title: Automated analysis of calcium spiking profiles with CaSA software: two case studies from root-microbe symbioses.
abstract: BACKGROUND
  Repeated oscillations in intracellular calcium (Ca2+) concentration, known as Ca2+ spiking signals, have been described in plants for a limited number of cellular responses to biotic or abiotic stimuli and most notably the common symbiotic signaling pathway (CSSP) which mediates the recognition by their plant hosts of two endosymbiotic microbes, arbuscular mycorrhizal (AM) fungi and nitrogen fixing rhizobia. The detailed analysis of the complexity and variability of the Ca2+ spiking patterns which have been revealed in recent studies requires both extensive datasets and sophisticated statistical tools.
  
  
  RESULTS
  As a contribution, we have developed automated Ca2+ spiking analysis (CaSA) software that performs i) automated peak detection, ii) statistical analyses based on the detected peaks, iii) autocorrelation analysis of peak-to-peak intervals to highlight major traits in the spiking pattern.We have evaluated CaSA in two experimental studies. In the first, CaSA highlighted unpredicted differences in the spiking patterns induced in Medicago truncatula root epidermal cells by exudates of the AM fungus Gigaspora margarita as a function of the phosphate concentration in the growth medium of both host and fungus. In the second study we compared the spiking patterns triggered by either AM fungal or rhizobial symbiotic signals. CaSA revealed the existence of different patterns in signal periodicity, which are thought to contribute to the so-called Ca2+ signature.
  
  
  CONCLUSIONS
  We therefore propose CaSA as a useful tool for characterizing oscillatory biological phenomena such as Ca2+ spiking.
authors.forename: Giulia
authors.initials: G
authors.lastname: Russo
authors.forename: Salvatore
authors.initials: S
authors.lastname: Spinella
authors.forename: Eva
authors.initials: E
authors.lastname: Sciacca
authors.forename: Paola
authors.initials: P
authors.lastname: Bonfante
authors.affiliation: Dipartimento di Scienze della Vita e Biologia dei Sistemi, Università di Torino, Viale P,A, Mattioli 25, 10125 Torino, Italy. andrea.genre@unito.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Genre
mesh_terms: D001331:Automation; D020013:Calcium Signaling / Q000187:drug effects; D003470:Culture Media; D046913:Medicago truncatula / Q000187:drug effects / Q000254:growth & development / Q000382:microbiology*; D038821:Mycorrhizae / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D010710:Phosphates / Q000494:pharmacology; D012231:Rhizobium / Q000502:physiology*; D012984:Software; D013559:Symbiosis / Q000187:drug effects / Q000502:physiology*
chemical_list: D003470:Culture Media; D010710:Phosphates