Towards the Physics of Calcium Signalling in Plants

Abstract

Calcium is an abundant element with a wide variety of important roles within cells. Calcium ions are inter- and intra-cellular messengers that are involved in numerous signalling pathways. Fluctuating compartment-specific calcium ion concentrations can lead to localised and even plant-wide oscillations that can regulate downstream events. Understanding the mechanisms that give rise to these complex patterns that vary both in space and time can be challenging, even in cases for which individual components have been identified. Taking a systems biology approach, mathematical and computational techniques can be employed to produce models that recapitulate experimental observations and capture our current understanding of the system. Useful models make novel predictions that can be investigated and falsified experimentally. This review brings together recent work on the modelling of calcium signalling in plants, from the scale of ion channels through to plant-wide responses to external stimuli. Some in silico results that have informed later experiments are highlighted.

The Ca2+-Regulation of the Mitochondrial External NADPH Dehydrogenase in Plants Is Controlled by Cytosolic pH

“…In plant cells, the concentration of free Ca 2+ in the cytosol is strongly fluctuating, displaying upward transient spikes over a low “resting” concentration around 100 nM [ 40 ]. External NADH oxidation in H .…”

Advances and current challenges in calcium signaling

“…A few groups have set up rather generic models of Ca 2+ signaling (no biochemical details) in order to understand, for example, signal spread and the impact of physical properties like temperature. A vertebrate model by Li and Rinzel has been adapted to plant conditions to study Ca 2+ signaling in Nicotiana tabacum cell culture (Martins et al, 2013;Mrozek et al, 2013). In addition, also using a simplified core model for Ca 2+ signaling, first studies on encoding and decoding have been performed (Bose et al, 2011).…”

Cellular Ca2+ Signals Generate Defined pH Signatures in Plants

“…The energy required to maintain such a large electrochemical Ca 2+ gradient is provided by ATP, which is used directly by Ca 2+ -ATPases and indirectly by Ca 2+ antiporters, such as Ca 2+ /H + exchangers (e.g., CAX proteins), to extrude Ca 2+ out of the cytosol driven by the proton motive force (Bonza and De Michelis, 2011;Emery et al, 2012;Martins et al, 2013). Using H + gradients generated by P-type and V-type ATPases at both the PM and tonoplast (Serrano, 1989;Gaxiola et al, 2007;Duby and Boutry, 2009), Ca 2+ /H + transporters link the transport of Ca 2+ with the transport of H + .…”