Mineral element composition in grain of awned and awnletted wheat (Triticum aestivum L.) cultivars : tissue-specific iron speciation and phytate and non-phytate ligand ratio

Pongrac, Paula (author), Arčon, Iztok (author), Castillo Michel, Hiram (author), Vogel-Mikuš, Katarina (author)

In wheat (Triticum aestivum L.), the awns—the bristle-like structures extending from lemmas—are photosynthetically active. Compared to awned cultivars, awnletted cultivars produce more grains per unit area and per spike, resulting in significant reduction in grain size, but their mineral element composition remains unstudied. Nine awned and 11 awnletted cultivars were grown simultaneously in the field. With no difference in 1000-grain weight, a larger calcium and manganese—but smaller iron (Fe) concentrations—were found in whole grain of awned than in awnletted cultivars. Micro X-ray absorption near edge structure analysis of different tissues of frozen-hydrated grain cross-sections revealed that differences in total Fe concentration were not accompanied by differences in Fe speciation (64% of Fe existed as ferric and 36% as ferrous species) or Fe ligands (53% were phytate and 47% were non-phytate ligands). In contrast, there was a distinct tissue-specificity with pericarp containing the largest proportion (86%) of ferric species and nucellar projection (49%) the smallest. Phytate ligand was predominant in aleurone, scutellum and embryo (72%, 70%, and 56%, respectively), while nucellar projection and pericarp contained only non-phytate ligands. Assuming Fe bioavailability depends on Fe ligands, we conclude that Fe bioavailability from wheat grain is tissue specific.

• Language: English
• Keywords: biofortification, phytate, iron, awn, X-ray fluorescence, X-ray absorption spectrometry, phosphorus, sulphur, nicotianamine
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2020
• Number of pages: 14 str.
• Numbering: Vol. 9, iss. 1, art. 79
• PID: 20.500.12556/RUL-133267
• UDC: 53
• ISSN on article: 2223-7747
• DOI: 10.3390/plants9010079
• COBISS.SI-ID: 33018919
• Publication date in RUL: 19.11.2021

Record is a part of a journal

• Title: Plants
• Shortened title: Plants
• Publisher: MDPI
• ISSN: 2223-7747
• COBISS.SI-ID: 523345433

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 08.01.2020