Publications by authors named "Vicky Oberkofler"

4 Publications

  • Page 1 of 1

Heteromeric HSFA2/HSFA3 complexes drive transcriptional memory after heat stress in Arabidopsis.

Nat Commun 2021 06 8;12(1):3426. Epub 2021 Jun 8.

Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany.

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.
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http://dx.doi.org/10.1038/s41467-021-23786-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8187452PMC
June 2021

Epigenetic regulation of abiotic stress memory: maintaining the good things while they last.

Curr Opin Plant Biol 2021 06 8;61:102007. Epub 2021 Feb 8.

University of Potsdam, Institute for Biochemistry and Biology, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam, Germany. Electronic address:

As sessile organisms, plants have evolved sophisticated ways to constantly gauge and adapt to changing environmental conditions including extremes that may be harmful to their growth and development and are thus perceived as stress. In nature, stressful events are often chronic or recurring and thus an initial stress may prime a plant to respond more efficiently to a subsequent stress event. An epigenetic basis of such stress memory was long postulated and in recent years it has been shown that this is indeed the case. High temperature stress has proven an excellent system to unpick the molecular basis of somatic stress memory, which includes histone modifications and nucleosome occupancy. This review discusses recent findings and pinpoints open questions in the field.
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http://dx.doi.org/10.1016/j.pbi.2021.102007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8250047PMC
June 2021

Development of a universal endogenous qPCR control for eukaryotic DNA samples.

Plant Methods 2020 16;16:53. Epub 2020 Apr 16.

Applied Genomics and Molecular Biology, Institute for Plant Health, Laimburg Research Centre, Pfatten, Italy.

Background: Phytoplasma are obligate intracellular plant-pathogenic bacteria that infect a broad range of plant species and are transmitted by different insect species. Quantitative real-time PCR (qPCR) is one of the most commonly used techniques for pathogen detection, especially for pathogens that cannot be cultivated outside their host like phytoplasma. PCR analysis requires the purification of total DNA from the sample and subsequent amplification of pathogen DNA with specific primers. The purified DNA contains mainly host DNA and only a marginal proportion is of phytoplasmal origin. Therefore, detection of phytoplasma DNA in a host DNA background must be sensitive, specific and reliable and is highly dependent on the quality and concentration of the purified DNA. DNA quality and concentration and the presence of PCR-inhibitors therefore have a direct impact on pathogen detection. Thus, it is indispensable for PCR-based diagnostic tests to validate the DNA preparation and DNA integrity before interpreting diagnostic results, especially in case that no pathogen DNA is detected. The use of an internal control allows to evaluate DNA integrity and the detection of PCR-inhibiting substances. Internal controls are generally host-specific or limited to a defined group of related species. A control suitable for the broad range of phytoplasma hosts comprising different insect and plant species is still missing.

Results: We developed a primer and probe combination that allows amplification of a conserved stretch of the eukaryotic 28S rDNA gene. The developed endogenous qPCR control serves as a DNA quality control and allows the analysis of different eukaryotic host species, including plants, insects, fish, fungi, mammals and human with a single primer/probe set in single- or multiplex assays.

Conclusions: Quality and performance control is indispensable for pathogen detection by qPCR. Several plant pathogens are transmitted by insects and have a broad range of host species. The newly developed endogenous control can be used with all so far tested eukaryotic species and since multiplexing is possible, the described primer and probe set can be easily combined with other PCR-based pathogen detection systems.
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http://dx.doi.org/10.1186/s13007-020-00597-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7160944PMC
April 2020

Wide transcriptional investigation unravel novel insights of the on-tree maturation and postharvest ripening of 'Abate Fetel' pear fruit.

Hortic Res 2019 1;6:32. Epub 2019 Mar 1.

1Department of Genomics and Biology of Fruit Crops, Research and Innovation Centre, Fondazione Edmund Mach (FEM), Via E. Mach 1, 38010 San Michele all'Adige, Italy.

To decipher the transcriptomic regulation of the on-tree fruit maturation in pear cv. 'Abate Fetel', a RNA-seq transcription analysis identified 8939 genes differentially expressed across four harvesting stages. These genes were grouped into 11 SOTA clusters based on their transcriptional pattern, of which three included genes upregulated while the other four were represented by downregulated genes. Fruit ripening was furthermore investigated after 1 month of postharvest cold storage. The most important variation in fruit firmness, production of ethylene and volatile organic compounds were observed after 5 days of shelf-life at room temperature following cold storage. The role of ethylene in controlling the ripening of 'Abate Fetel' pears was furthermore investigated through the application of 1-methylcyclopropene, which efficiently delayed the progression of ripening by reducing fruit softening and repressing both ethylene and volatile production. The physiological response of the interference at the ethylene receptor level was moreover unraveled investigating the expression pattern of 12 candidate genes, initially selected to validate the RNA-seq profile. This analysis confirmed the effective role of the ethylene competitor in downregulating the expression of cell wall (PG) and ethylene-related genes (ACS, ACO, ERS1, and ERS2), as well as inducing one element involved in the auxin signaling pathway (Aux/IAA), highlighting a possible cross-talk between these two hormones. The expression patterns of these six elements suggest their use as molecular toolkit to monitor at molecular level the progression of the fruit on-tree maturation and postharvest ripening.
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http://dx.doi.org/10.1038/s41438-018-0115-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6395599PMC
March 2019
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