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A model of plant isoprene emission based on available reducing power captures responses to atmospheric CO 2
Author(s) -
Morfopoulos Catherine,
Sperlich Dominik,
Peñuelas Josep,
Filella Iolanda,
Llusià Joan,
Medlyn Belinda E.,
Niinemets Ülo,
Possell Malcolm,
Sun Zhihong,
Prentice Iain Colin
Publication year - 2014
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.12770
Subject(s) - isoprene , photosynthesis , atmospheric sciences , carbon fixation , environmental science , ecosystem , chemistry , botany , ecology , physics , biology , organic chemistry , copolymer , polymer
Summary We present a unifying model for isoprene emission by photosynthesizing leaves based on the hypothesis that isoprene biosynthesis depends on a balance between the supply of photosynthetic reducing power and the demands of carbon fixation. We compared the predictions from our model, as well as from two other widely used models, with measurements of isoprene emission from leaves of P opulus nigra and hybrid aspen ( P opulus tremula × P . tremuloides ) in response to changes in leaf internal CO 2 concentration ( C i ) and photosynthetic photon flux density ( PPFD ) under diverse ambient CO 2 concentrations ( C a ). Our model reproduces the observed changes in isoprene emissions with C i and PPFD , and also reproduces the tendency for the fraction of fixed carbon allocated to isoprene to increase with increasing PPFD . It also provides a simple mechanism for the previously unexplained decrease in the quantum efficiency of isoprene emission with increasing C a . Experimental and modelled results support our hypothesis. Our model can reproduce the key features of the observations and has the potential to improve process‐based modelling of isoprene emissions by land vegetation at the ecosystem and global scales.