Transformation of Pinb-D1x to soft wheat produces hard wheat kernel texture

Abstract

Kernel hardness - a key quality trait of common wheat (Triticum aestivum L.) - is mainly conditioned by the Pina and Pinb genes. Mutation or deletion of Pina or Pinb increases kernel hardness, resulting in a hard wheat kernel texture. Here, Pinb-D1x gene was cloned from a hard wheat landrace Kashibaipi and transformed into a soft wheat cultivar Yangmai19 to assess its effect on kernel hardness and flour properties. PCR, RT-PCR and Western blot data confirmed the successful transformation and overexpression of Pinb-D1x gene in transgenic offsprings. The data of single kernel characterization system and scanning electron microscopy revealed that the introduction of Pinb-D1x in soft wheat increased the kernel hardness significantly and changed the internal structure of the kernel. Similarly, transgenic lines exhibited hard wheat like flour properties; flour whiteness and pasting temperature were significantly reduced in the transgenic lines, while the total protein content, damaged starch content, and compound parameter in the Mixograph tests (PT × TW value) showed a significant increase over the wildtype. The results showed that the transformation of the Pinb variants is a powerful strategy to alter the kernel hardness and flour properties in wheat breeding.