The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China.
College of Life Science and Health, Wuhan University of Science and Technology, Wuhan, 430065, China.
BMC Plant Biol. 2019 Apr 4;19(1):126. doi: 10.1186/s12870-019-1734-x.
Durum wheat is considered not suitable for making many food products that bread wheat can. This limitation is largely due to: (i) lack of grain-hardness controlling genes (Puroindoline a and b) and consequently extremely-hard kernel; (ii) lack of high- and low-molecular-weight glutenin subunit loci (Glu-D1 and Glu-D3) that contribute to gluten strength. To improve food processing quality of durum wheat, we stacked transgenic Pina and HMW-glutenin subunit 1Ax1 in durum wheat and developed lines with medium-hard kernel texture.
Here, we demonstrated that co-expression of Pina + 1Ax1 in durum wheat did not affect the milling performance that was enhanced by Pina expression. While stacking of Pina + 1Ax1 led to increased flour yield, finer flour particles and decreased starch damage compared to the control lines. Interestingly, Pina and 1Ax1 co-expression showed synergistic effects on the pasting attribute peak viscosity. Moreover, Pina and 1Ax1 co-expression suggests that PINA impacts gluten aggregation via interaction with gluten protein matrix.
The results herein may fill the gap of grain hardness between extremely-hard durum wheat and the soft kernel durum wheat, the latter of which has been developed recently. Our results may also serve as a proof of concept that stacking Puroindolines and other genes contributing to wheat end-use quality from the A and/or D genomes could improve the above-mentioned bottleneck traits of durum wheat and help to expand its culinary uses.
杜伦小麦被认为不适合制作许多面包小麦可以制作的食品。这种局限性主要归因于：（i）缺乏谷物硬度控制基因（Puroindoline a 和 b），因此导致极硬的内核；（ii）缺乏高和低分子量谷蛋白亚基基因座（Glu-D1 和 Glu-D3），这些基因座有助于面筋强度。为了提高杜伦小麦的食品加工质量，我们在杜伦小麦中堆叠转基因 Pina 和高分子量谷蛋白亚基 1Ax1，并开发出具有中硬内核质地的品系。
在这里，我们证明了 Pina + 1Ax1 在杜伦小麦中的共表达并没有影响到由 Pina 表达增强的磨粉性能。虽然 Pina + 1Ax1 的堆叠导致面粉产量增加，面粉颗粒更细，淀粉损伤减少，但与对照品系相比。有趣的是，Pina 和 1Ax1 的共表达对糊化特性峰值粘度表现出协同作用。此外，Pina 和 1Ax1 的共表达表明 PINA 通过与谷蛋白基质相互作用影响谷蛋白聚集。
本文的结果可能填补了极硬杜伦小麦和最近开发的软核杜伦小麦之间的谷物硬度差距。我们的结果也可以作为一个概念验证，即从 A 和/或 D 基因组中堆叠有助于小麦最终用途质量的 Puroindolines 和其他基因，可以改善杜伦小麦的上述瓶颈特性，并有助于扩大其烹饪用途。
