DIACYLGLYCEROL KINASE 5 regulates polar tip growth of tobacco pollen tubes
© 2021 The Authors. New Phytologist © 2021 New Phytologist Foundation.
| Publié dans: | The New phytologist. - 1979. - 233(2022), 5 vom: 20. März, Seite 2185-2202 |
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| Auteur principal: | |
| Autres auteurs: | , , , , , , , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2022
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| Accès à la collection: | The New phytologist |
| Sujets: | Journal Article Research Support, Non-U.S. Gov't diacylglycerol kinase lipid signaling pectin phosphatidic acid pollen tube secretion tobacco (Nicotiana tabacum) Phosphatidylinositols plus... |
| Résumé: | © 2021 The Authors. New Phytologist © 2021 New Phytologist Foundation. Pollen tubes require a tightly regulated pectin secretion machinery to sustain the cell wall plasticity required for polar tip growth. Involved in this regulation at the apical plasma membrane are proteins and signaling molecules, including phosphoinositides and phosphatidic acid (PA). However, the contribution of diacylglycerol kinases (DGKs) is not clear. We transiently expressed tobacco DGKs in pollen tubes to identify a plasma membrane (PM)-localized isoform, and then to study its effect on pollen tube growth, pectin secretion and lipid signaling. In order to potentially downregulate DGK5 function, we overexpressed an inactive variant. Only one of eight DGKs displayed a confined localization at the apical PM. We could demonstrate its enzymatic activity and that a kinase-dead variant was inactive. Overexpression of either variant led to differential perturbations including misregulation of pectin secretion. One mode of regulation could be that DGK5-formed PA regulates phosphatidylinositol 4-phosphate 5-kinases, as overexpression of the inactive DGK5 variant not only led to a reduction of PA but also of phosphatidylinositol 4,5-bisphosphate levels and suppressed related growth phenotypes. We conclude that DGK5 is an additional player of polar tip growth that regulates pectin secretion probably in a common pathway with PI4P 5-kinases |
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| Description: | Date Completed 24.03.2022 Date Revised 13.12.2023 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.17930 |