Plants utilize isoprene emission as a thermotolerance mechanism.
Isoprene is a volatile compound emitted from leaves of many plant species in large quantities, which has an impact on atmospheric chemistry due to its massive global emission rate (5 x 10(14) carbon g year(-1)) and its high reactivity with the OH radical, resulting in an increase in the half-life of methane. Isoprene emission is strongly induced by the increase in isoprene synthase activity in plastids at high temperature in the day time, which is regulated at its gene expression level in leaves, while the physiological meaning of isoprene emission for plants has not been clearly demonstrated. In this study, we have functionally overexpressed Populus alba isoprene synthase in Arabidopsis to observe isoprene emission from transgenic plants. A striking difference was observed when both transgenic and wild-type plants were treated with heat at 60 degrees C for 2.5 h, i.e. transformants revealed clear heat tolerance compared with the wild type. High isoprene emission and a decrease in the leaf surface temperature were observed in transgenic plants under heat stress treatment. In contrast, neither strong light nor drought treatments showed an apparent difference. These data suggest that isoprene emission plays a crucial role in a heat protection mechanism in plants.
Sasaki
Kanako
K
Laboratory of Plant Gene Expression, Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji, Japan.
Saito
Takuya
T
Lämsä
Mari
M
Oksman-Caldentey
Kirsi-Marja
KM
Suzuki
Masashi
M
Ohyama
Kiyoshi
K
Muranaka
Toshiya
T
Ohara
Kazuaki
K
Yazaki
Kazufumi
K
D019883:Alkyl and Aryl Transferases / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002070:Butadienes; D018506:Gene Expression Regulation, Plant; D045782:Hemiterpenes / Q000096:biosynthesis*; D006358:Hot Temperature; D010420:Pentanes; D018515:Plant Leaves / Q000201:enzymology / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000378:metabolism; D018087:Plastids / Q000201:enzymology / Q000378:metabolism; D032107:Populus / Q000201:enzymology / Q000235:genetics
D002070:Butadienes; D045782:Hemiterpenes; D010420:Pentanes; C005059:isoprene; D019883:Alkyl and Aryl Transferases; C093854:isoprene synthase