Waxy and non-waxy barley cultivars exhibit differences in the targeting and catalytic activity of GBSS1a
© The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.
| Veröffentlicht in: | Journal of experimental botany. - 1985. - 68(2017), 5 vom: 01. Feb., Seite 931-941 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2017
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| Zugriff auf das übergeordnete Werk: | Journal of experimental botany |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Amylose GBSS starch biosynthesis starch functionality subcellular targeting waxy. Plant Proteins 9005-82-7 mehr... |
| Zusammenfassung: | © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. Amylose synthesis is strictly associated with activity of granule-bound starch synthase (GBSS) enzymes. Among several crops there are cultivars containing starch types with either little or no amylose known as near-waxy or waxy. This (near) amylose-free phenotype is associated with a single locus (waxy) which has been mapped to GBSS-type genes in different crops. Most waxy varieties are a result of either low or no expression of a GBSS gene. However, there are some waxy cultivars where the GBSS enzymes are expressed normally. For these types, single nucleotide polymorphisms have been hypothesized to represent amino-acid substitutions leading to loss of catalytic activity. We here confirm that the HvGBSSIa enzyme from one such waxy barley variety, CDC_Alamo, has a 90% reduction in catalytic activity. We also engineered plants with expression of transgenic C-terminal green fluorescent protein-tagged HvGBSSIa of both the non-waxy type and of the CDC_Alamo type to monitor their subcellular localization patterns in grain endosperm. HvGBSSIa from non-waxy cultivars was found to localize in discrete concentric spheres strictly within starch granules. In contrast, HvGBSSIa from waxy CDC_Alamo showed deficient starch targeting mostly into unknown subcellular bodies of 0.5-3 µm in size, indicating that the waxy phenotype of CDC_Alamo is associated with deficient targeting of HvGBSSIa into starch granules |
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| Beschreibung: | Date Completed 16.11.2017 Date Revised 13.11.2018 published: Print Citation Status MEDLINE |
| ISSN: | 1460-2431 |
| DOI: | 10.1093/jxb/erw503 |