≈85%).
PSSG grain
IMPACTS OF ENVIRONMENTAL FACTORS ON MWD OF PROLAMINS Accumulation of PP and PP-S-S-G: correlations The relationship between the content of high aggregated polymeric proteins (PP with Mw>2 106 g.mol-1) And the content of polymeric proteins conjugated to glutathione (PPSSG)
GSH plays a crucial role in controlling the MWD of the polymeric proteins
IMPACTS OF ENVIRONMENTAL FACTORS ON MWD OF PROLAMINS Accumulation of PP-S-S-G: Genetic impact Glutathione conjugation with polymeric proteins during the grain development results in drastic changes of the cellular redox status
Variation of the content of polymeric proteins conjugated to glutathione (PPSSG) for 130 cultivars
Conclusions Glutenins are largely under the control of protein polymorphism (nature and relative abundance of LMW-GS and HMW-GS Glutenins are largely under the control of the conditions of development and maturation of the grains. Significant work needs to be done to better understand the structure of protein assemblies of technological interest (UPP or GMP). Understand the mechanisms that govern the formation of these polymers and/or protein aggregates in wheat grains during the final stages of their development The important role of cellular redox status It is also important to integrate the methods discussed during this presentation in the varietal stability studies GRAINS FOR WELLBEING Taipei, Chinese Taipei; 5 - 8 November 2018
Thank you for your attention!
GRAINS FOR WELLBEING Taipei, Chinese Taipei; 5 - 8 November 2018