Cell Type-Specific Imaging of Calcium Signaling in Arabidopsis thaliana Seedling Roots Using GCaMP3

Int J Mol Sci. 2020 Sep 2;21(17):6385. doi: 10.3390/ijms21176385.


Cytoplasmic calcium ([Ca2+]cyt) is a well-characterized second messenger in eukaryotic cells. An elevation in [Ca2+]cyt levels is one of the earliest responses in plant cells after exposure to a range of environmental stimuli. Advances in understanding the role of [Ca2+]cyt in plant development has been facilitated by the use of genetically-encoded reporters such as GCaMP. Most of these studies have relied on promoters such as Cauliflower Mosaic Virus (35S) and Ubiquitin10 (UBQ10) to drive expression of GCaMP in all cell/tissue types. Plant organs such as roots consist of various cell types that likely exhibit unique [Ca2+]cyt responses to exogenous and endogenous signals. However, few studies have addressed this question. Here, we introduce a set of Arabidopsis thaliana lines expressing GCaMP3 in five root cell types including the columella, endodermis, cortex, epidermis, and trichoblasts. We found similarities and differences in the [Ca2+]cyt signature among these root cell types when exposed to adenosine tri-phosphate (ATP), glutamate, aluminum, and salt, which are known to trigger [Ca2+]cyt increases in root cells. These cell type-targeted GCaMP3 lines provide a new resource that should enable more in depth studies that address how a particular environmental stimulus is linked to specific root developmental pathways via [Ca2+]cyt.

Keywords: Arabidopsis; GCaMP3; [Ca2+]cyt; calcium response; cell type specificity.

MeSH terms

  • Arabidopsis / growth & development
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / metabolism*
  • Calcium / metabolism*
  • Calcium Signaling*
  • Luminescent Proteins / metabolism*
  • Molecular Imaging
  • Plant Roots / classification
  • Plant Roots / growth & development
  • Plant Roots / metabolism*
  • Seedlings / metabolism*


  • Arabidopsis Proteins
  • Luminescent Proteins
  • Calcium