Journal article
Inositol phosphates from barley low-phytate grain mutants analysed by metal-dye detection HPLC and NMR
Inositolphosphates from barley low-phytate grain mutants and their parent variety were analysed by metal-dye detection HPLC and NMR. Compound assignment was carried out by comparison of retention times using a chemical hydrolysate of phytate [Ins(1,2,3,4,5,6)P(6)] as a reference; Co-inciding retention times indicated the presence of phytate, D/L-Ins(1,2,3,4,5)P(5), Ins(1,2,3,4,6)P(6), D/L-(1,2,4,5,6)P(5), D/L-(1,2,3,4)P(4), D/L-Ins(1,2,5,6)P(4) and D/L-Ins(1,4,5,6)P(4) in PLP1B mutants as well as the parent variety.
In grain extracts from mutant lines PLP1A, PLP2A and PLP3A unusual accumulations of D/L-Ins(1,3,4,5)P(4) were observed whereas phytate and the above-mentioned inositol phosphates were present in relatively small amounts. Assignment of D/L-Ins(1,3,4,5)P(4) was corroborated by precise co-chromatography with a commercial Ins(1,3,4,5)P(4) standard and by NMR spectroscopy.
Analysis of inositol phosphates during grain development revealed accumulation of phytate and D/L-Ins(1,3,4,5)P(4), which suggested the tetrakisphosphate compound to be an intermediate of phytate synthesis. This assumption was strengthened further by phytate degradation assays showing that D/L-Ins(1,3,4,5)P(4) did not belong to the spectrum of degradation products generated by endogenous phytase activity.
Metabolic scenarios leading to accumulation of D/L-Ins(1,3,4,5)P(4) in barley low-phytate mutants are discussed.
Language: | English |
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Publisher: | Portland Press Ltd. |
Year: | 2001 |
Pages: | 473-480 |
ISSN: | 14708728 and 02646021 |
Types: | Journal article |
DOI: | 10.1042/0264-6021:3540473 |
ORCIDs: | 0000-0001-6169-2504 |
6-Phytase Chromatography, High Pressure Liquid Coloring Agents Ether Grain filling Hordeum Hordeum vulgare Inositol Phosphates Inositol phosphate kinase Isomerism Magnetic Resonance Spectroscopy Metals Phytase Phytic Acid Seed-specific Trichloroacetic Acid inositol-1,3,4,5-tetrakisphosphate