Figure 1 Corals exposed to sublethal temperature (29°C) for 3
days become more resilient to following acute heat stress (32°C ). A)
Graphical depiction of preconditioning experiment layout. C – control
corals, NPC – non-preconditioned corals, PC – preconditioned corals.
B) Bleaching rate of PC and NPC corals upon acute heat stress expressed
as symbiont to host cell signal ratio based on confocal fluorescence
microscopy. Graph shows that PC corals are more resilient to thermal
stress and bleach with significantly slower pace than NPC corals. NPC
corals are depicted with grey dashed line, PC with black solid line.
Graph shows mean values with standard error bars. Two-way ANOVA
(microscopy_signal ~ time * conditioning, p = 0.000)
was used to test the influence of conditioning to the bleaching rate. *
marks significantly different values in Tukey’s post hoc test ( p ≦
0.001), n = 6. C) PC and NPC coral fragments after 5-day long heat
stress exposure compared to control coral. D) Confocal fluorescence
microscopy image of control (left) and bleached (right) coral. Host
cells (GFP) are depicted in green, algal cells (chlorophyll) in red.
Figure 2