Cell wall degradation is required for normal starch mobilisation in barley endosperm
| Autor: | Vasilios M. E. Andriotis, Alison M. Smith, Robert A. Field, Michael D. Rugen, Elaine Barclay, Martin Rejzek |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0106 biological sciences
0301 basic medicine Glycoside Hydrolases Starch Immunoblotting 01 natural sciences Article Endosperm Cell wall 03 medical and health sciences chemistry.chemical_compound Sugar Alcohols Cell Wall Manchester Institute of Biotechnology Aleurone Botany Arabinoxylan Limit dextrinase Amylase Plant Proteins 2. Zero hunger Multidisciplinary biology digestive oral and skin physiology food and beverages Hordeum 15. Life on land ResearchInstitutes_Networks_Beacons/manchester_institute_of_biotechnology Arabinose 030104 developmental biology chemistry Seedlings Imino Furanoses biology.protein Biophysics Imbibition Xylans 010606 plant biology & botany |
| Zdroj: | Scientific Reports Andriotis, V M E, Rejzek, M, Barclay, E, Rugen, M D, Field, R A & Smith, A M 2016, ' Cell wall degradation is required for normal starch mobilisation in barley endosperm ', Scientific Reports . https://doi.org/10.1038/srep33215 |
| ISSN: | 2045-2322 |
| Popis: | Starch degradation in barley endosperm provides carbon for early seedling growth, but the control of this process is poorly understood. We investigated whether endosperm cell wall degradation is an important determinant of the rate of starch degradation. We identified iminosugar inhibitors of enzymes that degrade the cell wall component arabinoxylan. The iminosugar 1,4-dideoxy-1, 4-imino-l-arabinitol (LAB) inhibits arabinoxylan arabinofuranohydrolase (AXAH) but does not inhibit the main starch-degrading enzymes α- and β-amylase and limit dextrinase. AXAH activity in the endosperm appears soon after the onset of germination and resides in dimers putatively containing two isoforms, AXAH1 and AXAH2. Upon grain imbibition, mobilisation of arabinoxylan and starch spreads across the endosperm from the aleurone towards the crease. The front of arabinoxylan degradation precedes that of starch degradation. Incubation of grains with LAB decreases the rate of loss of both arabinoxylan and starch, and retards the spread of both degradation processes across the endosperm. We propose that starch degradation in the endosperm is dependent on cell wall degradation, which permeabilises the walls and thus permits rapid diffusion of amylolytic enzymes. AXAH may be of particular importance in this respect. These results provide new insights into the mobilization of endosperm reserves to support early seedling growth. |
| Databáze: | OpenAIRE |
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