title: Isoprene emission aids recovery of photosynthetic performance in transgenic Nicotiana tabacum following high intensity acute UV-B exposure.
abstract: Isoprene emission by terrestrial plants is believed to play a role in mitigating the effects of abiotic stress on photosynthesis. Ultraviolet-B light (UV-B) induces damage to the photosynthetic apparatus of plants, but the role of isoprene in UV-B tolerance is poorly understood. To investigate this putative protective role, we exposed non-emitting (NE) control and transgenic isoprene emitting (IE) Nicotiana tabacum (tobacco) plants to high intensity UV-B exposure. Methanol emissions increased with UV-B intensity, indicating oxidative damage. However, isoprene emission was unaffected during exposure to UV-B radiation, but declined in the 48 h following UV-B treatment at the highest UV-B intensities of 9 and 15 Wm(-2). Photosynthesis and the performance of photosystem II (PSII) declined to similar extents in IE and NE plants following UV-B exposure, suggesting that isoprene emission did not ameliorate the immediate impact of UV-B on photosynthesis. However, after the stress, photosynthesis and PSII recovered in IE plants, which maintained isoprene formation, but not in NE plants. Recovery of IE plants was also associated with elevated antioxidant levels and cycling; suggesting that both isoprene formation and antioxidant systems contributed to reinstating the integrity and functionality of cellular membranes and photosynthesis following exposure to excessive levels of UV-B radiation.
authors.affiliation: Trees and Timber Institute, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino, FI, Italy. Electronic address: mauro.centritto@cnr.it.
authors.forename: Mauro
authors.initials: M
authors.lastname: Centritto
authors.affiliation: Institute of Plant Protection, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino, FI, Italy.
authors.forename: Matthew
authors.initials: M
authors.lastname: Haworth
authors.affiliation: Institute of Plant Protection, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino, FI, Italy; Department of Biosciences and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche, IS, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Marino
authors.affiliation: Institute of AgroEnvironmental and Forest Biology, National Research Council, Via Salaria km 29.300, 00015 Monterotondo Scalo, RM, Italy; Department of Forest Environment and Resources, University of Tuscia, Via San Camillo de Lellis, 01100 Viterbo, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Pallozzi
authors.affiliation: Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria.
authors.forename: Tsonko
authors.initials: T
authors.lastname: Tsonev
authors.affiliation: Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria.
authors.forename: Violeta
authors.initials: V
authors.lastname: Velikova
authors.affiliation: Institute of AgroEnvironmental and Forest Biology, National Research Council, Via Salaria km 29.300, 00015 Monterotondo Scalo, RM, Italy.
authors.forename: Isabel
authors.initials: I
authors.lastname: Nogues
authors.affiliation: Institute of Plant Protection, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino, FI, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Loreto
mesh_terms: D002070:Butadienes; D045782:Hemiterpenes / Q000378:metabolism*; D010420:Pentanes; D010788:Photosynthesis; D030821:Plants, Genetically Modified / Q000502:physiology / Q000528:radiation effects; D014026:Nicotiana / Q000502:physiology* / Q000528:radiation effects*; D014466:Ultraviolet Rays; D055549:Volatile Organic Compounds
chemical_list: D002070:Butadienes; D045782:Hemiterpenes; D010420:Pentanes; D055549:Volatile Organic Compounds; C005059:isoprene
keywords: Antioxidant defense; Fluorescence; Isoprene; Methanol; Photosynthesis; UV-B irradiance