Origin and practical significance of the sticky dough factor in 1BL/1RS wheats

Abstract

When translocated into wheat, the short arm of the 1R chromosome of rye carries with it linked resistance genes to powdery mildew, stripe rust, leaf rust and stem rust. The translocation is also reported to increase yield potential of hard wheats. However, many doughs made from some 1BL/1RS hard wheats are unacceptable for breadmaking purposes because of excessive stickiness and mixing intolerance. 1BL/1RS wheats may be sticky because of: the inheritance of secalin proteins from rye and absence of key glutenin subunits; higher amounts and/or differences in the composition of cell wall polysaccharides, b-glucans and pentosans; and/or the presence of a ferulic acid ester moiety residing with the water-soluble fraction of 1BL/1RS flours. None of these hypotheses has been proven or disproven, to date, as a cause of excessive stickiness. Investigators have found that 1BL/1RS doughs are not uniformly sticky and are in some instances less sticky than non-1BL/1RS doughs. Significant genotype-environment interactions have been reported for dough stickiness and flour quality characteristics of 1BL/1RS wheats. Investigators have generally failed to find significant differences in the breadmaking performance of 1BL/1RS and non-1BL/1RS hard wheats despite a report that 1BL/1RS doughs break down and soften during high-speed mixing. The 1BL/1RS translocation has been shown to reduce cookie spread of soft wheat flours but has no deleterious effects on cake volume or texture.

Effect of Environmental Stress during Grain Filling on the Soluble Proteome of Wheat (Triticum aestivum) Dough Liquor

“…Four bread wheat cultivars were selected for comparison: the soft milling cultivar Beaver and the hard milling cultivars Spark, Rialto, and Soissons. Two of these, Beaver and Rialto, have a 1BL/1RS chromosome translocation, which is often associated with dough stickiness and hence poor breadmaking performance (18). These lines were grown in the field and in polytunnels with hot/dry or cold/wet regimes imposed during the grain filling period (from 14 days after 50% anthesis), milled, and used to prepare aqueous dough fractions for analysis.…”

Genomic and functional genomics analyses of gluten proteins and prospect for simultaneous improvement of end-use and health-related traits in wheat

“…The Sec-1 locus of 1RS harbors the genes that encode γ-and ω-secalins, which resemble wheat γ-gliadins and ω-gliadins, respectively (Chai et al 2005;Clarke et al 1996). Although these secalins have been found to negatively affect gluten, dough and end-use properties by many genetic and rheological studies (Barbeau et al 2003;Dhaliwal et al 1990), the precise copy numbers of γ-and ω-secalin genes carried by Sec-1 are still not well understood, neither is it clear how many distinct γ-and ω-secalins are accumulated in the grains of 1BL/1RS wheat varieties. Nevertheless, three studies have estimated the size of Sec-1 to be at least 145 kb or 195 kb and contained 15 or 18 ω-secalin genes (Clarke et al 1996;Li et al 2016;Yamamoto and Mukai, 2005).…”

Molecular identification of ω-secalin gene expression activity in a wheat 1B/1R translocation cultivar

“…The expression of ω-secalin genes has an adverse effect on the processing quality of wheat 1B/1R Translocation Lines (Barbeau et al 2003). Although the ω-secalin gene family has 15 copies (Yamamoto and Mukai 2005), only four ω-secalin gene family members are expressed in 1B/1R translocation lines with 1RS from 'Petkus' rye from the present study, it can be concluded that only.…”

“…The poor quality of cultivars with 1BL/1RS translocations is thought to be partially caused by the expression of ω-secalins encoded by genes on 1RS (Barbeau et al 2003), which are a family of small, highly water-soluble monomeric proteins related to wheat ω-gliadin (Dhaliwal et al 1990;Graybosh et al 1990;Lookhart et al 1991;Hussain and Lukow 1994). The ω-secalin gene family has 15 copies that are arranged in a head-to-tail fashion (Clarke et al 1996;Clarke and Appels 1999;Yamamoto and Mukai 2005).…”