TY - THES A1 - Lämke, Jörn T1 - Determining the future in the past BT - analysis of the role of chromation in heat stress memory in Arabidopsis thaliana Y1 - 2015 ER - TY - JOUR A1 - Liu, Hsiang-chin A1 - Lämke, Jörn A1 - Lin, Siou-ying A1 - Hung, Meng-Ju A1 - Liu, Kuan-Ming A1 - Charng, Yee-yung A1 - Bäurle, Isabel T1 - Distinct heat shock factors and chromatin modifications mediate the organ-autonomous transcriptional memory of heat stress JF - The plant journal N2 - Plants can be primed by a stress cue to mount a faster or stronger activation of defense mechanisms upon subsequent stress. A crucial component of such stress priming is the modified reactivation of genes upon recurring stress; however, the underlying mechanisms of this are poorly understood. Here, we report that dozens of Arabidopsis thaliana genes display transcriptional memory, i.e. stronger upregulation after a recurring heat stress, that lasts for at least 3 days. We define a set of transcription factors involved in this memory response and show that the transcriptional memory results in enhanced transcriptional activation within minutes of the onset of a heat stress cue. Further, we show that the transcriptional memory is active in all tissues. It may last for up to a week, and is associated during this time with histone H3 lysine 4 hypermethylation. This transcriptional memory is cis-encoded, as we identify a promoter fragment that confers memory onto a heterologous gene. In summary, heat-induced transcriptional memory is a widespread and sustained response, and our study provides a framework for future mechanistic studies of somatic stress memory in higher plants. KW - epigenetics KW - priming KW - heat stress KW - H3K4 methylation KW - transcriptional memory KW - Arabidopsis thaliana KW - HSF Y1 - 2018 U6 - https://doi.org/10.1111/tpj.13958 SN - 0960-7412 SN - 1365-313X VL - 95 IS - 3 SP - 401 EP - 413 PB - Wiley CY - Hoboken ER - TY - GEN A1 - Lämke, Jörn A1 - Bäurle, Isabel T1 - Epigenetic and chromatin-based mechanisms in environmental stress adaptation and stress memory in plants T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Plants frequently have to weather both biotic and abiotic stressors, and have evolved sophisticated adaptation and defense mechanisms. In recent years, chromatin modifications, nucleosome positioning, and DNA methylation have been recognized as important components in these adaptations. Given their potential epigenetic nature, such modifications may provide a mechanistic basis for a stress memory, enabling plants to respond more efficiently to recurring stress or even to prepare their offspring for potential future assaults. In this review, we discuss both the involvement of chromatin in stress responses and the current evidence on somatic, intergenerational, and transgenerational stress memory. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 792 KW - remodeling atpase brahma KW - transcriptional memory KW - DNA methylation KW - transgenerational inheritance KW - acquired thermotolerance KW - Arabidopsis-thaliana KW - gene-expression KW - responses KW - protein KW - defense Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-436236 SN - 1866-8372 IS - 792 ER - TY - JOUR A1 - Lämke, Jörn. S. A1 - Unsicker, Sybille Barbara T1 - Phytochemical variation in treetops BT - causes and consequences for tree-insect herbivore interactions JF - Oecologia N2 - The interaction of plants and their herbivorous opponents has shaped the evolution of an intricate network of defences and counter-defences for millions of years. The result is an astounding diversity of phytochemicals and plant strategies to fight and survive. Trees are specifically challenged to resist the plethora of abiotic and biotic stresses due to their dimension and longevity. Here, we review the recent literature on the consequences of phytochemical variation in trees on insect-tree-herbivore interactions. We discuss the importance of genotypic and phenotypic variation in tree defence against insects and suggest some molecular mechanisms that might bring about phytochemical diversity in crowns of individual trees. KW - Chromatin-based mechanisms KW - Genotypic variation KW - Insect herbivore KW - Phenotypic plasticity KW - Tree defence Y1 - 2018 U6 - https://doi.org/10.1007/s00442-018-4087-5 SN - 0029-8549 SN - 1432-1939 VL - 187 IS - 2 SP - 377 EP - 388 PB - Springer CY - New York ER - TY - JOUR A1 - Lämke, Jörn A1 - Brzezinka, Krzysztof A1 - Altmann, Simone A1 - Bäurle, Isabel T1 - A hit-and-run heat shock factor governs sustained histone methylation and transcriptional stress memory JF - The EMBO journal N2 - In nature, plants often encounter chronic or recurring stressful conditions. Recent results indicate that plants can remember a past exposure to stress to be better prepared for a future stress incident. However, the molecular basis of this is poorly understood. Here, we report the involvement of chromatin modifications in the maintenance of acquired thermotolerance (heat stress [HS] memory). HS memory is associated with the accumulation of histone H3 lysine 4 di- and trimethylation at memory-related loci. This accumulation outlasts their transcriptional activity and marks them as recently transcriptionally active. High accumulation of H3K4 methylation is associated with hyper-induction of gene expression upon a recurring HS. This transcriptional memory and the sustained accumulation of H3K4 methylation depend on HSFA2, a transcription factor that is required for HS memory, but not initial heat responses. Interestingly, HSFA2 associates with memory-related loci transiently during the early stages following HS. In summary, we show that transcriptional memory after HS is associated with sustained H3K4 hyper-methylation and depends on a hit-and-run transcription factor, thus providing a molecular framework for HS memory. KW - chromatin KW - H3K4 methylation KW - heat shock transcription factor KW - priming KW - transcriptional memory Y1 - 2016 U6 - https://doi.org/10.15252/embj.201592593 SN - 0261-4189 SN - 1460-2075 VL - 35 SP - 162 EP - 175 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Lämke, Jörn A1 - Bäurle, Isabel T1 - Epigenetic and chromatin-based mechanisms in environmental stress adaptation and stress memory in plants JF - Genome biology : biology for the post-genomic era N2 - Plants frequently have to weather both biotic and abiotic stressors, and have evolved sophisticated adaptation and defense mechanisms. In recent years, chromatin modifications, nucleosome positioning, and DNA methylation have been recognized as important components in these adaptations. Given their potential epigenetic nature, such modifications may provide a mechanistic basis for a stress memory, enabling plants to respond more efficiently to recurring stress or even to prepare their offspring for potential future assaults. In this review, we discuss both the involvement of chromatin in stress responses and the current evidence on somatic, intergenerational, and transgenerational stress memory. KW - remodeling atpase brahma KW - transcriptional memory KW - DNA methylation KW - transgenerational inheritance KW - acquired thermotolerance KW - Arabidopsis-thaliana KW - gene-expression KW - responses KW - protein KW - defense Y1 - 2017 U6 - https://doi.org/10.1186/s13059-017-1263-6 SN - 1474-760X VL - 18 SP - 8685 EP - 8693 PB - BioMed Central CY - London ER - TY - JOUR A1 - Friedrich, Thomas A1 - Oberkofler, Vicky A1 - Trindade, Inês A1 - Altmann, Simone A1 - Brzezinka, Krzysztof A1 - Lämke, Jörn S. A1 - Gorka, Michal A1 - Kappel, Christian A1 - Sokolowska, Ewelina A1 - Skirycz, Aleksandra A1 - Graf, Alexander A1 - Bäurle, Isabel T1 - Heteromeric HSFA2/HSFA3 complexes drive transcriptional memory after heat stress in Arabidopsis JF - Nature Communications N2 - Adaptive plasticity in stress responses is a key element of plant survival strategies. For instance, moderate heat stress (HS) primes a plant to acquire thermotolerance, which allows subsequent survival of more severe HS conditions. Acquired thermotolerance is actively maintained over several days (HS memory) and involves the sustained induction of memory-related genes. Here we show that FORGETTER3/ HEAT SHOCK TRANSCRIPTION FACTOR A3 (FGT3/HSFA3) is specifically required for physiological HS memory and maintaining high memory-gene expression during the days following a HS exposure. HSFA3 mediates HS memory by direct transcriptional activation of memory-related genes after return to normal growth temperatures. HSFA3 binds HSFA2, and in vivo both proteins form heteromeric complexes with additional HSFs. Our results indicate that only complexes containing both HSFA2 and HSFA3 efficiently promote transcriptional memory by positively influencing histone H3 lysine 4 (H3K4) hyper-methylation. In summary, our work defines the major HSF complex controlling transcriptional memory and elucidates the in vivo dynamics of HSF complexes during somatic stress memory. Moderate heat stress primes plants to acquire tolerance to subsequent, more severe heat stress. Here the authors show that the HSFA3 transcription factor forms a heteromeric complex with HSFA2 to sustain activated transcription of genes required for acquired thermotolerance by promoting H3K4 hyper-methylation. Y1 - 2021 U6 - https://doi.org/10.1038/s41467-021-23786-6 SN - 2041-1723 VL - 12 IS - 1 PB - Nature Publishing Group UK CY - [London] ER -