Despite
that single-cell-type-level analyses have been extensively
conducted on animal models to gain new insights into complex biological
processes; the unique biological and physiological properties of plant
cells have not been widely studied at single-cell resolution. In this
work, an electrical impedance flow cytometry was fabricated based
on microfluidics with constriction microchannel to simultaneously
characterize the mechanical and electrical properties of single plant
cells. Protoplasts from two model plant species, the herbaceous Arabidopsis thaliana and the woody Populus trichocarpa, could be readily discriminated
by their respective mechanical traits, but not by electrical impedance.
On the contrary, overexpression of a red fluorescent protein on plasma
membrane resulted in changes in cell electrical impedance instead
of cell deformability. During primary cell wall (PCW) regeneration,
this extracellular layer outside of protoplasts introduced dramatic
variations in both mechanical and electrical properties of single
plant cells. Furthermore, the effects of auxin, an essential phytohormone
regulating PCW reformation, were validated on this platform. Taken
together, our results revealed a novel application of microfluidic
impedance flow cytometry in the field of plant science to simultaneously
characterize dual biophysical properties at single-cell resolution,
which could be further developed as a powerful and reliable tool for
plant cell phenotyping and cell fate specification.