Coexpression of the High Molecular Weight Glutenin Subunit 1Ax1 and Puroindoline Improves Dough Mixing Properties in Durum Wheat (Triticum turgidum L. ssp. durum)

Abstract

Wheat end-use quality mainly derives from two interrelated characteristics: the compositions of gluten proteins and grain hardness. The composition of gluten proteins determines dough rheological properties and thus confers the unique viscoelastic property on dough. One group of gluten proteins, high molecular weight glutenin subunits (HMW-GS), plays an important role in dough functional properties. On the other hand, grain hardness, which influences the milling process of flour, is controlled by Puroindoline a (Pina) and Puroindoline b (Pinb) genes. However, little is known about the combined effects of HMW-GS and PINs on dough functional properties. In this study, we crossed a Pina-expressing transgenic line with a 1Ax1-expressing line of durum wheat and screened out lines coexpressing 1Ax1 and Pina or lines expressing either 1Ax1 or Pina. Dough mixing analysis of these lines demonstrated that expression of 1Ax1 improved both dough strength and over-mixing tolerance, while expression of PINA detrimentally affected the dough resistance to extension. In lines coexpressing 1Ax1 and Pina, faster hydration of flour during mixing was observed possibly due to the lower water absorption and damaged starch caused by PINA expression. In addition, expression of 1Ax1 appeared to compensate the detrimental effect of PINA on dough resistance to extension. Consequently, coexpression of 1Ax1 and PINA in durum wheat had combined effects on dough mixing behaviors with a better dough strength and resistance to extension than those from lines expressing either 1Ax1 or Pina. The results in our study suggest that simultaneous modulation of dough strength and grain hardness in durum wheat could significantly improve its breadmaking quality and may not even impair its pastamaking potential. Therefore, coexpression of 1Ax1 and PINA in durum wheat has useful implications for breeding durum wheat with dual functionality (for pasta and bread) and may improve the economic values of durum wheat.

Overexpression of Avenin-Like b Proteins in Bread Wheat (Triticum aestivum L.) Improves Dough Mixing Properties by Their Incorporation into Glutenin Polymers

“…Relationships between Mixograph parameters and dough viscoelasticity have been studied in details [40] and associations of these parameters with other wheat quality traits were also discussed previously [43]. In general, MPW and MRW positively correlated with dough resistance to extension [21], whereas WS and MTxW negatively and positively correlated with tolerance to over-mixing, respectively [40], [44], [45]. Parameters of the curve height values (MLV, MPV, MRV and MTxV) positively correlated with dough elasticity [39].…”

Development of Marker-free TaGlu-Ax1 Transgenic Rice Harboring a Wheat High-molecular-weight Glutenin Subunit (HMW-GS) Protein

“…7). However, co-expression of TaGlu-Ax1 and PINA in durum wheat is increased dough strength and resistance to extension than lines expressing TaGlu-Ax1 or Pina [19].…”

“…Although co-expression of TaGlu-Ax1 and PINA in durum wheat have combined effects on dough mixing behaviors with a better dough strength and resistance to extension than those from lines expressing TaGlu-Ax1 or Pina [19], the expression of TaGlu-Ax1 is no doubt to influence the processing properties. Overexpression of HMW-GS Ax1 in several durum wheat cultivars resulted in increased dough strength [13].…”

Pentaploid Wheat Hybrids: Applications, Characterisation, and Challenges

“…Improving quality characteristics is one of the primary concerns when developing commercial varieties suitable for human and animal consumption. For example, grain protein content, protein quality, flour color, and grain texture are key quality criteria when developing wheat varieties for bread and pasta production (Sissons, 2008). …”

“…Interspecific hybridisation involving hexaploid/tetraploid crosses has demonstrated that the resultant progeny have significantly improved grain weight, grain diameter, and grain yield (Kalous et al, 2015). Furthermore, it was suggested that introducing 1D chromosome segments and their associated protein products would improve the bread making quality of durum wheat (Sissons, 2008). Wang et al (2005) indicated that recombinant allohexaploid lines, which had retained all seven copies of the D genome chromosomes, had enhanced protein content compared to their hexaploid parental lines.…”