Effects of Overexpression of High Molecular Weight Glutenin Subunit 1Dy10 on Wheat Tortilla Properties

Abstract

Wheat (Triticum aestivum L.) flour properties necessary for optimal tortilla production have not been identified. Transgenic wheats (Triticum aestivum L.) overexpressing high molecular weight glutenin subunit (HMW-GS) 1Dy10 were used to make tortilla and their quality was evaluated. The level of HMW-GS 1Dy10 in flours derived from transgenic wheats was 2.5-5.8-fold greater than in controls. Polymeric proteins in the transgenic samples had a molecular weight distribution shifted toward larger polymers as indicated by increased levels of polymeric proteins present and greater M(w) averages of the largest fractions in the insoluble polymeric proteins. Dough derived from transgenic wheats had greater resistance to extension and lower extensibility than controls. Tortilla quality evaluation revealed that tortillas originated from transgenic wheats had decreased diameter, greater thickness and rupture force, and lower rollability scores and stretchability than controls. The presence of 1RS chromosomal translocations from rye (Secale cereale L.) in transgenic wheat decreased the negative effects of overexpression of HMW-GS 1Dy10, as tortillas made with this flour mostly exhibited quality properties similar to those made from control flour. Results suggested that the negative effects of overexpression of HMW-GS 1Dy10 on tortilla properties were derived from a nonideal gluten matrix formation.

Isolation and characterization of EMS-induced Dy10 and Ax1 high molecular weight glutenin subunit deficient mutant lines of elite hexaploid wheat (Triticum aestivum L.) cv. Summit

“…In support of this, over-expression of the Dx5 subunit in transgenic wheats yielded overly strong dough (Barro et al, 1997;Blechl et al, 2007). On the other hand, the overexpression of Dy10 gene also yielded very strong doughs, even though the molecular structure of Dy10 does not contain additional cysteine residue for crosslinking compared to other y-type subunits (Blechl et al, 2007;Gadaleta et al, 2008;Pierucci et al, 2009). Thus, not only the composition but also the level of expression of the different HMW-GS genes is important for determining dough quality.…”

“…Flours from transgenic wheat lines overexpressing Dy10 yielded stronger doughs with longer development time (Pierucci et al, 2009;Wang et al, 2011). Similarly, flours from transgenic wheat lines overexpressing Ax1 yielded stronger doughs (Popineau et al, 2001;Vasil et al, 2001;Wang et al, 2011).…”

Effect of High‐Molecular‐Weight Glutenin Subunit Allelic Composition on Wheat Flour Tortilla Quality

“…Payne et al (1987) reported that 5 + 10 at the Glu-D1 locus contributed to dough strength, whereas IPP content is one of the major determinants of dough strength and showed higher correla-tions than protein content to bread loaf volume, bake mix time, and mixing tolerance (Bean et al 1998;Park et al 2006). A strong negative correlation has been shown between IPP and tortilla properties (Pierucci et al 2009;Barros et al 2010).…”

Relationship Between Objective and Subjective Wheat Flour Tortilla Quality Evaluation Methods

“…Tortilla extensibility is believed to be influenced to a large extent by gliadin proteins (Mondal et al 2008), whereas glutenin is believed to primarily influence tortilla resistance to extension (force to extend). On the other hand, Pierucci et al (2009) reported that overexpression of high molecular weight glutenin subunit in wheat resulted in tortillas that required more force to extend and had reduced shelf stability. Mondal et al (2008) recently demonstrated that deletion of specific high molecular weight glutenin genes improved tortilla shelf stability as well as diameter, by altering the effective ratio of glutenins to gliadins.…”

“…Mondal et al (2008) recently demonstrated that deletion of specific high molecular weight glutenin genes improved tortilla shelf stability as well as diameter, by altering the effective ratio of glutenins to gliadins. On the other hand, Pierucci et al (2009) reported that overexpression of high molecular weight glutenin subunit in wheat resulted in tortillas that required more force to extend and had reduced shelf stability. This phenomenon needs further investigation.…”