@article{StiefAltmannHoffmannetal.2014, author = {Stief, Anna and Altmann, Simone and Hoffmann, Karen and Pant, Bikram Datt and Scheible, Wolf-R{\"u}diger and B{\"a}urle, Isabel}, title = {Arabidopsis miR156 regulates tolerance to recurring environmental stress through SPL transcription factors}, series = {The plant cell}, volume = {26}, journal = {The plant cell}, number = {4}, publisher = {American Society of Plant Physiologists}, address = {Rockville}, issn = {1040-4651}, doi = {10.1105/tpc.114.123851}, pages = {1792 -- 1807}, year = {2014}, abstract = {Plants are sessile organisms that gauge stressful conditions to ensure survival and reproductive success. While plants in nature often encounter chronic or recurring stressful conditions, the strategies to cope with those are poorly understood. Here, we demonstrate the involvement of ARGONAUTE1 and the microRNA pathway in the adaptation to recurring heat stress (HS memory) at the physiological and molecular level. We show that miR156 isoforms are highly induced after HS and are functionally important for HS memory. miR156 promotes sustained expression of HS-responsive genes and is critical only after HS, demonstrating that the effects of modulating miR156 on HS memory do not reflect preexisting developmental alterations. miR156 targets SPL transcription factor genes that are master regulators of developmental transitions. SPL genes are posttranscriptionally downregulated by miR156 after HS, and this is critical for HS memory. Altogether, the miR156-SPL module mediates the response to recurring HS in Arabidopsis thaliana and thus may serve to integrate stress responses with development.}, language = {en} } @article{KabelitzKappelHennebergeretal.2014, author = {Kabelitz, Tina and Kappel, Christian and Henneberger, Kirstin and Benke, Eileen and Noeh, Christiane and B{\"a}urle, Isabel}, title = {eQTL mapping of transposon silencing reveals a position-dependent stable escape from epigenetic silencing and transposition of AtMu1 in thee arabidopsis lineage}, series = {The plant cell}, volume = {26}, journal = {The plant cell}, number = {8}, publisher = {American Society of Plant Physiologists}, address = {Rockville}, issn = {1040-4651}, doi = {10.1105/tpc.114.128512}, pages = {3261 -- 3271}, year = {2014}, abstract = {Transposons are massively abundant in all eukaryotic genomes and are suppressed by epigenetic silencing. Transposon activity contributes to the evolution of species; however, it is unclear how much transposition-induced variation exists at a smaller scale and how transposons are targeted for silencing. Here, we exploited differential silencing of the AtMu1c transposon in the Arabidopsis thaliana accessions Columbia (Col) and Landsberg erecta (Ler). The difference persisted in hybrids and recombinant inbred lines and was mapped to a single expression quantitative trait locus within a 20-kb interval. In Ler only, this interval contained a previously unidentified copy of AtMu1c, which was inserted at the 39 end of a protein-coding gene and showed features of expressed genes. By contrast, AtMu1c(Col) was intergenic and associated with heterochromatic features. Furthermore, we identified widespread natural AtMu1c transposition from the analysis of over 200 accessions, which was not evident from alignments to the reference genome. AtMu1c expression was highest for insertions within 39 untranslated regions, suggesting that this location provides protection from silencing. Taken together, our results provide a species-wide view of the activity of one transposable element at unprecedented resolution, showing that AtMu1c transposed in the Arabidopsis lineage and that transposons can escape epigenetic silencing by inserting into specific genomic locations, such as the 3' end of genes.}, language = {en} }