low molecular weight glutenin subunits and gliadins in 137 double haploid wheat lines derived from a...

T: 051 401 9111 [email protected]

M.T. LABUSCHAGNE and A. VAN BILJON

Department of Plant

Sciences, University of the Free State, P.O. Box

339, Bloemfontein 9300, South Africa

Email: [email protected]

LOW MOLECULAR WEIGHT GLUTENIN SUBUNITS

AND GLIADINS IN 137 DOUBLE HAPLOID WHEAT LINES DERIVED FROM A

CROSS BETWEEN KARIEGA AND AVOCET

INTRODUCTION

the protein of maize is deficient in two essential amino acids, lysine and tryptophan

They are controlled by Gli loci on the short arms of chromosomes 1 and 6

γ and ω = 1A, 1B, 1D Gli-A1, Gli-B1, Gli-D1 α and β = group 6 chromosomes, Gli-A2, Gli-B2, Gli-D2

Wheat gliadins are a highly polymorphic group of seed storage proteins

From Shewry and Lookhart (2003)

Gliadin extract gives ω5, ω1,2, α and γ gliadins

Glutenin extract gives glutenin bound ω extracts and HMW and LMW subunits

Genes encoding LMW GS (Glu-3) are linked to genes (Gli-1) encoding ω and γ gliadins

Most wheat cultivars show similar overall patterns of gliadin and glutenin subunits with characteristic regions for

each type

AIM OF THE STUDY

To study low molecular weight glutenins and gliadins in a DH population of a cross between Kariega and Avocet

A

AIM OF STUDY

To study low molecular weight

glutenins and gliadins in a DH population of a cross between

Kariega and Avocet


Materials and methods

Double haploid wheat population, developed with wheat x maize crosses using wheat x maize crosses

Avocet x Kariega: 137 DH’s developed from F2 material

Kariega = hard red South African bread wheat with excellent quality

Avocet = standard white Australian spring wheat


Materials and methods

Protein extraction for RP-HPLC using method of Wieser et al. (1998)

First gliadin extraction with 70% ethanol

RP-HPLC with C18 column

Glutenin extraction with 50% propan-1-ol, urea and DTT and 4-

vinylpyridine


Results

Gliadin profile of Avocet

Gliadin profile of Kariega

ωωω ωωα ωωγ

ωωω ωωα ωωγ

GLIADIN PEAK AREA (%) OF PARENTS AND THE DH POPULATION

Name P20.8 P21.4 P22.3 P23 p24 p25.1 p26 p265 p27 p275 p28.6 p31 p345 p36

Avocet 2.91 6.13 0.00 0.00 2.4 0.00 13.12 10.35 4.25 8.00 2.66 18.47 6.89 1.27

Kariega 3.99 3.63 1.94 1.3 2.3 2.65 8.67 7.89 4.02 7.49 0.00 18.49 5.03 1.33

DH 3.44 3.86 1.28 1.77 2.36 0.900 13.16 11.29 5.13 6.69 2.59 16.57 6.77 1.74

ω α γ


Gliadins

ω peak 22.3 was absent in Avocet but was present in 50 of 137 DH’s

ω peak 23 was absent in Avocet but was present in 127 of 137 DH’s

α peak 25.1 was absent in Avocet, but was present in only 41 of 137 DH’s

8/14/2012


Gliadins

8/14/2012

α peak 28.6 was absent in Kariega, but was present in 118 of 137 DH’s

α peak 26 was much higher in Avocet (13.12) than in Kariega (8.67) but the DH average was 13.16, like the Avocet parent

α peak 26.5 was higher for the DH average (11.29) than either parent Avocet (10.35) and Kariega (7.89)


Gliadins

8/14/2012

α peak 27.5 was lower for the DH average (6.69) than for either parent Avocet (8) or Kariega (7.49)

The other peaks for DH averages were close to the average of the two parents

Highly significant (P≤0.0001) correlations between gliadins

Characteristic1 Characteristic2 Correlation

P20.8 (ω) P21.4(ω) -0.693

P20.8(ω) P22.3(ω) -0.432

P21.4 (ω) P22.3 (ω) 0.872

P22.3 (ω) P24 (α) 0.376

P22.3 (ω) P31 (α) -0.376

P23 (α) P36 (γ) 0.346

P25.1 (α) P26 (α) -0.886

P27.5 (α) P28.6 (α) -0.685

8/14/2012

Avocet glutenins

HMW HM H

HMW HMW

Kariega glutenins

HMW glutenins LMW glutenins

LMW glutenins HMW glutenins

0, 7+8, 2+12

2*, 17+18, 2+12

LMW GLUTENIN PEAKS (% AREA) OF PARENTS AND THE DH POPULATION

gl26 gl27 gl28.5 gl28.8 gl29.4 gl30 gl32 gl33.3 Avocet 6.72 37.05 5.17 3.63 3.60 6.06 3.22 4.03 Kariega 5.96 33.40 4.90 3.46 3.71 5.93 3.18 2.34 DH 9.79 28.97 4.24 4.03 3.34 5.34 3.98 5.41


LMW glutenins

8/14/2012

These subunits were more difficult to score than the gliadins

Peak 26 average of the DH was much higher (9.79) than that of either Avocet (6.72) or Kariega (5.96)

Peak 27 average of the DH was much lower (28.97) than either Avocet (37.05) or Kariega (33.4)


LMW glutenins

8/14/2012

Peak 33.3 DH average (5.41) was much higher than that of either Avocet (4.03) or Kariega (2.34)



Peak 26 Peak 27 -0.372

Peak 28.8 Peak 29.4 -0.318

Peak 28.8 Peak28.5 0.243

Peak 28.5 Peak 29.4 -0.248

Peak 29.4 Peak 28.8 -0.318

Peak 28.8 Peak 30 -0.274

Highly significant (P≤0.01) correlations between LMW glutenins



Gliadin peak 26.5 Glutenin peak 27 -0.229

Gliadin peak 27.5 Glutenin peak 28.5 0.253

Gliadin peak 25.1 Glutenin peak 28.5 -0.273

Gliadin peak 34.5 Glutenin peak 33 0.419

Highly significant (P≤0.01) correlations between LMW glutenins and gliadins

8/14/2012

DISCUSSION AND CONCLUSIONS

Peak 22.3 absent in Avocet was present in 36% of the DH population

Peak 23 absent in Avocet was present in 93% of DH population

For the gliadins three peaks were absent in Avocet which were in Kariega, and one was absent in Kariega which was present in Avocet

Peak 28.6 absent in Kariega was present in 86% of the DH population

Peak 25.1 absent in Avocet was present in 30% of DH population

Peaks 25.1 and 26 were highly negatively correlated (-0.886) indicating that the presence of one lead to the supression of

the other

Peaks 20.8 and 21.4; and 27.5 and 28.6 were also highly negatively correlated (-0.693 and -0.685) indicating that the

presence of one usually supressed the expression of the other

Peak 21.4 and 22.3 almost always occurred together and were correlated r=0.872

In four of the peaks the values were higher for the DH population than that of either parent, and for the four other

peaks they were lower than for either parent

There were some significant correlations within the LMW glutenins and between LMW glutenins and the gliadins, but

the values were very low

Eight clear LMW glutenin peaks were seen in all material

The DH population expressed the peak missing in either parent to a much higher extent than expected in two cases and much

lower than expected in two cases. One can speculate on the reason for this

Both the glutenin and the gliadin peaks of the DH population were not intermediate between that of the parents, indicating some interaction between genes coding for these loci

Thank you!

low molecular weight glutenin subunits and gliadins in 137 double haploid wheat lines derived from a...

Technology

gliadins peak

dhs peak

avocet parent peak

lmw glutenins peak

gliadin peak area

dh gliadins

parent avocet

avocet whichwere