Publication no. C-1999-1006-04R |  VIEW ARTICLE

Allelic Variation at Glu-D1 Locus for High Molecular Weight (HMW) Glutenin Subunits: Quantification by Multistacking SDS-PAGE of Wheat Grown Under Nitrogen Fertilization (1).

J. Zhu (2), K. Khan (2,3), S. Huang (4), and L. O'Brien (5). (1) Published with the approval of the Director, Agricultural Experimental Station, North Dakota State University, Fargo, ND 58105. (2) Department of Cereal Science, North Dakota State University, Fargo, ND 58105. (3) Corresponding author. E-mail: <kkhan@prairie.nodak.edu> (4) Bread Research Institute of Australia, PO Box 7, North Ryde, NSW 2113, Australia. (5) Plant Breeding Institute, University of Sydney, Narrabri, NSW 2390, Australia. Cereal Chem. 76(6):915-919. Accepted July 29, 1999. Copyright 1999 American Association of Cereal Chemists, Inc.

Two biotypes of an Australian wheat cultivar, Warigal, differing only in the Glu-D1 high molecular weight (HMW) glutenin subunits 5+10 and 2+12 were used in this study. The objective was to examine the effects of nitrogen fertilization and allelic variation at the Glu-D1 locus on the characteristics of glutenin polymers. Unreduced proteins containing the SDS-soluble glutenins and the other protein classes were analyzed by multistacking SDS-PAGE which separates the glutenin into six distinctly different-sized aggregates. The results showed that nitrogen fertilization significantly increased protein quantity, ratio of polymers to monomeric proteins, and sizes of SDS-soluble glutenins. Nitrogen fertilization affected the proportions of HMW subunits in both SDS-soluble and SDS-insoluble glutenin polymers and the ratio of x to y subunits in SDS-insoluble glutenin polymers. Nitrogen fertilization, however, did not cause a significant change in ratio of SDS-soluble to SDS-insoluble glutenins. SDS-insoluble glutenins had a greater ratio of HMW to LMW and x to y subunits, especially with a higher increase of 1Dx subunits, than SDS-soluble glutenins. The HMW/LMW subunit ratio and the x/y subunit ratio may be used to predict sizes of glutenin polymers. The biotype with 5+10 subunits had a greater x/y subunit ratio in the SDS-insoluble glutenins than the 2+12 type. A greater proportion of subunit 5 was formed than subunit 2 in the SDS-insoluble glutenin polymers. Both nitrogen fertilization and allelic variation at Glu-D1 loci could affect the characteristics of glutenin polymers.