Stress‐induced changes in carbon sources for isoprene production in Populus deltoides

• Published in: Plant, cell and environment cell and environment, 2004-06, Vol.27 (6), p.747-755
• Main Authors: FUNK, J. L., MAK, J. E., LERDAU, M. T.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Metabolism; Photosynthesis, respiration. Anabolism, catabolism; plant hydrocarbon emission; Plant physiology and development; stable carbon isotopes; substrate regulation; temperature; water stress
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/j.1365-3040.2004.01177.x

ABSTRACT Isoprene is emitted from leaves of numerous plant species and has important implications for plant metabolism and atmospheric chemistry. The ability to use stored carbon (alternative carbon sources), as opposed to recently assimilated photosynthate, for isoprene production may be important as plants routinely experience photosynthetic depression in response to environmental stress. A CO2‐labelling study was performed and stable isotopes of carbon were used to examine the role of alternative carbon sources in isoprene production in Populus deltoides during conditions of water stress and high leaf temperature. Isotopic fractionation during isoprene production was higher in heat‐ and water‐stressed leaves (−8.5 and −9.3‰, respectively) than in unstressed controls (−2.5 to −3.2‰). In unstressed plants, 84–88% of the carbon in isoprene was derived from recently assimilated photosynthate. A significant shift in the isoprene carbon composition from photosynthate to alternative carbon sources was observed only under severe photosynthetic limitation (stomatal conductance