TY  - JOUR
A1  - Münch, Miriam
A1  - Hsin, Chih-Hsuan
A1  - Ferber, Elena
A1  - Berger, Susanne
A1  - Müller, Martin J.
T1  - Reactive electrophilic oxylipins trigger a heat stress-like response through HSFA1 transcription factors
JF  - Journal of Experimental Botany
N2  - Electrophilic oxylipins trigger a heat-shock-like response in the absence of heat through the canonical heat-shock transcription factor A1, thereby helping to cope with stresses associated with protein damage.Abiotic and biotic stresses are often characterized by an induction of reactive electrophile species (RES) such as the jasmonate 12-oxo-phytodienoic acid (OPDA) or the structurally related phytoprostanes. Previously, RES oxylipins have been shown massively to induce heat-shock-response (HSR) genes including HSP101 chaperones. Moreover, jasmonates have been reported to play a role in basal thermotolerance. We show that representative HSR marker genes are strongly induced by RES oxylipins through the four master regulator transcription factors HSFA1a, b, d, and e essential for short-term adaptation to heat stress in Arabidopsis. When compared with Arabidopsis seedlings treated at the optimal acclimation temperature of 37 A degrees C, the exogenous application of RES oxylipins at 20 A degrees C induced a much weaker induction of HSP101 at both the gene and protein expression levels which, however, was not sufficient to confer short-term acquired thermotolerance. Moreover, jasmonate-deficient mutant lines displayed a wild-type-like HSR and were not compromised in acquiring thermotolerance. Hence, the OPDA- and RES oxylipin-induced HSR is not sufficient to protect seedlings from severe heat stress but may help plants to cope better with stresses associated with protein unfolding by inducing a battery of chaperones in the absence of heat.
KW  - arabidopsis-thaliana
KW  - shock response
KW  - gene-expression
KW  - model
KW  - acquired thermotolerance
KW  - 12-oxo-phytodienoic acid
KW  - thermotolerance
KW  - plants
KW  - detoxification
KW  - acquisition
KW  - activation
KW  - heat stress
KW  - jasmonates
KW  - phytoprostanes
KW  - reactive electrophilic species
KW  - unfolded protein response
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186766
VL  - 67
IS  - 21
ER  - 
TY  - JOUR
A1  - Stotz, Henrik U.
A1  - Mueller, Stefan
A1  - Zoeller, Maria
A1  - Mueller, Martin J.
A1  - Berger, Susanne
T1  - TGA transcription factors and jasmonate-independent COI1 signalling regulate specific plant responses to reactive oxylipins
JF  - Journal of Experimental Botany
N2  - Jasmonates and phytoprostanes are oxylipins that regulate stress responses and diverse physiological and developmental processes. 12-Oxo-phytodienoic acid (OPDA) and phytoprostanes are structurally related electrophilic cyclopentenones, which activate similar gene expression profiles that are for the most part different from the action of the cyclopentanone jasmonic acid (JA) and its biologically active amino acid conjugates. Whereas JA–isoleucine signals through binding to COI1, the bZIP transcription factors TGA2, TGA5, and TGA6 are involved in regulation of gene expression in response to phytoprostanes. Here root growth inhibition and target gene expression were compared after treatment with JA, OPDA, or phytoprostanes in mutants of the COI1/MYC2 pathway and in different TGA factor mutants. Inhibition of root growth by phytoprostanes was dependent on COI1 but independent of jasmonate biosynthesis. In contrast, phytoprostane-responsive gene expression was strongly dependent on TGA2, TGA5, and TGA6, but not dependent on COI1, MYC2, TGA1, and TGA4. Different mutant and overexpressing lines were used to determine individual contributions of TGA factors to cyclopentenone-responsive gene expression. Whereas OPDA-induced expression of the cytochrome P450 gene CYP81D11 was primarily regulated by TGA2 and TGA5, the glutathione S-transferase gene GST25 and the OPDA reductase gene OPR1 were regulated by TGA5 and TGA6, but less so by TGA2. These results support the model that phytoprostanes and OPDA regulate differently (i) growth responses, which are COI1 dependent but jasmonate independent; and (ii) lipid stress responses, which are strongly dependent on TGA2, TGA5, and TGA6. Identification of molecular components in cyclopentenone signalling provides an insight into novel oxylipin signal transduction pathways.
KW  - lipid signaling
KW  - reactive electrophile oxylipins
KW  - detoxification
KW  - class II TGA factors
KW  - biotic and abiotic stress
KW  - arabidopsis thaliana
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-132318
VL  - 64
IS  - 4
ER  -