RT Journal Article
SR Electronic
T1 Contrasting avoidance - tolerance in heat stress response from thermally contrasting climates in Arabidopsis thaliana
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 044461
DO 10.1101/044461
A1 Nana Zhang
A1 Philip Carlucci
A1 Joshua Nguyen
A1 Jai-W Hayes-Jackson
A1 Stephen Tonsor
YR 2016
UL http://biorxiv.org/content/early/2016/03/18/044461.abstract
AB Plants ameliorate heat stress by avoiding heat loading, reducing tissue temperature through evaporative cooling, and/or through tolerance, i.e. maintaining function at high temperature. Here Arabidopsis thaliana natural populations from two ends of an elevation gradient in NE Spain were used to ask: do plants from contrasting climates 1) show genetically based differences in heat stress damage and 2) adopt different avoidance-tolerance patterns? Four low-and four high-elevation populations were repeatedly exposed to high temperature (45°C) in a growth chamber at bolting stage. High temperature induced 23% more inflorescence branches, 25% longer total reproductive branch length, and 12% less root dry mass, compared with control. However summed fruit length, hence fitness, decreased by 15%, populations did not differ significantly in fitness reduction. High elevation populations showed more avoidance, i.e. lower rosette temperature at 45°C. Low elevation populations showed more tolerance, maintaining relatively higher photosynthetic rate at 45°C. Avoidance was associated with high transpiration rate and flat rosette leaf angle. Tolerance was negatively associated with heat shock protein 101 (Hsp101) and salicylic acid (SA) accumulation. The divergent avoidance–tolerance patterns for populations from thermally contrasting climates may indicate both constraints on the evolution and contrasting adaptive divergence regulated by local climates.