title: Gene expression analysis of disabled and re-induced isoprene emission by the tropical tree Ficus septica before and after cold ambient temperature exposure.
abstract: Isoprene is the most abundant type of nonmethane, biogenic volatile organic compound in the atmosphere, and it is produced mainly by terrestrial plants. The tropical tree species Ficus septica Burm. F. (Rosales: Moraceae) has been shown to cease isoprene emissions when exposed to temperatures of 12 °C or lower and to re-induce isoprene synthesis upon subsequent exposure to temperatures of 30 °C or higher for 24 h. To elucidate the regulation of genes underlying the disabling and then induction of isoprene emission during acclimatization to ambient temperature, we conducted gene expression analyses of F. septica plants under changing temperature using quantitative real-time polymerase chain reaction and western blotting. Transcription levels were analyzed for 17 genes that are involved in metabolic pathways potentially associated with isoprene biosynthesis, including isoprene synthase (ispS). The protein levels of ispS were also measured. Changes in transcription and protein levels of the ispS gene, but not in the other assessed genes, showed identical temporal patterns to isoprene emission capacity under the changing temperature regime. The ispS protein levels strongly and positively correlated with isoprene emission capacity (R(2) = 0.92). These results suggest that transcriptional regulation of ispS gave rise to the temporal variation in isoprene emission capacity in response to changing temperature.
authors.affiliation: Tropical Biosphere Research Center, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan; United Graduate School of Agricultural Sciences, Kagoshima University, Korimoto 1-21-24, Kagoshima 890-0065, Japan;
authors.forename: Ishmael
authors.initials: I
authors.lastname: Mutanda
authors.affiliation: Tropical Biosphere Research Center, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan; h109296@comb.u-ryukyu.ac.jp.
authors.forename: Seikoh
authors.initials: S
authors.lastname: Saitoh
authors.affiliation: Tropical Biosphere Research Center, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan;
authors.forename: Masashi
authors.initials: M
authors.lastname: Inafuku
authors.affiliation: Tropical Biosphere Research Center, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan; Faculty of Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan;
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Aoyama
authors.affiliation: Tropical Biosphere Research Center, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan; Graduate School of Agriculture, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan;
authors.forename: Tomonori
authors.initials: T
authors.lastname: Takamine
authors.affiliation: Okinawa Institute of Advanced Sciences, Suzaki 5-1, Uruma, Okinawa 904-2234, Japan;
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Satou
authors.affiliation: Tokai University, Toroku 9-1-1, Higashi-ku, Kumamoto 862-8652, Japan;
authors.forename: Masako
authors.initials: M
authors.lastname: Akutsu
authors.affiliation: Okinawa Institute of Advanced Sciences, Suzaki 5-1, Uruma, Okinawa 904-2234, Japan;
authors.forename: Kuniko
authors.initials: K
authors.lastname: Teruya
authors.affiliation: Okinawa Institute of Advanced Sciences, Suzaki 5-1, Uruma, Okinawa 904-2234, Japan;
authors.forename: Hinako
authors.initials: H
authors.lastname: Tamotsu
authors.affiliation: Okinawa Institute of Advanced Sciences, Suzaki 5-1, Uruma, Okinawa 904-2234, Japan;
authors.forename: Makiko
authors.initials: M
authors.lastname: Shimoji
authors.affiliation: Tropical Biosphere Research Center, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan; Okinawa Prefectural Agricultural Research Center, Makabe 820, Itoman, Okinawa 901-0336, Japan.
authors.forename: Haruki
authors.initials: H
authors.lastname: Sunagawa
authors.affiliation: Tropical Biosphere Research Center, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan;
authors.forename: Hirosuke
authors.initials: H
authors.lastname: Oku
mesh_terms: D000064:Acclimatization / Q000235:genetics*; D019883:Alkyl and Aryl Transferases / Q000235:genetics* / Q000378:metabolism; D002070:Butadienes / Q000378:metabolism*; D003080:Cold Temperature; D030681:Ficus / Q000378:metabolism / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D045782:Hemiterpenes / Q000378:metabolism*; D053858:Metabolic Networks and Pathways / Q000235:genetics; D010420:Pentanes / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D013312:Stress, Physiological; D014158:Transcription, Genetic; D014197:Trees / Q000378:metabolism / Q000502:physiology; D014329:Tropical Climate
chemical_list: D002070:Butadienes; D045782:Hemiterpenes; D010420:Pentanes; D010940:Plant Proteins; C005059:isoprene; D019883:Alkyl and Aryl Transferases; C093854:isoprene synthase
keywords: BVOC; basal isoprene emission factor