loading page

New Insights to Zinc Biofortification of Wheat: Opportunities to Fine-tune Zinc Uptake, Remobilization and Grain Loading
  • +3
  • Chandima Kamaral,
  • Stephen Neate,
  • Niroshini Gunasinghe,
  • Paul Milham,
  • David Paterson,
  • Saman Seneweera
Chandima Kamaral
University of southen Queensland

Corresponding Author:[email protected]

Author Profile
Stephen Neate
University of Southern Queensland
Author Profile
Niroshini Gunasinghe
University of southen Queensland
Author Profile
Paul Milham
Western Sydney University Hawkesbury Institute for the Environment
Author Profile
David Paterson
Australian Synchrotron Holding Company Pty Ltd
Author Profile
Saman Seneweera
University of southen Queensland
Author Profile

Abstract

Wheat contains low grain zinc (Zn) due to its genetics and the physiochemical properties of the soil in which it is grown. Consequently, where wheat forms a major part of the human diet, bioavailable Zn is below dietary requirements. Understanding the regulation of genes responsible for cellular Zn-transport, particularly those responsible for the control of the biosynthesis pathway of nicotianamine, provides an opportunity to increase Zn loading into the grain. Decreasing the levels of phytic acid, an inhibitor of Zn absorption in humans, provides another opportunity to increase the bioavailability of grain Zn. Synchrotron X-ray fluorescence microscopy clearly demonstrated that the crease region of the wheat grain is a major bottleneck to Zn loading in the endosperm. Higher expression of Zn transporter families, particularly metal tolerance proteins and yellow stripe like transporter families in the aleurone layer are also likely to play a major role in determining grain Zn content. Finally, anatomical barriers in the vascular region at the base of the wheat grain are a major limitation to Zn loading. Modification of any of these traits through traditional plant breeding or gene editing provides an opportunity to increase the Zn concentration in wheat grain.