KUP 9 maintains root meristem activity by regulating K + and auxin homeostasis in response to low K
Autor: | Yun Ji, Yi Wang, Pan-Pan Huang, Mei-Ling Zhang, Wei-Hua Wu, Shao-Shuai Wang, Shuwei Wang, Zhen Li, Yan Guo, Zhaojun Ding |
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Rok vydání: | 2020 |
Předmět: |
chemistry.chemical_classification
Auxin efflux 0303 health sciences biology Auxin homeostasis Cell division Endoplasmic reticulum fungi food and beverages Meristem biology.organism_classification Biochemistry Cell biology 03 medical and health sciences 0302 clinical medicine chemistry Auxin Cytoplasm Arabidopsis Genetics Molecular Biology 030217 neurology & neurosurgery 030304 developmental biology |
Zdroj: | EMBO reports. 21 |
ISSN: | 1469-3178 1469-221X |
Popis: | Potassium (K) is essential for plant growth and development. Here, we show that the KUP/HAK/KT K+ transporter KUP9 controls primary root growth in Arabidopsis thaliana. Under low-K+ conditions, kup9 mutants displayed a short-root phenotype that resulted from reduced numbers of root cells. KUP9 was highly expressed in roots and specifically expressed in quiescent center (QC) cells in root tips. The QC acts to maintain root meristem activity, and low-K+ conditions induced QC cell division in kup9 mutants, resulting in impaired root meristem activity. The short-root phenotype and enhanced QC cell division in kup9 mutants could be rescued by exogenous auxin treatment or by specifically increasing auxin levels in QC cells, suggesting that KUP9 affects auxin homeostasis in QC cells. Further studies showed that KUP9 mainly localized to the endoplasmic reticulum (ER), where it mediated K+ and auxin efflux from the ER lumen to the cytoplasm in QC cells under low-K+ conditions. These results demonstrate that KUP9 maintains Arabidopsis root meristem activity and root growth by regulating K+ and auxin homeostasis in response to low-K+ stress. |
Databáze: | OpenAIRE |
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