Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Transgenic aequorin monitors cytosolic calcium transients in soybean cells challenged with β-glucan or chitin elicitors

  • 157 Accesses

  • 84 Citations


Transgenic soybean (Glycine max L.) cells expressing aequorin were used to monitor changes in cytosolic Ca2+ concentrations in response to treatment with fungal elicitors. After an apparent lag phase of about 60 s, both chitin fragments and β-glucan elicitors caused a rapid increase in cytosolic Ca2+ concentration, which peaked within 2–2.5 min of treatment. The Ca2+ concentration then decreased and reached the basal level after about 5 min in the case of the treatment with chitin fragments, while a second rise in the Ca2+ concentration with a maximum occurring after about 7–8 min was observed in the case of β-glucan treatment. Calibration of the signals showed that the elicitors enhanced the cytosolic Ca2+ concentration from resting concentrations as low as 0.1 lM to highest levels of about 2 lM. Dose-response experiments showed that the concentration of elicitors giving a Ca2+ response at the 50% level was 0.4 nM for the chitin fragment and 28 lM and 72 lM, respectively, for a synthetic hepta-β-glucoside and a fungal β-glucan fraction. The β-glucan- or N,N′,N′′,N′′′-tetraacetyl chitotetratose (CH4)-induced Ca2+ signals were inhibited by both the Ca2+ chelator 1,2-bis-(2-aminophenoxy) ethane-N,N,N′,N′-tetraacetic acid (BAPTA) and by the Ca2+-channel inhibitor La3+. Neomycin, whose target in plant cells has not yet been clearly identified, reduced predominantly the expression of the second peak of the biphasic Ca2+ curve following β-glucan treatment. Bacterial cyclic β-glucans known to suppress β-glucan-induced phytoalexin production were also found to function as a suppressor for the Ca2+ response that was elicited by the fungal β-glucans. The results clearly show that the increase in the cytosolic Ca2+ concentration is an early and rapid event in the elicitor-sensing mechanism of soybean cells, and is probably connected with the subsequent activation of defence responses.

This is a preview of subscription content, log in to check access.

Author information

Additional information

Received: 23 July 1998 / Accepted: 16 October 1998

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Mithöfer, A., Ebel, J., Bhagwat, A. et al. Transgenic aequorin monitors cytosolic calcium transients in soybean cells challenged with β-glucan or chitin elicitors. Planta 207, 566–574 (1999). https://doi.org/10.1007/s004250050519

Download citation

  • Key words: Aequorin
  • Cytosolic calcium
  • β-Glucan elicitor
  • Glycine (Ca2+ transients)