1. Isoprene emission protects photosynthesis but reduces plant productivity during drought in transgenic tobacco (Nicotiana tabacum) plants.
- Author
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Ryan AC, Hewitt CN, Possell M, Vickers CE, Purnell A, Mullineaux PM, Davies WJ, and Dodd IC
- Subjects
- Abscisic Acid metabolism, Lipid Peroxidation, Photosystem II Protein Complex metabolism, Plant Growth Regulators metabolism, Plant Leaves metabolism, Plant Leaves physiology, Plants, Genetically Modified, Reactive Oxygen Species metabolism, Nicotiana growth & development, Nicotiana metabolism, Biomass, Butadienes metabolism, Droughts, Hemiterpenes metabolism, Oxidative Stress, Pentanes metabolism, Photosynthesis, Nicotiana physiology, Water physiology
- Abstract
Isoprene protects the photosynthetic apparatus of isoprene-emitting plants from oxidative stress. The role of isoprene in the response of plants to drought is less clear. Water was withheld from transgenic isoprene-emitting and non-emitting tobacco (Nicotiana tabacum) plants, to examine: the response of isoprene emission to plant water deficit; a possible relationship between concentrations of the drought-induced phytohormone abscisic acid (ABA) and isoprene; and whether isoprene affected foliar reactive oxygen species (ROS) and lipid peroxidation levels. Isoprene emission did not affect whole-plant water use, foliar ABA concentration or leaf water potential under water deficit. Compared with well-watered controls, droughted non-emitting plants significantly increased ROS content (31-46%) and lipid peroxidation (30-47%), concomitant with decreased operating and maximum efficiencies of photosystem II photochemistry and lower leaf and whole-plant water use efficiency (WUE). Droughted isoprene-emitting plants showed no increase in ROS content or lipid peroxidation relative to well-watered controls, despite isoprene emission decreasing before leaf wilting. Although isoprene emission protected the photosynthetic apparatus and enhanced leaf and whole-plant WUE, non-emitting plants had 8-24% more biomass under drought, implying that isoprene emission incurred a yield penalty., (© 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.)
- Published
- 2014
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