Lipid kinases PIP5K7 and PIP5K9 are required for polyamine-triggered K+ efflux in Arabidopsis roots.
Plant J
; 104(2): 416-432, 2020 10.
Article
en En
| MEDLINE
| ID: mdl-32666545
ABSTRACT
Polyamines, such as putrescine, spermidine and spermine (Spm), are low-molecular-weight polycationic molecules present in all living organisms. Despite their implication in plant cellular processes, little is known about their molecular mode of action. Here, we demonstrate that polyamines trigger a rapid increase in the regulatory membrane lipid phosphatidylinositol 4,5-bisphosphate (PIP2 ), and that this increase is required for polyamine effects on K+ efflux in Arabidopsis roots. Using in vivo 32 Pi -labelling of Arabidopsis seedlings, low physiological (µm) concentrations of Spm were found to promote a rapid PIP2 increase in roots that was time- and dose-dependent. Confocal imaging of a genetically encoded PIP2 biosensor revealed that this increase was triggered at the plasma membrane. Differential 32 Pi -labelling suggested that the increase in PIP2 was generated through activation of phosphatidylinositol 4-phosphate 5-kinase (PIP5K) activity rather than inhibition of a phospholipase C or PIP2 5-phosphatase activity. Systematic analysis of transfer DNA insertion mutants identified PIP5K7 and PIP5K9 as the main candidates involved in the Spm-induced PIP2 response. Using non-invasive microelectrode ion flux estimation, we discovered that the Spm-triggered K+ efflux response was strongly reduced in pip5k7 pip5k9 seedlings. Together, our results provide biochemical and genetic evidence for a physiological role of PIP2 in polyamine-mediated signalling controlling K+ flux in plants.
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1
Banco de datos:
MEDLINE
Asunto principal:
Potasio
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Arabidopsis
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Fosfotransferasas (Aceptor de Grupo Alcohol)
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Raíces de Plantas
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Proteínas de Arabidopsis
Idioma:
En
Revista:
Plant J
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BOTANICA
Año:
2020
Tipo del documento:
Article
País de afiliación:
Países Bajos