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Regulation of isoprene emission in Populus trichocarpa leaves subjected to changing growth temperature
Author(s) -
WIBERLEY AMY E.,
DONOHUE AUTUMN R.,
MEIER MARY E.,
WESTPHAL MAIKEN M.,
SHARKEY THOMAS D.
Publication year - 2008
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/j.1365-3040.2007.01758.x
Subject(s) - isoprene , populus trichocarpa , salicaceae , botany , horticulture , chemistry , biology , woody plant , biochemistry , genome , gene , organic chemistry , copolymer , polymer
The hydrocarbon isoprene is emitted in large quantities from numerous plant species, and has a substantial impact on atmospheric chemistry. Temperature affects isoprene emission at several levels: the temperature at which emission is measured, the temperature at which leaves develop, and the temperatures to which a mature leaf is exposed in the days prior to emission measurement. The molecular regulation of the response to the last of these factors was investigated in this study. When plants were grown at 20 °C and moved from 20 to 30 °C and back, or grown at 30 °C and moved from 30 to 20 °C and back, their isoprene emission peaked within 3 h of the move and stabilized over the following 3 d. Trees that developed at 20 °C and experienced 30 °C episodes had higher isoprene emission capacities than did leaves grown exclusively at 20 °C, even 2 weeks after the last 30 °C episode. The levels and extractable activities of isoprene synthase protein, which catalyses the synthesis of isoprene, and those of dimethylallyl diphosphate (DMADP), its substrate, alone could not explain observed variations in isoprene emission. Therefore, we conclude that control of isoprene emission in mature leaves is shared between isoprene synthase protein and DMADP supply.