TY  - JOUR
A1  - Nuhkat, Maris
A1  - Brosché, Mikael
A1  - Stoezle-Feix, Sonja
A1  - Dietrich, Petra
A1  - Hedrich, Rainer
A1  - Roelfsema, M. Rob G.
A1  - Kollist, Hannes
T1  - Rapid depolarization and cytosolic calcium increase go hand-in-hand in mesophyll cells' ozone response
T2  - New Phytologist
N2  - Plant stress signalling involves bursts of reactive oxygen species (ROS), which can be mimicked by the application of acute pulses of ozone. Such ozone-pulses inhibit photosynthesis and trigger stomatal closure in a few minutes, but the signalling that underlies these responses remains largely unknown.
We measured changes in Arabidopsis thaliana gas exchange after treatment with acute pulses of ozone and set up a system for simultaneous measurement of membrane potential and cytosolic calcium with the fluorescent reporter R-GECO1.
We show that within 1 min, prior to stomatal closure, O\(_{3}\) triggered a drop in whole-plant CO\(_{2}\) uptake. Within this early phase, O\(_{3}\) pulses (200–1000 ppb) elicited simultaneous membrane depolarization and cytosolic calcium increase, whereas these pulses had no long-term effect on either stomatal conductance or photosynthesis. In contrast, pulses of 5000 ppb O\(_{3}\) induced cell death, systemic Ca\(^{2+}\) signals and an irreversible drop in stomatal conductance and photosynthetic capacity.
We conclude that mesophyll cells respond to ozone in a few seconds by distinct pattern of plasma membrane depolarizations accompanied by an increase in the cytosolic calcium ion (Ca\(^{2+}\)) level. These responses became systemic only at very high ozone concentrations. Thus, plants have rapid mechanism to sense and discriminate the strength of ozone signals.
KW  - reactive oxygen species (ROS)
KW  - Arabidopsis thaliana
KW  - Ca\(^{2+}\) indicator
KW  - Ca\(^{2+}\) signalling
KW  - membrane depolarization
KW  - mesophyll
KW  - ozone
Y1  - 2021
UR  - https://opus.bibliothek.uni-wuerzburg.de/frontdoor/index/index/docId/25964
UR  - https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-259646
VL  - 232
IS  - 4
ER  -