Quality and Agronomic Effects of Three High‐Molecular‐Weight Glutenin Subunit Transgenic Events in Winter Wheat

Abstract

Quality and agronomic effects of three transgenic high molecular weight glutenin subunit (HMW‐GS) events were characterized in advanced‐generation breeding lines of hard winter wheat (Triticum aestivum L.) in three Nebraska crop years. Two of the transgenic events studied, Dy10‐E and B52a‐6, overexpress HMW‐GS 1Dy10, while the third event, Dx5 +Dy10‐H, overexpresses HMW‐GS 1Dx5 and, to a much lesser extent, 1Dy10. In addition, novel proteins possessing solubility characteristics defined as HMW‐GS were present in Dx5+Dy10‐H and B52a‐6. Average grain yield of lines derived from the three transgenic events was statistically lower than that of a group of control cultivars and advanced breeding lines, but not lower than the mean values of respective nontransgenic siblings. Grain hardness was influenced by one of the events. Dx5+Dy10‐H produced harder kernels than controls, its nontransgenic siblings, and the two additional transgenic events. All three events produced doughs with unusual mixing properties, although not likely to be directly useful in commercial applications. As a consequence, loaf volumes were depressed to variable degrees by the three events. The results indicated that over‐expression of HMW‐GS could eventually lead to improved breadmaking quality by optimizing the level of overexpression or by development and characterization of additional events.

Transformation of the US bread wheat ‘Butte 86’ and silencing of omega-5 gliadin genes

“…42 While these studies have shown that different HMW-GS can have distinct effects on dough mixing properties, ultimately it is desirable to introgress transgenes from Bobwhite into advanced cultivars by conventional breeding to truly assess the effects of the transgenes on flour quality. 43,44 Only a few transgenic studies using Bobwhite have focused on gluten proteins from the more complex LMW-GS and gliadin families. Masci et al 45 overexpressed a LMW-GS and Gil-Humanes et al 46 used RNA interference to silence gamma gliadin genes.…”

The Role of Empirical Rheology in Flour Quality Control

“…The major advantage of the Mixograph method is that it is not time consuming and it requires small amount of flour sample (2g, 10 g and 35 g depending on mixing bowls). Therefore, this method remained traditional among breeders, who handle with small amounts of sample, and for whom this method was initially designed (Graybosch et al, 2011).…”

Variant high-molecular-weight glutenin subunits arising from biolistic transformation of wheat

“…This line was crossed with Great Plains winter wheats and further characterized in those backgrounds (Graybosch et al, 2011). Seeds from these derived lines can contain seed storage proteins other than those in the transformed cultivar 'Bobwhite' (BW in Fig.…”

“…The derivation and characterization of those lines are described in Graybosch et al (2011). The original 'Bobwhite' transformant was co-transformed by Ubi::BAR and a plasmid carrying the native gene encoding 1Dy10.…”