title: Thermotolerant cyclamen with reduced acrolein and methyl vinyl ketone.
abstract: Reduced levels of trienoic fatty acids (TAs) in chloroplast membranes induce thermotolerance in several plant species, but the underlying mechanisms remain unclear. TA peroxidation in plant cell membranes generates cytotoxic, TA-derived compounds containing α,β-unsaturated carbonyl groups. The relationship between low TA levels and the amounts of cytotoxic TA-derived compounds was examined using thermotolerant transgenic cyclamen (Cyclamen persicum Mill.) with low TA contents. Changes in the levels of the cytotoxic TA-derived acrolein (ACR), methyl vinyl ketone (MVK), (E)-2-hexenal, 4-hydroxy-2-nonenal, and malondialdehyde were analysed in the leaf tissues of wild-type (WT) and thermotolerant transgenic cyclamen under heat stress. Levels of ACR and MVK in the WT increased in parallel with the occurrence of heat-induced tissue damage, whereas no such changes were observed in the thermotolerant transgenic lines. Furthermore, exogenous ACR and MVK infiltrated into leaves to concentrations similar to those observed in heat-stressed WT leaves caused similar disease symptoms. These results suggest that thermotolerance in transgenic cyclamen depends on reduced production rates of ACR and MVK under heat stress, due to the low level of TAs in these plants.
authors.affiliation: Fukuoka Agricultural Research Center, 587 Yoshiki, Chikushino, Fukuoka, 818-8549 Japan.
authors.forename: Hiroomi
authors.initials: H
authors.lastname: Kai
authors.forename: Keita
authors.initials: K
authors.lastname: Hirashima
authors.forename: Osamu
authors.initials: O
authors.lastname: Matsuda
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Ikegami
authors.forename: Traud
authors.initials: T
authors.lastname: Winkelmann
authors.forename: Takao
authors.initials: T
authors.lastname: Nakahara
authors.forename: Koh
authors.initials: K
authors.lastname: Iba
mesh_terms: D000171:Acrolein / Q000378:metabolism*; D002074:Butanones / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism*; D031824:Cyclamen / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006358:Hot Temperature; D018515:Plant Leaves / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D002074:Butanones; D000171:Acrolein; C057920:3-buten-2-one