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Plasticity of photosynthetic heat tolerance in plants adapted to thermally contrasting biomes
Author(s) -
Zhu Lingling,
Bloomfield Keith J.,
Hocart Charles H.,
Egerton John J.G.,
O'Sullivan Odhran S.,
Penillard Aurore,
Weerasinghe Lasantha K.,
Atkin Owen K.
Publication year - 2018
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.13133
Subject(s) - biome , acclimatization , photosynthesis , biology , habitat , ecology , photosystem ii , seasonality , phenotypic plasticity , botany , ecosystem
In many biomes, plants are subject to heatwaves, potentially causing irreversible damage to the photosynthetic apparatus. Field surveys have documented global, temperature‐dependent patterns in photosynthetic heat tolerance ( P HT ); however, it remains unclear if these patterns reflect acclimation in P HT or inherent differences among species adapted to contrasting habitats. To address these unknowns, we quantified seasonal variations in T crit (high temperature where minimal chlorophyll‐ a fluorescence rises rapidly, reflecting disruption to photosystem II) in 62 species native to 6 sites from 5 thermally contrasting biomes across Australia. T crit and leaf fatty acid (FA) composition (important for membrane stability) were quantified in three temperature‐controlled glasshouses in 20 of those species. T crit was greatest at hot field sites and acclimated seasonally (summer > winter, increasing on average 0.34 °C per °C increase in growth temperature). The glasshouse study showed that T crit was inherently higher in species from warmer habitats (increasing 0.16 °C per °C increase in origin annual mean maximum temperature) and acclimated to increasing growth temperature (0.24 °C °C −1 ). Variations in T crit were positively correlated with the relative abundance of saturated FAs, with FAs accounting for 40% of T crit variation. These results highlight the importance of both plastic adjustments and inherent differences determining contemporary continent‐wide patterns in P HT .