Zahide Aslan (Goethe Universität Frankfurt)
Zahide Aslan's Master thesis was awarded with the Prize for the Best Plant Science Master Thesis, which was carried out at Frankfurt University in the year 2023 with the title:
Regulation of heat stress-responsive genes by class B heat stress transcription factors in tomato
Aslans work provides first evidence that the formation of a putative HsfA1a-HAC1-HsfB1 ternary activator complex might be important for the acetylation of histone 3 (H3K9ac), thereby directly linking the transcription factor function to chromatin changes that are related to transcription – a link that is currently not well described regarding heat stress response.
The response to heat stress is dependent primarily on changes in gene expression. Genes coding for survival of the cell are essential and need to be synthesized promptly. Transcription factors play central role, but their activity is associated with chromatin structure: the complex of DNA and proteins within the cell nucleus. This association influences how accessible specific genes are for transcription, impacting the cell's ability to rapidly produce the necessary proteins for survival during heat stress. Using transcription factor activator assays in isolated tomato protoplasts in combination with CRISPR-mediated mutation Aslan showed that class B heat stress transcription factors (HSF) can act as co-activators in the presence of histone acetyltransferases. This was also supported by expression analysis in plants in which HSFB1 was overexpressed using a pharmacological approach, by application of chemicals that either inhibit the activity of histone acetyltransferases or the activity of de-acetyltransferases. Importantly using chromatin immunoprecipitation assay Aslan showed that the alterations in gene expression are associated with changes in histone acetylation in HSF-target genes. These findings provide evidence that the activity of a transcription factor can be directly linked to chromatin structure and thereby contribute to the global changes in gene expression under heat stress.
Read Master thesis: https://www.bio.uni-frankfurt.de/58896237/Heat_Stress
Read paper: Guarino F, Cicatelli A, Castiglione S, Agius DR, Orhun GE, Fragkostefanakis S, Leclercq J, Dobránszki J, Kaiserli E, Lieberman-Lazarovich M, Sõmera M, Sarmiento C, Vettori C, Paffetti D, Poma AMG, Moschou PN, Gašparović M, Yousefi S, Vergata C, Berger MMJ, Gallusci P, Miladinović D and Martinelli F (2022) An Epigenetic Alphabet of Crop Adaptation to Climate Change. Front. Genet. 13: 818727. doi: 10.3389/fgene.2022.818727
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Zahide Aslan conducted this work at the Institute of Molecular Biosciences in the working group led by Dr. Sotirios Fragkostefanakis focusing on the molecular and cellular mechanisms in plants.
