scholarly journals Sequence Diversity and Identification of Novel Puroindoline and Grain Softness Protein Alleles in Elymus, Agropyron and Related Species

Diversity ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 114 ◽  
Author(s):  
Mark Wilkinson ◽  
Robert King ◽  
Roberta Grimaldi
Keyword(s):  
Sequence Diversity ◽  
Grain Texture ◽  
Grain Hardness ◽  
Hydrophobic Residues ◽  
Rich Domain ◽  
Elymus Nutans ◽  
End Use ◽  
Grain Softness ◽  
Novel Variation ◽  
Grain Softness Protein

The puroindoline proteins, PINA and PINB, which are encoded by the Pina and Pinb genes located at the Ha locus on chromosome 5D of bread wheat, are considered to be the most important determinants of grain hardness. However, the recent identification of Pinb-2 genes on group 7 chromosomes has stressed the importance of considering the effects of related genes and proteins. Several species related to wheat (two diploid Agropyron spp., four tetraploid Elymus spp. and five hexaploid Elymus and Agropyron spp.) were therefore analyzed to identify novel variation in Pina, Pinb and Pinb-2 genes which could be exploited for the improvement of cultivated wheat. A novel sequence for the Pina gene was detected in Elymus burchan-buddae, Elymus dahuricus subsp. excelsus and Elymus nutans and novel PINB sequences in Elymus burchan-buddae, Elymus dahuricus subsp. excelsus, and Elymus nutans. A novel PINB-2 variant was also detected in Agropyron repens and Elymus repens. The encoded proteins detected all showed changes in the tryptophan-rich domain as well as changes in and/or deletions of basic and hydrophobic residues. In addition, two new AGP sequences were identified in Elymus nutans and Elymus wawawaiensis. The data presented therefore highlight the sequence diversity in this important gene family and the potential to exploit this diversity to modify grain texture and end-use quality in wheat.

scholarly journals The effect of friabilin on wheat grain hardness: a review

2008 ◽  
Vol 43 (No. 2) ◽  
pp. 35-43 ◽  
Author(s):  
D. Mikulíková
Keyword(s):  
Active Form ◽  
Surface Protein ◽  
Grain Texture ◽  
Grain Hardness ◽  
Wheat Grain ◽  
Wheat Varieties ◽  
In The Wild ◽  
Tillage System ◽  
Grain Softness ◽  
Endosperm Texture

A wheat marketing system established the primary classification of hexaploid wheat based on the endosperm texture, i.e. hardness or softness of the grain. Hardness affects a range of characters including the milling (tempering, milling yield, flour particle size, shape and density of flour particles), baking and end-use properties. Wheat grain hardness is largely controlled by genetic factors but it can also be affected by the environmental and other factors. The endosperm texture is primarily associated with the <i>Hardness</i> (<i>Ha</i>) locus on the short arm of chromosome 5D. It is regulated by friabilin. This 15 kDa starch surface protein complex is present in larger amounts in soft wheats compared to hard ones and consists of three major polypeptides: puroindoline a (<i>Pina</i>), puroindoline b (<i>Pinb</i>) and grain softness protein 1 (<i>Gsp-1</i>). The soft grain texture in wheat is a result of both puroindoline genes being in the wild type active form and bound to starch. When one of the puroindolines is either absent or altered by mutation, then the result is a hard texture. Gene sequence variation and mutation of both puroindoline genes account for the majority of variation in the wheat grain texture. The latter may serve as the potential for improvement of milling and baking wheat quality. However, many wheat varieties have the intermediately (mixed) hard endosperm and there is a wide variation between soft and hard grain texture. Grain hardness is affected by a number of factors beyond genetics including N management, tillage system, pest infestations, environment (location of growth, temperature and rainfall during the growing season) and their interactions, and factors such as moisture, gliadin composition, and content of lipids, starch and pentosans.

Grain Hardness: A Major Determinant of Wheat Quality

2010 ◽  
Vol 16 (6) ◽  
pp. 511-522 ◽  
Author(s):  
I. Pasha ◽  
F.M. Anjum ◽  
C.F. Morris
Keyword(s):  
Hardness Measurement ◽  
Specific Protein ◽  
Quality Characteristic ◽  
Wheat Quality ◽  
Grain Hardness ◽  
Texture Measurement ◽  
End Use ◽  
Complex Term ◽  
Grain Softness ◽  
Endosperm Texture

Wheat quality, a complex term, depends upon intentional use for unambiguous products. The foremost determinants of wheat quality are endosperm texture (grain hardness), protein content and gluten strength. Endosperm texture in wheat is the single most important and defining quality characteristic, as it facilitates wheat classification and affects milling, baking and end-use quality. Various techniques used for grain hardness measurement are classified into diverse groups according to grinding, crushing and abrasion. The most extensively used methods for texture measurement are PSI, NIR hardness, SKCS, pearling index, SDS-PAGE and PCR markers. Friabilin is a 15 kDa endosperm specific protein associated with starch granules of wheat grain and is unswervingly related to grain softness. Chemically, it is a concoction of different polypeptides, primarily puroindolines; Pin a and Pin b. Hardness (Ha) locus of chromosome 5DS makes the distinction between soft and hard classes of wheat. Some additional modifying genes are also present which contribute to the disparity within wheat classes. Numerous allelic mutations in Pin have been reported and their relation to end product quality has been established. This treatise elaborates the consequence of grain hardness in wheat eminence.

The Nor-D3 locus of Triticum tauschii: natural variation and genetic linkage to markers in chromosome 5

Genome ◽  
1991 ◽  
Vol 34 (3) ◽  
pp. 387-395 ◽  
Author(s):  
E. S. Lagudah ◽  
R. Appels ◽  
D. McNeil
Keyword(s):  
Ribosomal Rna ◽  
Intergenic Spacer ◽  
D Genome ◽  
Triticum Tauschii ◽  
Intergenic Spacer Region ◽  
Grain Softness ◽  
High Level ◽  
Rna Genes ◽  
Rdna Polymorphism ◽  
Grain Softness Protein

Variation in the intergenic spacer region of the ribosomal RNA genes (located at the Nor locus) was assayed in a collection of 411 accessions of Triticum tauschii from Turkey, USSR, Iran, Afghanisan, Pakistan, and China. Twenty rDNA genotypes were identified and it was demonstrated that T. tauschii accessions from the USSR and Iran have the highest diversity at the Nor locus. At least four of the rDNA genotypes were demonstrated to be alleles of a single major locus, in segregating F2 progeny analyses. The TaqI restriction fragment associated with rDNA genotype 7 was shown to be the same as the Nor-D3a allele present in all bread wheats (based on chromosome location and length of the intergenic spacer region). This genotype was significantly associated with T. t. ssp. strangulata, previously argued to be the donor of the D genome to hexaploid wheat. The Nor locus showed a high level of recombination with the 5SDna-2 locus, which was also located on chromosome 5D. The Nor locus is placed distal to the 5SDna-2 locus but proximal to the grain softness protein gene (XGsp) on the short arm of chromosome 5D.Key words: D genome, Nor-D3, rDNA polymorphism, chromosomal location.

A review of the occurrence of Grain softness protein-1 genes in wheat (Triticum aestivum L.)

2013 ◽  
Vol 83 (6) ◽  
pp. 507-521 ◽  
Author(s):  
Craig F. Morris ◽  
Hongwei Geng ◽  
Brian S. Beecher ◽  
Dongyun Ma
Keyword(s):  
Triticum Aestivum ◽  
Triticum Aestivum L ◽  
Grain Softness ◽  
Grain Softness Protein

scholarly journals Cloning of a wheat 15-kDa grain softness protein (GSP). GSP is a mixture of puroindoline-like polypeptides

1994 ◽  
Vol 223 (3) ◽  
pp. 917-925 ◽  
Author(s):  
Sadequr RAHMAN ◽  
Christopher J. JOLLY ◽  
John H. SKERRITT ◽  
Andrea WALLOSHECK
Keyword(s):  
Grain Softness ◽  
Grain Softness Protein

The Ha locus of wheat: Identification of a polymorphic region for tracing grain hardness in crosses

Genome ◽  
1999 ◽  
Vol 42 (6) ◽  
pp. 1242-1250 ◽  
Author(s):  
M Turner ◽  
Y Mukai ◽  
P Leroy ◽  
B Charef ◽  
R Appels ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Hexaploid Wheat ◽  
Aegilops Tauschii ◽  
Grain Hardness ◽  
High Sequence Identity ◽  
D Genome ◽  
Sequence Identity ◽  
Group 5 ◽  
Grain Softness ◽  
Puroindoline A

The grain softness proteins or friabilins are known to be composed of three main components: puroindoline a, puroindoline b, and GSP-1. cDNAs for GSP-1 have previously been mapped to group-5 chromosomes and their location on chromosome 5D is closely linked to the grain hardness (Ha) locus of hexaploid wheat. A genomic DNA clone containing the GSP-1 gene (wGSP1-A1) from hexaploid wheat has been identified by fluorescent in situ hybridization as having originated from the distal end of the short arm of chromosome 5A. A genomic clone containing the gene (wGSP1-D1) was also isolated from Aegilops tauschii, the donor of the D genome to bread wheat. There are no introns in the GSP-1 genes, and there is high sequence identity between wGSP1-A1 and wGSP1-D1 up to 1 kb 5' and 300 bp 3' to wGSP1-D1. However, regions further upstream and downstream of wGSP1-D1 share no significant sequence identity to corresponding sequences in wGSP1-A1. These regions therefore identified potentially valuable sequences for tracing the Ha locus through assaying polymorphic DNA sequences. The sequence from 300 to 500 bp 3' to wGSP1-D1 (wGSP1-D13) was mapped to the Ha locus in a mapping population. wGSP1-D13 was also tightly linked to genes for puroindoline a and puroindoline b which have been previously mapped to be at the Ha locus. In addition wGSP1-D13 was used to detect RFLPs between near isogenic soft and hard Falcon lines and in a random selection of soft and hard wheats.Key words: wheat, grain hardness, chromosome 5, puroindoline, GSP-1.

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