Expression of Phytase Gene in Wheat Endosperm Increases Availability of Iron and Zinc

Phytate is a major component of wheat seeds which chelates metal ions, thus, reducing the nutritional value of wheat grains. Transgenic plants expressing heterologous phytase are expected to have enhanced degradation of phytic acid and are hypothesized to have increased mineral nutrients in their seeds.

Nabeela Abid, from the Forman Christian College in Pakistan, together with a team of researchers developed transgenic wheat expressing the Aspergillus japonicus phytase gene (phyA) in its endosperm. The transgenic lines exhibited 18–99 % increase in phytase activity and as high as 76% reduction of phytic acid in seeds, with the lowest phytic acid content observed in chapatti. Analysis revealed a two-fold to nine-fold increase in expression as compared to the controls.

There was no significant difference in nutrient composition between transgenic and non-transgenic seeds. However, assays for iron and zinc in the dough and bread made from the transgenic lines revealed a significant increase in iron and zinc contents.

For more information on this study, read the article in Transgenic Research.