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DOI

  • Tyeen C. Taylor
    University of Arizona, Tucson
  • Marielle Smith
    Michigan State University
  • Martijn Slot
    Smithsonian Tropical Research Institute
  • Kenneth J. Feeley
    University of Miami
Experimental research shows that isoprene emission by plants can improve photosynthetic performance at high temperatures. But whether species that emit isoprene have higher thermal limits than non-emitting species remains largely untested. Tropical plants are adapted to narrow temperature ranges and global warming could result in significant ecosystem restructuring due to small variations in species' thermal tolerances. We compared photosynthetic temperature responses of 26 co-occurring tropical tree and liana species to test whether isoprene-emitting species are more tolerant to high temperatures. We classified species as isoprene emitters versus non-emitters based on published datasets. Maximum temperatures for net photosynthesis were ~1.8°C higher for isoprene-emitting species than for non-emitters, and thermal response curves were 24% wider; differences in optimum temperatures (Topt) or photosynthetic rates at Topt were not significant. Modelling the carbon cost of isoprene emission, we show that even strong emission rates cause little reduction in the net carbon assimilation advantage over non-emitters at supraoptimal temperatures. Isoprene emissions may alleviate biochemical limitations, which together with stomatal conductance, co-limit photosynthesis above Topt. Our findings provide evidence that isoprene emission may be an adaptation to warmer thermal niches, and that emitting species may fare better under global warming than co-occurring non-emitting species.
Original languageEnglish
Pages (from-to)2448-2457
JournalPlant Cell and Environment
Volume42
Issue number8
Early online date16 Apr 2019
DOIs
Publication statusPublished - 1 Aug 2019
Externally publishedYes
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