| 1. |
- Betts, Natalie S., et al.
(författare)
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Identification and spatio-temporal expression analysis of barley genes that encode putative modular xylanolytic enzymes
- 2021
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Ingår i: Plant Science. - : Elsevier BV. - 0168-9452 .- 1873-2259. ; 308
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Tidskriftsartikel (refereegranskat)abstract
- Arabinoxylans are cell wall polysaccharides whose re-modelling and degradation during plant development are mediated by several classes of xylanolytic enzymes. Here, we present the identification and new annotation of twelve putative (1,4)-13-xylanase and six 13-xylosidase genes, and their spatio-temporal expression patterns during vegetative and reproductive growth of barley (Hordeum vulgare cv. Navigator). The encoded xylanase proteins are all predicted to contain a conserved carbohydrate-binding module (CBM) and a catalytic glycoside hydrolase (GH) 10 domain. Additional domains in some xylanases define three discrete phylogenetic clades: one clade contains proteins with an additional N-terminal signal sequence, while another clade contains proteins with multiple CBMs. Homology modelling revealed that all fifteen xylanases likely contain a third domain, a 13-sandwich folded from two non-contiguous sequence segments that bracket the catalytic GH domain, which may explain why the full length protein is required for correct folding of the active enzyme. Similarly, predicted xylosidase proteins share a highly conserved domain structure, each with an N-terminal signal peptide, a split GH 3 domain, and a C-terminal fibronectin-like domain. Several genes appear to be ubiquitously expressed during barley growth and development, while four newly annotated xylanase and xylosidase genes are expressed at extremely high levels, which may be of broader interest for industrial applications where cell wall degradation is necessary.
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| 2. |
- Dymek, Katarzyna, et al.
(författare)
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Effect of pulsed electric field on the germination of barley seeds
- 2012
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Ingår i: LWT - Food Science and Technology. - : Elsevier BV. - 0023-6438. ; 47:1, s. 161-166
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Tidskriftsartikel (refereegranskat)abstract
- This study explores metabolic responses of germinating barley seeds upon the application of pulsed electric fields (PEE). Malting barley seeds were steeped in aerated water for 24 h and PEF-treated at varying voltages (0 (control), 110, 160, 240, 320, 400 and 480 V). The seeds were then allowed to finish germination in saturated air. It is shown that exposure of germinating barley to PEE affects radicle emergence without significantly affecting the seeds gross metabolic activity, as quantified by isothermal calorimetry. An exploration of protein 2-DE profiles of both the embryo and the starchy endosperm showed that, at the studied time scale, no significant changes were found in proteins present at concentrations higher than the detection limit. However, western blotting demonstrated that a-amylase concentration decreases in the PEF-treated seeds. (C) 2011 Elsevier Ltd. All rights reserved.
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