The role of calcium in chloroplasts—an intriguing and unresolved puzzle

Exogenous Calcium Alleviates Low Night Temperature Stress on the Photosynthetic Apparatus of Tomato Leaves

“…However, CEF contributes to the pH gradient across the thylakoid membrane, which is required for efficient qE. Application of Ca 2+ may also increase the binding of CaM to NADK2, which is known to modulate the NAD/NADP balance [36], [61]. Furthermore, our study also showed that ATPase activity was promoted by exogenous calcium under LNT (Fig.…”

“…5). Previous studies have shown that the calcium-binding protein CAS is crucial for maintaining PSII activity, recovery, and/or turnover, as well as in driving high light acclimation [36], [61]. In the present study, exogenous calcium only slightly decreased Y (NO), whereas EGTA pretreatment significantly increased it under LNT (Fig.…”

Chloroplast calcium and ROS signaling networks potentially facilitate the primed state for stomatal closure under multiple stresses

“…Interestingly, Ca 2+ str transients, in turn, inhibit the catalytic activity of key enzymes in the CO 2 fixation process (Muhlenbock et al, 2008;Rocha and Vothknecht, 2012), leading to the further production of ROS by the over-reduction of the PQ pool under light conditions (Asada, 1999;Liu et al, 2007;Schmitt et al, 2014). This result is also supported by our previous studies showing Ca 2 + -induced H 2 O 2 generation from extracted chloroplasts in vitro (Wang et al, 2012).…”

Chloroplast-Specific in Vivo Ca2+ Imaging Using Yellow Cameleon Fluorescent Protein Sensors Reveals Organelle-Autonomous Ca2+ Signatures in the Stroma

“…Despite quantitative estimation and measurement of relative changes in free Ca 2+ concentrations in different chloroplast subcompartments using aequorin Sello et al, 2016), the extent and direction of intraplastidial Ca 2+ fluxes or Ca 2+ transport into and from the cytosol are currently not understood and none of the transporters involved has been identified (Rocha and Vothknecht, 2012;Finazzi et al, 2015). Accordingly, it remains unknown how stromal Ca 2+ dynamics and signaling are orchestrated.…”