Genetic structure and regulation of isoprene synthase in Poplar (Populus spp.)
- 473 Downloads
Isoprene is a volatile 5-carbon hydrocarbon derived from the chloroplastic methylerythritol 2-C-methyl-d-erythritol 4-phosphate isoprenoid pathway. In plants, isoprene emission is controlled by the enzyme isoprene synthase; however, there is still relatively little known about the genetics and regulation of this enzyme. Isoprene synthase gene structure was analysed in three poplar species. It was found that genes encoding stromal isoprene synthase exist as a small gene family, the members of which encode virtually identical proteins and are differentially regulated. Accumulation of isoprene synthase protein is developmentally regulated, but does not differ between sun and shade leaves and does not increase when heat stress is applied. Our data suggest that, in mature leaves, isoprene emission rates are primarily determined by substrate (dimethylallyl diphosphate, DMADP) availability. In immature leaves, where isoprene synthase levels are variable, emission levels are also influenced by the amount of isoprene synthase protein. No thylakoid isoforms could be identified in Populus alba or in Salix babylonica. Together, these data show that control of isoprene emission at the genetic level is far more complicated than previously assumed.
KeywordsIsoprene Poplar Isoprene synthase Developmental regulation Isoprenoid pathway
This research was funded by the UK Biotechnology and Biological Sciences Research Council (BBSRC) grant number BBS/B/12172. The full-length anti-isoprene synthase antibody was kindly provided by Dr Jörg-Peter Schnitzler, IMK-IFU, Garmisch, Germany. We thank Dr Oksana Zakhleniuk and Mr Daniel Exton for skilled technical assistance.
- Brilli F, Barta C, Fortunati A, Centritto M, Loreto F (2006) The contribution of different carbon sources to isoprene synthesis during and after drought in Populus alba leaves. Geophys Res Abs 8:EGU06-A-04113Google Scholar
- Cinege G, Louis S, Hänsch R, Schnitzler JP (2008) Regulation of isoprene synthase promoter by environmental and internal factors. Plant Mol BiolGoogle Scholar
- Loivamäki M, Louis S, Cinege G, Zimmer I, Fischbach RJ, Schnitzler JP (2006) Circadian rhythms of isoprene biosynthesis in Grey Poplar leaves. Plant Physiol 106Google Scholar
- Rajora OP, Dancik BP (1992) Genetic characterization and relationships of Populus alba, P. tremula, and P. × canescens, and their clones. Theor Appl Genet V84:291–298Google Scholar
- Rasulov B, Copolovici L, Laisk A, Niinemets U (2009) Postillumination isoprene emission: in vivo measurements of dimethylallyldiphosphate pool size and isoprene synthase kinetics in aspen leaves. Plant Physiol 108Google Scholar
- Sambrook J, Fritsch EF Maniatis, Maniatis T (1989) Molecular Cloning: a laboratory manual. Cold Spring Harbour Laboratory Press, New YorkGoogle Scholar
- Schnitzler JP, Zimmer I, Bachl A, Arend M, Fromm J, Fischbach RJ (2005) Biochemical properties of isoprene synthase in poplar (Populus × canescens). Planta 1-10Google Scholar
- Tuskan GA, DiFazio S, Jansson S, Bohlmann J, Grigoriev I, Hellsten U, Putnam N, Ralph S, Rombauts S, Salamov A, Schein J, Sterck L, Aerts A, Bhalerao RR, Bhalerao RP, Blaudez D, Boerjan W, Brun A, Brunner A, Busov V, Campbell M, Carlson J, Chalot M, Chapman J, Chen GL, Cooper D, Coutinho PM, Couturier J, Covert S, Cronk Q, Cunningham R, Davis J, Degroeve S, Dejardin A, dePamphilis C, Detter J, Dirks B, Dubchak I, Duplessis S, Ehlting J, Ellis B, Gendler K, Goodstein D, Gribskov M, Grimwood J, Groover A, Gunter L, Hamberger B, Heinze B, Helariutta Y, Henrissat B, Holligan D, Holt R, Huang W, Islam-Faridi N, Jones S, Jones-Rhoades M, Jorgensen R, Joshi C, Kangasjarvi J, Karlsson J, Kelleher C, Kirkpatrick R, Kirst M, Kohler A, Kalluri U, Larimer F, Leebens-Mack J, Leple JC, Locascio P, Lou Y, Lucas S, Martin F, Montanini B, Napoli C, Nelson, Nelson C, Nieminen K, Nilsson O, Pereda V, Peter G, Philippe R, Pilate G, Poliakov A, Razumovskaya J, Richardson P, Rinaldi C, Ritland K, Rouze P, Ryaboy D, Schmutz J, Schrader J, Segerman B, Shin H, Siddiqui A, Sterky F, Terry A, Tsai CJ, Uberbacher E, Unneberg P, Vahala J, Wall K, Wessler S, Yang G, Yin T, Douglas C, Marra M, Sandberg G, Van de Peer Y, Rokhsar D (2006) The genome of black cottonwood, Populus trichocarpa (Torr. & Gray). Science 313:1596–1604CrossRefPubMedGoogle Scholar