Physiological and genetic control of phytic acid in diverse sets of wheat (Triticum aestivum L.)

Lozano Guajardo, Josefina Concepcion (2021) Physiological and genetic control of phytic acid in diverse sets of wheat (Triticum aestivum L.). PhD thesis, University of Nottingham.

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Abstract

Phytic acid (PA) is the main source of phosphorus storage in plants. Since the molecule has a negative charge, it creates complexes with important minerals such as Cu, Zn, Co, Mn, Mg, Fe and Ca. It is therefore regarded as an antinutrient because monogastric animals do not have the necessary enzymes to break the bonds. This leads to major issues such as micronutrient deficiencies in the population, all the unused phosphorus is excreted and eventually reaches water bodies causing eutrophication. Up to 60-85 % of P from soil is stored as PA in grains, hence all this P is removed from the soil at harvest and this removed P has a cost, which has been estimated in billions. Hence, even small reductions in the PA concentrations could represent more efficient and nutritious crops as well as important money savings.

In this study we analysed wheat samples grown in a hydroponic system and evaluated the effect of P and Zn treatments on its concentration in leaf and grain (Chapter 2). Treatments had significant effect over PA and other mineral concentrations in grain and leaf samples. We observed significant relationships between leaf and grain PA and mineral concentrations indicating that some predictions could be made from a single and simple analysis in leaves. In Chapters 3 and 4 we describe a huge variability in PA concentrations in diverse genotypes and environments. We found significant differences between the genotypes, environments and their interactions. Moreover, phytate to mineral molar ratios were calculated and the potential impact over the bioavailability of Ca, Fe and Zn is discussed. The results obtained here highlight the importance of PA determination as an important trait to be looked at when breeding or searching for mineral enhanced varieties. As we observed, some genotypes with high concentrations of Fe and Zn had also high concentrations of PA. High PA ratios will inevitably affect the bioavailability of Fe and Zn.

A great amount of work has been done over the past years, but there are still gaps of knowledge to be filled, such as the transport and loading of P into seeds, the genetic control of P translocation from vegetative tissues to seed, the heritability of P and PA traits, among others. This work aims to set the basis for further and more specialized studies looking into developing new low phytate varieties.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Graham, Neil S
Broadley, Martin R
Keywords: Phytic acid, Plant mineral nutrition, Hydroponics, Phosphorus, Wheat, Watkins, Hostile
Subjects: S Agriculture > SB Plant culture
Faculties/Schools: UK Campuses > Faculty of Science > School of Biosciences
Item ID: 64592
Depositing User: Lozano Guajardo, Josefina
Date Deposited: 31 Jul 2021 04:40
Last Modified: 31 Jul 2021 04:40
URI: http://eprints.nottingham.ac.uk/id/eprint/64592

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