Role of the vacuole in nutrient balance
Role of the vacuole in nutrient balance
In mature plant cells, up to 90% of the cell volume is occupied by the central vacuole, which represents a storage compartment for proteins, metabolites and many charged nutrients (ions). Most of the ions that are taken up by plants are stored in the vacuole, but under certain conditions these ions also can be released back into the cell sap (cytosol). Despite of importance of vacuoles for plant growth and development, little is known about the mechanisms that regulate the ion transport proteins in vacuolar membrane.
We have developed a method to study the activity of ion channels in the vacuolar membrane of intact cells (Wang et al., 2015, see also Fig.). This method was used to study the role oft he vacuole in the regulation of the calcium homeostasis in root hair cells (Dindas et al., 2021). We found that calcium was taken up into vacuoles by a transport mechanisms that was linked to the difference in acidity between the vacuole and cytosol (pH gradient). This method will be further developed to unravel the molecular mechanisms that are utilized by plants cells to control nutrient storage in the vacuole.
![Fluorescence images of root epidermal cells loaded with the fluorescent dye Lucifer Yellow, either in the cell sap or in the vacuole, and schematic representation of the sub-cellular position of the microelectrode. - Florescent images (left panels in A and B) of root epidermal cells, which were injected with the fluorescent dye „Lucifer Yellow“, via inracellular micro electrodes. The tip oft he electrode was either positioned in the cell sap (cytosol, A) or in the vacuole (B). Schematical representation oft he sub cellular position oft he micro electrode (right panels). Image: R. Roelfsema und Y. Wang, Universität Würzburg Florescent images (left panels in A and B) of root epidermal cells, which were injected with the fluorescent dye „Lucifer Yellow“, via inracellular micro electrodes. The tip oft he electrode was either positioned in the cell sap (cytosol, A) or in the vacuole (B). Schematical representation oft he sub cellular position oft he micro electrode (right panels). Image: R. Roelfsema und Y. Wang, Universität Würzburg](/fileadmin/07010100/refresh_2017/Roelfsema/Abbildungen/Abb-RootVacuole.jpg)