Scientific article
Open access

A genetically validated approach to detect inorganic polyphosphates in plants

Published inPlant Journal, vol. 102, no. 3, p. 507-516
Publication date2019

Inorganic polyphosphates (polyPs) are linear polymers of orthophosphate units linked by phosphoanhydride bonds. PolyPs represent important stores of phosphate and energy, and are abundantly found in many pro- and eukaryotic organisms. In plants, the existence of polyPs has been established using microscopy and biochemical extraction methods that are now known to produce artifacts. Here we use a polyP-specific dye and a polyP binding domain to detect polyPs in plant and algal cells. To develop the staining protocol, we induced polyP granules in Nicotiana benthamiana and Arabiopsis cells by heterologous expression of E. coli polyphosphate kinase 1 (PPK1). Over-expression of PPK1 but not of a catalytically impaired version of the enzyme lead to severe growth phenotypes, suggesting that ATP-dependent synthesis and accumulation of polyPs in the plant cytosol is toxic. We next crossed stable PPK1 expressing Arabidopsis lines with plants expressing the polyP-binding domain of E. coli exopolyphosphatase (PPX1c), which co-localized with PPK1-generated polyP granules. These granules were stained by the polyP-specific dye JC-D7 and appeared as electron dense structures in transmission electron microscopy (TEM) sections. Using the polyP staining protocol derived from these experiments, we screened for polyP stores in different organs and tissues of both mono- and dicotyledonous plants. While we could not detect polyP granules in higher plants, we could visualize the polyP-rich acidocalicisomes in the green algae Chlamydomonas reinhardtii.

Research group
  • Autre - International Research Scholar Award from the Howard Hughes Medical Institute
  • European Commission - Identity and functions of polyphosphate polymerases in eukaryotes [310856]
Citation (ISO format)
ZHU, Jinsheng et al. A genetically validated approach to detect inorganic polyphosphates in plants. In: Plant Journal, 2019, vol. 102, n° 3, p. 507–516. doi: 10.1111/tpj.14642
Main files (2)
Article (Accepted version)
Article (Published version)
ISSN of the journal0960-7412

Technical informations

Creation12/19/2019 1:22:00 PM
First validation12/19/2019 1:22:00 PM
Update time05/17/2023 12:31:19 PM
Status update05/17/2023 12:31:19 PM
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