28 Feb 2016

Genetic Control of Apigenin di-C-glycosides Biosynthesis in Bread Wheat (Triticum Aestivum L.) Grain and their Potential Role as Yellow Pigments in Asian Alkaline Noodles

Grace Yasmein Wijaya, July 2012
The University of Adelaide

Abstract
The aim of this project was to discover new information on the role of the 2 types of apigenin di-C-glycosides (ACGs) in yellow alkaline noodle (YAN) colour and genetic regulation of their biosynthesis. To achieve this aims: genetic variation in grain ACG traits in bread wheat and related species was surveyed, the quantitative contribution of ACG to the yellow colour of YAN was determined and compared to lutein, QTL for ACG content and composition were located, and candidate genes associated with variation in ACG composition identified.

Substantial variation in both grain ACG content and the ratio, ACG1/ACG2, were identified within bread wheat cultivars and related species. Genotype controlled the major portion of the variation. ACG content appeared to be a multigenic trait whereas variation in ACG1/ACG2 was associated with a limited number of chromosomes, in particular chromosomes 1B, 7B and 7D. Elimination of chromosome 7B in Chinese Spring 7B nullisomic-tetrasomic lines resulted in an increase in ACG1/ACG2, i.e. a relative increase in the glucose-containing isomer, possibly indicating the presence of a C-glycosyltransferase on 7B with specificity for UDP-galactose. Major QTL for ACG1, ACG2 and ACG1/ACG2 were detected near Xwmc76 on chromosome 7BS in a Sunco/Tasman population. Based on synteny with the rice genome, a candidate glycosyltransferase was identified in the region of the ACG ratio QTL.

ACG contributed a small but significant part of the yellow colour specifically developed in the presence of alkali. Whilst it should be possible to manipulate both ACG content and composition traits through breeding, improvement in colour for YAN will be limited to some extent by the available genetic variation and the location of ACG in grain tissues that are largely removed during milling.

Share this article on:

Related Article


Back to Top